Library

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (630)
  • Industrial Chemistry and Chemical Engineering  (629)
  • Nuclear reactions
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 127-130 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A novel reactor arrangement for the anionic polymerization of styrene described in this paper comprises alternating adiabatically operated plug-flow reactors and heat exchangers. A novel tube-bundle recycle reactor is presented for the bulk polymerization of styrene and acrylonitrile.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 138-140 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The reaction in aqueous solutions between carbon disulphide and morpholine has been studied experimentally at 303 K using a conductimetric stopped-flow technique. The observed pseudo-first order rate constant does not vary linearly with amine concentration but follows the equation: \documentclass{article}\pagestyle{empty}\begin{document}$$ k_{obs} = k_{Am} [R_2 NH]^2 + k_w [R_2 NH][H_2 O] $$\end{document} .This equation is compatible both with (i) zwitterion intermediate and (ii) single-step termolecular reaction mechanisms which were previously proposed for the corresponding reactions of CO2 and COS. Values of rate constants kAm and kw at 303 K are also reported.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 365-373 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The productivity of fermentations is often limited by end product inhibition. This can be avoided by continuous removal of the inhibiting product from the broth. Such in-situ separation can be conveniently accomplished by liquid-liquid extraction. As an example, the continuous fermentation of ethanol by the thermophilic, anaerobic bacterium Clostridium thermohydrosulfuricum is investigated in a 20-1 fermenter with simultaneous in-situ extraction by oleyl alcohol as organic solvent. Continuous fermentations with and without in-situextraction were carried out with systematic variation of the independent operating conditions, viz. feed glucose concentration, broth flow rate and solvent flow rate. The experimental results of 18 steady states are reported. They show that in-situ extractions doubles the yield, selectivity and space-time yield of ethanol in comparison to fermentations without in-situ extraction. A biomodel elucidates the influence of feed glucose concentration, broth flow rate and solvent flow rate on the productivity of the fermentation process. Finally, a cost model was developed for the investigated fermentation which allows economic evaluation of the results of experiments and simulation. A sensitivity study elucidates the economic limits and advantages of fermentation with in-situ extraction compared to a common fermentation without product separation.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Gas diffusion electrodes, made of PTFE-bonded carbon with precious metal catalysts, were investigated as hydrogen consuming anodes in sodium sulphate electrolysis. The catalysts used were platinum and palladium and mixtures of both metals, prepared by two different methods. Various metal meshes were used as current collector. The electrodes performed well in pure sulphuric acid (5-15 wt-%) and in mixtures with sodium sulphate (10 wt-%) at temperatures of 30 to 70°C and current densities up to 5 kA/m2. In long-term experiments, at a current density of 2.6 kA/m2, the electrodes were stable over three months. The electrodes were characterised by stationary current density/potential curves and by galvanostatic current interruption measurements.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 242-248 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The purpose of this paper is to investigate the swelling of emulsion liquid membranes using dithio-DEHPA as carrier. The application of interest was the removal of zinc from a synthetic aqueous solution which simulates a zinc plant effluent. The effect of several variables such as the concentration of carrier in the membrane, stirring speed and permeation time on the swelling of the emulsion is reported. Experimental results show that occlusion depends mainly on the amount of carrier in the membrane and can be significant when the concentration of carrier is lower than 6.0%. The interfacial tension analysis confirms that the size of globules is influenced by the concentration of carrier in the membrane. Stirring speed and permeation time are related to the water transport and must be kept at low values.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Process models are used to formulate knowledge about process behaviour. They are applied, e.g., to predict the process' future behaviour and for state estimation when reliable on-line measuring techniques to monitor the key variables of the process are not available. There are different sources of information available for modelling, which provide process knowledge in different representations. Some elements or aspects may be described by physically based mathematical models and others by heuristically obtained rules of thumb, while some information may still be hidden in the process data recorded during previous runs of the process. Heuristic rules are conveniently processed with fuzzy expert systems, while artificial neural networks present themselves as a powerful tool for uncovering the information within the process data without the need to transform the information into one of the other representations. Artificial neural networks and fuzzy technology are increasingly being employed for modelling biotechnological processes, thus extending the traditional way of process modelling by mathematical equations. However, a sufficiently comprehensive combination of all these techniques has not yet been put forward. Here, we present a simple way of combining all the available knowledge relating to a given process. In a case study, we demonstrate the development of a hybrid model for state estimation and prediction on the example of a yeast production process. The model was validated during a cultivation performed in a standard pilot-scale fermenter.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 67-72 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The pyrolysis of polyvinyl chloride (PVC) has been described in terms of a relatively simple kinetic model, based on a large number of laboratory tests. The model predictions are in a good agreement with experimental data, regarding hydrochloric acid and non-condensable combustible gases. Therefore, the proposed model can be used to predict with good approximation the distributions of the above classes of compounds, in the whole range of applied experimental conditions.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994) 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 414-421 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Computer-aided design of a packed column to remove ethanol from aqueous solution with dibutyl butylphosphonate (DBBP) was accomplished with a programme based on the Pratt method and on the slip velocity equation. Reliable data for successful computation were obtained from literature correlations (drop size, hold-up and axial mixing coefficients for different types of packing) and from experimental work (equilibria and kinetics). Equilibrium studies on the H2O-ethanol-dibutyl butylphosphonate system were performed at different temperatures. A decrease in temperature increased the selectivity of the extractant while the distribution coefficient of ethanol, KD ≈ 1.0, remained constant. The behaviour of the system kinetics towards temperature is assessed in order to determine the initial mass transfer flux (892 × 10-3 kg m-2s-1, 30°C) and the activation energy, 22.9 kJ/kmol. The process is governed by the diffusion of the species involved. The influence of the type of packing of the column on its design is analyzed from the inventory volume of the solvent, the total volume of the column and the axial dispersion coefficients under normalised inlet and outlet conditions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994) 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 285-289 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In this study, a simple and effective technique for determining overall mass transfer coefficients in fixed bed sorption columns with recycle is presented. This new technique is free of the assumption of negligible time rate of solute concentration change in the fluid, i.e. (∂c/∂t) = 0, which has been widely used in former fixed bed sorption column analyses.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The results of experimental investigations on distillation columns operating on a lab and on a production scale are presented and compared with the results obtained by simulation. There is good agreement between experiment and simulation. On the basis of these results a dynamic analysis was carried out. It compares the dynamic behaviour of packed and plate distillation columns of the same diameter and same number of theoretical plates. This reflects the influence of the different hold-ups of the two columns.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 13
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Using methods of statistical thermodynamics, adsorption isotherms for the description of multicomponent chemisorption of different-sized molecular species are derived by assuming the adsorbing surface to be energetically homogeneous and by neglecting lateral interactions between the adsorbed particles. In the first part of this contribution, the adsorption equilibria for a mixture of different-sized chain molecules adsorbed on a lattice of coordination number z are discussed supposing each unit of a given chain to bind to one adsorption site only. In the second part, the coadsorption of molecular species consisting of a different number of segments on a continuous surface is treated. A comparison of the predicted to the measured isotherms for the coadsorption of two freon species on activated carbon shows that the proposed equations describe the results of the coadsorption measurements sufficiently well, provided the adsorption data for the pure components have been determined experimentally.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 325-337 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Single, binary, ternary and quaternary adsorption equilibria of CO2, CO, CH4 and N2 on molecular sieve 5A and activated carbon were experimentally determined over a pressure range from 10-4 to 101 MPa, a temperature range from 303 to 363 K and at various compositions. The adsorption equilibria of steam reformer gases as needed for the hydrogen purification in pressure swing adsorption units were measured by using a circulating volumetric method. For the temperature-dependent correlation of pure gas isotherm fields the Toth equation, which is a favorable model for heterogeneous adsorbents, was extended by two parameters accounting for the temperature-dependencies of the saturation loading and the heterogeneity parameter. Multicomponent equilibria were successfully predicted from single component isotherms by the Ideal Adsorbed Solution Theory based on the accurate representation of the pure component data by this temperature dependent Toth equation. Other thermodynamic models like the HIAS, the MIAS, the SPD or the VS theory and the Statistical Thermodynamics Model were also applied to the prediction of the adsorption equilibrium and the temperature and pressure dependence of the selectivity, with comparable success, which is due to the quasi-ideal adsorption behavior even at a high pressure.
    Additional Material: 24 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Manganese mixed oxide composite layers of about 1 μm thickness on titanium sheet as substrate were fabricated by firing of the corresponding nitrates at a typical temperature of 400°C in air. The activity of these anodes was evaluated by cyclic voltammetry (10 mV/s) and the stability was determined by chronopotentiometry (2.5 mA/cm2) in 1M H2SO4. The oxidation of 2-propanol was examined as a simple electroorganic model reaction. The quality of a first category of mixed oxides with general composition MnMe2O4 decresed in the order Me = Co, Ni, Fe. In a second group with the general formula MeMn2O4 a decrease in the order Me = Co, Cu, Fe, Ni, Ti, Zn, Cd, Ca, Mg, (Zn, Ge), Li was observed. The corresponding candidates of the second group were superior to those of the first. The anode service life τ of the optimum spinel anode CoMn2O4/Ti is dependent on the current density, according to jλ τ = const. (λ = 1.7). Thus high current densities are precluded. The mechanism has been discussed in terms of a heterogeneous redox catalysis: surface Mn(VII) states are formed in a slow electrochemical step. In a subsequent fast chemical oxidation of the organic molecule the original reduced state is regenerated. This also explains the comparatively good service life of these anodes.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 354-357 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A process for the manufacture of pure 4-methyl-1-pentene by catalytic dimerization of propylene has been developed in three stages. The first stage involves preparation of a new process catalyst, which contains metallic sodium and potassium deposited on a Bulgarian natural zeolite, the support having been passivated previously by potassium carbonate. The experimental results demonstrate the advantages of the resulting catalyst over exisisting technology, namely 36% conversion and 92% selectivity relevant to liquid isomers. The second development stage concerns the technological regime of chemical reaction for production of 4-methyl-1-pentene. In the third stage, the regime conditions and equipment ensuring desired quality of the product and utilization of the unreacted propylene returned to the reactor are determined. Based on the studies of all stages, a flowsheet is proposed for synthesis and separation of the reaction mixture of isomeric hexenes to give pure 4-methyl-1-pentene.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Titanium silicalite-1 samples of different particle size are synthesised and characterised by X-ray diffraction (XRD), photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), Raman and infrared spectroscopy. Size histograms are taken from transmission electron micrographs. Temporal changes of activity and selectivity for the hydroxylation of phenol and anisole are monitored. It is postulated that the p/o product ratios are due to the greater chemisorption of the ortho molecule.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 149-160 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Several kinds of diesel soot filters and filter materials of high melting points with eleven different catalytic coatings were prepared. They were calcined at a maximum temperature of 1000°C. The reaction rate and the kinetic parameters of the combustion of diesel soot were determined in a closed loop laboratory reactor. A packed bed of alumina particulates was the most active filter in soot combustion. Catalytic coatings with oxides of vanadium, copper or cerium accelerated the reaction. In each case the effect of the coating was dependent on specific interactions between the catalyst and the filter material. The manner of filtration and the nature of the soot filter are found to be more important for the overall result than the nature of the catalytic coating.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Combined XPS and SIMS measurements, partly supplemented by XRD investigations, were utilized to detect precious metal/support interactions on catalysts containing various precious metals. The Klemm-Bronger reaction between Pt and α-Al2O3 on methane/ammonia catalysts was used as a standard reference. Evidence was found for different stages of Pt/Al interactions and changing electronic properties of Pt on the surfaces of these Pt/α-Al2O3 catalysts by means of XPS and SIMS, and in the bulk material by XRD. The SIMS investigations on Pt and Rh on γ-Al2O3 showed that, even at temperatures around 500 °C, Rh/Al interactions can appear to a small extent in the topmost atomic layers, whereas the Pt/γ-Al2O3 specimens did not show any measurable effects. After on-road operation, enhanced SIMS cluster-ion signals as well as anomalous XPS signal contributions were measured on the surfaces of used three-way automotive emission control catalysts. These signals did not appear for the fresh catalysts. By analogy with the related results reported on the methane/ammonia catalysts, the ion signals were used as qualitative surface probes indicating the presence of precious metal/support interactions, especially between Rh and Al.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 20
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The catalytic oxidation of fluorene to 9-fluorenone in a fluidized-bed reactor was investigated by modeling of the reactor and simulation of its performance. The “Bubble Assemblage Model” of Kato and Wen, the “Bubbling Bed Model” of Kunii and Levenspiel and the “Countercurrent Backmixing Model” of Potter were applied. From a comparison of simulation results obtained by the various fluidized-bed models and a fixed-bed model conclusions were drawn about the influence of interphase mass transfer and gas backmixing on the conversion of fluorene and slectivity of 9-fluorenone formation. Furthermore, the dependence of conversion and selectivity on temperature and hydrodynamic conditions was investigated. In particular, the implications of a change of hydrodynamic conditions for scale-up were analysed. The highest yield of 9-fluorenone predicted for a bench-scale fluidized bed amounted to 88% (XF = 97%, SNON = 91%). This yield was lower than in a fixed-bed reactor (YNON = 92%, XF = 99%, SNON = 93%). A further drop of the yield was predicted when scaling-up from a bench-scale reactor to a commercial size unit (YNON = 54%, XF = 86%, SNON = 63%).
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 179-186 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The conversion of ethanol over H-ZSM-5 was studied as a function of ethanol partial pressure, reaction temperature, weight hourly space velocity and Si/Al ratio. The results obtained were in qualitative agreement with most of those in the literature. Combination with all published results to give a significant regression model was not possible due to the large scatter of the data from various scientific groups. In mechanistic investigations, temperature programmed reaction measurements of ethanol, diethyl ether and ethene were performed. The formation of ethene from ethanol via direct elimination or from diethyl ether as intermediate could be confirmed. In the conversion of ethanol/water mixtures, the product distribution did not change significantly up to a water content of 60 wt%. Then, a pronounced increase of ethene formation and a considerable decrease of the yields of aromatics was observed. When several reaction mixtures from syngas conversion to ethanol were converted over H-ZSM-5, the coking rate depended on the product distribution in the feed. Product mixtures from processes with higher amounts of compounds having an unfavourable C/H ratio led to rapid deactivation of the zeolite.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 187-194 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The formation of verbenol, verbenone and acids during liquid phase ozone-initiated oxidation of α-pinene has been investigated; temperature, ozone partial pressure and ozone initiation time were the variables studied. While increasing temperature promotes the formation of secondary products, the other two variables affect mainly the selectivity. Thus, an ozone partial pressure and ozone initiation time of 1014 Pa and 10 min, respectively, lead to the highest selectivities. Kinetic expressions for the formation of verbenol and verbenone, which are consistent with experimental data, have also been developed from a free radical mechanism.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 1-9 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In a process of precipitation, two or more reactants form a product. In many cases, the solubility of this product is very low and high supersaturation is generated which leads to nucleation and crystal growth. The number of the formed nuclei and their growth govern the particle size distribution of the precipitate. As a rule, the precipitate is separated from the mother liquor in a centrifuge or on a filter. This separation and the subsequent drying process of very fine particles can be very expensive with respect to investment and energy costs. Therefore, it is desirable to produce as coarse a precipitate as possible with a narrow crystal size distribution.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 21-29 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The desulphurization of synthesis gas with zinc ferrite was studied in a laboratory-scale fixed-bed reactor. Desulphurization efficiency of 97-99% was obtained. The inlet hydrogen sulphide concentration was about 2600 ppm. A flat breakthrough curve showed that diffusion through the sulphide layer controlled the rate of sulphidization. The degrees of utilization varied between 5 and 11%. Experimental data formed the basis of a kinetic evaluation with the fixed bed model and the unreacted core model. Rate constants, reaction orders, and effective diffusion constants were calculated. When chemical reaction controlled the rate, the order of reaction was between zero and unity. The rate of reaction increased with temperature. Effective diffusivities were of the order of 10-5 m2 s-1, increasing slightly in the temperature range between 500 and 600°C. The activation energy was determined as 54 kJ mol-1, which corresponds to an unexpectedly strong temperature dependence of the diffusion-controlled reaction. The low degrees of utilization, and also the strong temperature dependence, are explained by sintering of the sulphidized zinc ferrite.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 41-46 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The hydroxycarbonate of nickel and aluminium (Ni/ Al = 3) with a hydrotalcite-like structure is an outstanding precursor of the active component of supported nickel catalysts. Good mechanical strength and suitable nickel content of these catalysts, which are necessary for practical applications, can be achieved by mechanical mixing of this compound with an additional support. The catalyst prepared from a mixture of 56.5 wt-% of nickel-aluminium hydroxycarbonate and 43.5 wt-% of γ-alumina was proven to have a stable catalytic activity in the methanation reaction at 2 MPa and 800 K.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 34-40 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Catalytic dehydrogenation of methanol is a promising process of producing water-free formaldehyde. The present paper reviews research in this field. As effective catalysts mainly transition metal compounds as well as oxides and salts containing sodium have been reported. Several catalysts exhibit high activity and high selectivity, for formaldehyde at low conversions while further efforts have to be made to improve catalyst stability and selectivity at high conversions. Catalytic dehydrogenation of methanol to formaldehyde is compared with methanol oxidation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 27
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The separation of ethoxylated aliphatic amines from zinc containing effluents with macroporous polymeric adsorbents Wofatit EP 61, EP 62, Y 59, Y 77 and active carbons has been examined. The adsorption behaviour has been investigated as a function of temperature, time and concentration of Na2SO4, ZnSO4 and H2SO4. The macroporous polymers EP 61, Y 77 and Y 59 are capable of separating ethoxylated aliphatic amines from effluents of viscose fibre industry at higher temperatures and under weakly acidic conditions. In contrast to active carbon, inorganic components are not adsorbed on the investigated macroporous resins. Data obtained in a concentration range of 0 to 10 g of adsorbate per litre produced a Langmuir profile for adsorption of ethoxylated aliphatic amines by polymeric adsorbents.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 50-60 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Knowledge of transport processes is of considerable practical importance in the design and performance evaluation of packed bed reactor systems. Acquisition of the required information necessitates a realistic mathematical description of the system. In this study, numerical analysis is performed for forced convective non-Darcian, non-isothermal compressible flow and heat transfer in cylindrical packed beds. Local structural and transport properties are considered. The influence of compressional work as well as viscous dissipation on the thermal field is evaluated and a general criterion provided for assessing the effect of expansion.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 47-49 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The phrase “further remarks” in the title of this short paper is meant to imply that reactions and dimensionless groups are not only purely algebraic concepts, but definite numerical values can also be associated with them; in stoichiometry this evaluation may relate, for example, to the heat of reaction and, in dimensional analysis, to what is called a dimensionless number. On the basis of the evaluation concept, it will be shown that a counterpart of Hess' law in thermochemistry is valid in dimensional analysis.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 88-94 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Inertial deposition of aerosol droplets (diameter: 1-14 μm) on steel spheres (diameter: 3-9 mm) was investigated. Air velocity was varied between 7 and 28 m/s (corresponding sphere Reynolds numbers: 1400-17000). The impaction on single spheres as well as that on linear arrays of eight spheres was measured. Theoretical results, based on potential flow investigations were verified by single sphere experiments. Of special interest was the range of lower Stokes numbers, where the theoretically predicted limit of deposition cannot be verified. The experiments on sphere arrays were for the first time performed in the low Stokes number range. Deposition on the leading sphere, relative to that on the shielded spheres, exhibits a maximum in the high Stokes number range, but this changes drastically in the low Stokes number range. Here, maximum deposition can be found on the shielded spheres while the leading sphere shows a markedly lower deposition.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 73-80 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Due to induced turbulent interactions between particles to be separated and the scrubbing liquid present as droplets, very good collection efficiency down to submicron particle size can be achieved as shown by detailed studies [1]. Assumed are suitable flow conditions, a long residence time and a certain droplet size distribution or a special liquid dispersion system. As the name implies, the cyclone scrubber basically consists of a cyclone. This cyclone serves as a contact space in which the interaction between dust particles and scrubbing liquid droplets takes place, and as a droplet separator. Thus, under normal conditions, a water saturated but dust- and droplet-free gas stream leaves the cyclone. The droplets are generated by a pneumatic atomization nozzle, arranged at the cyclone inlet in the direction of flow. A complete theoretical description of the three-dimensional, three-phase, non-steady turbulent flow in the cyclone scrubber has not been possible up to now. The detailed experimental investigations presented in this work, and covering multiple parameters, led to physically based conclusions about the dominant interactions and separation mechanisms involved. Grade efficiencies which did not fall below 0.75, down to a particle size of 0.5 μm, could be measured by an optical particle counter. Collection efficiency of 99.2% was determined by gravimetric analysis of the dust load, according to VDI-guideline 2066, in the raw and clean gas sections of the dust load, according to VDI-guideline 2066, in the raw and clean gas sections of the cyclone scrubber.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 81-87 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Plasma arc welding processes are used in the off-shore industry for construction and maintenance of underwater structures and pipelines in a wet environment. At greater water depths the density of the plasma gas increases because of the greater hydrostatic pressure. This causes conductive heat losses to the wet environment to increase. To maintain the energy flux to the workpiece to be welded, the plasma arc has to burn in a local dry area with an inside pressure of 1 bar. This requirement can be fulfilled by a rotating cylinder with a liquid film flowing down the inner wall. The flow around the rotating cylinder is experimentally investigated. The rotating cylinder is placed above the work surface which is simulated by a flat plate. Because of the centrifugal forces of the rotating flow inside the gap between the lower end of the cylinder and the flat plate the water is forced out of the cylinder. The velocity distribution in the flow is measured by laser Doppler anemometry. The phase distribution in the two-phase flow in the gap is measured by local electrical probes. The static pressure inside the gaseous atmosphere is reduced in comparison to the hydrostatic pressure of the surrounding water. The pressure reduction is given by the void fraction, the phase distribution and the volume flow rates of both phases in the gap as well as by the speed of revolution and the design of the cylinder and the work surface. The influence of these parameters on heat transfer from the workpiece to the two-phase flow regime is also investigated.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 95-101 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The process of homogenization of liquids in a tall vessel equipped with a multiple impeller was studied. Up to four standard Rushton turbines and/or six pitched-blade turbines were used. The mixing time in the system was measured by the conductivity method. A continuous time history of the tracer concentration at several points in the system was recorded. The data were interpreted by means of an adapted cell model of the flow within the stirred vessel with several impellers based on the assumption of well mixed cells and intercellular flow of liquid. The liquid transfer flow rate between the cells, as a parameter of the model, was calculated from experimental data. A good agreement between the time dependence of concentration obtained experimentally and that calculated from theory was obtained. A direct relationship between the flow numbers between cells and those of impellers was established.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 108-111 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: It has been shown that, after a partial deactivation, γ-alumina (γ-Al2O3) is a good catalyst for selective methylation of 1,2-benzenediol in the temperature range of 260-310°C. The main products are the desired 3-methyl-1,2-benzenediol and 2-methoxyphenol, which may be converted in another step into 3-methyl-1,2-benzenediol, giving an overall selectivity for the desired products of 80 to 90%. The catechol forms a strongly chemisorbed surface species on γ-alumina and its steric adsorption model correlates with the kinetic data.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 112-118 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Kinetic studies as well as morphological and physico-chemical surface studies have been carried out on the deactivation of a palladium carrier catalyst for vinyl acetate synthesis in the ethylene gas phase process. The experiments cover concentration and temperature ranges of technical interest at a total pressure of 900 kPa. The deactivation rate depends on the temperature and the oxygen and acetic acid concentrations. The decline in activity is best described by a rate law of second order relative to the activity number. This behaviour is attributed to the observed aggregation of finely dispersed palladium. It can be concluded that palladium(II) acetate acts as a transport species in a chemically assisted sintering mechanism. At temperatures T ≤ 438 K the more advantageous final texture of the catalyst will only be formed on reaction.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 36
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A continuous production process has been developed up to pilot scale (300 l) for FDH production with the methylotrophic yeast Candida boidinii. A high cell mass specific FDH activity (50 U/g) is achieved by process computer controlled supply of pure methanol to operate the reactor at an optimum methanol concentration of 10 g/l. The maximum FDH spacetime yield achievable with this process control involves a residence time of 7 h. The FDH space-time yield (STY) and FDH concentration are a function of the oxygen transfer rate (OTR) of the fermenter (maximum STY = 255 U/(l h) at kLa = 870 l/h). For a reasonable compromise between high FDH space-time yield and high FDH concentration, an optimum residence time is adjustable by regulating the supply of nutrient salt solution in relation to the OTR of the fermenter. On a pilot scale (200 l continuously stirred tank reactor) roughly 4 million U of FDH were produced within 10 days at a residence time of 14.3 h. Isolation of intracellular FDH enzyme was performed using extraction with an aqueous two-phase system (PEG/K2HPO4). A technical product quality of 1.2 U/mg FDH was achieved without any chromatographic purification step.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994) 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 141-143 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A prototype “autocirculation”-type reactor has been designed and constructed at the N.I.O.C. Research Institute, Tehran and a mathematical model describing the concentration versus time profile subsequently developed. The model encompasses mass transfer considerations and kinetic studies of the regeneration reaction. For this purpose, the rate equation for iron complex oxidation, proposed by Japanese researchers, was modified and a new rate equation presented. This rate equation has been widely used in the above mentioned mathematical model. With this model, the vessel volume for a time-dependent H2S feed has been calculated for a “ZDDP” production unit.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 145-148 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In order to illustrate the use of CFD in providing an understanding of mixing processes, three examples, mixing in a pipe, homogenization with a static mixer and flow in a mixing vessel with a Rushton turbine, are discussed and compared with experimental results. Special attention is focussed on the resultant concentration distribution, which is closely linked to turbulent properties. A semi-empirical model is presented for a quantitative prediction of the initial turbulent conditions. Using special numerical techniques a mixing vessel with wall-separated baffles, which represents a problem generally regarded as beyond the capabilities of numerical analysis, can be simulated.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 358-363 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Cooling breakdown in highly exothermic reaction processes may lead to runaway. The sensitivity and the safety assessment of a batch process on cooling breakdown are studied. The dependence of the minimum cooling time and the maximum allowable time of cooling breakdown for safe operation on the process parameters is investigated.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994) 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 374-381 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the proposed combined sterilisation and concentration method, the original milk is first sterilised under conditions of continuous flow and after reaching the desired sterilisation temperature the product is concentrated by means of flash evaporation during subsequent cooling. Addition of stabilisers to maintain the thermal stability of the concentrate during sterilisation is not necessary in this process. The method presupposes that cooling with concentration is carried out under sterile conditions. This is technically quite feasible on use of multistage flash evaporation.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 195-200 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Shock tube pyrolysis of propane at temperatures between 1300 K and 2700 K at reflected shock pressures of 500 to 1500 kN/m2 has been investigated. The reaction is of 1st order with a rate constant K = 1.79 × 108 exp (-176.2 kJ/RT) s-1. The major reaction products were acetylene, ethylene and methane, while traces of propylene and ethane were only detected at temperatures below 1500 K. At higher temperatures, propane conversion to acetylene increased at the expense of the other products. Optimum conversions to ethylene and methane, in contrast to that to acetylene, were more sensitive to changes in temperature than to variations in reaction time. However, at reaction pressures above 550 kN/m2, extension of reaction time beyond 0.5 ms did not favour the formation of acetylene. A simple kinetic model which confirmed the experimental optimum product selectivity conditions is put forward.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 44
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This contribution presents a chemical reactor model of a circulating fluidized bed (CFB) which takes into account adsorption effects and provides a description of the vertical profiles of gas concentration in the riser. The oxidation of NO is used as an example of a heterogeneous catalytic reaction. Mass transfer between the gas phase and solid particles in the CFB was investigated at various temperatures and solids mass flow rates. The measurements show that the mass transfer coefficient decreases with increasing solids mass flux and that the CFB resembles a bubbling fluidized bed as regards gas-solid contacting.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994) 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 210-215 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The kinetics of the pseudohomogeneous liquid phase synthesis of a high molecular weight ester in a stirred tank reactor using cobalt chloride as catalyst has been studied at various temperatures, catalyst concentrations, and acid/alcohol molar ratios. A kinetic model has been determined that predicts the experimental results quite well.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 61-66 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper discusses the criteria for obtaining an improved performance of structured packing columns in gas-liquid contacting, by improving the liquid and gas distributors. A new liquid distributor design, specific for structured packing columns is presented. Experimental measurements which quantify the improvements attained by the new distributor are also presented. Furthermore, gas flow distribution requirements for structured packing columns are discussed. Three “case studies” indicative of the implementation of the proposed distributor concept in industrial columns are included. Case (a) CO2/MEA removal column, case (b) ammonia splitter and case (c) acid gas neutralization column.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994) 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 102-107 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The objective of this study was to determine the influence of viscosity on micromixing in turbulent flow. It was first necessary to find a suitable viscosity-raising additive. HEC (hydroxyethyl cellulose) proved to be better than previously studied additives [sorbitol and carboxymethylcellulose (CMC)]. In concentrations up to 1 wt-%, HEC solutions are almost Newtonian with viscosities independent of pH over the range 2 to 10. HEC had no effect on the reaction rate constants and the spectrophotometric analysis of the fast, competing reactions used - the diazo coupling between 1-naphthol and diazotized sulphanilic acid. The viscosity can then be raised by around an order of magnitude by adding less than 1 wt-% HEC to this reaction system.Diazo couplings were conducted in a 20 1 semi-batch tank reactor stirred by a Rushton turbine at two viscosity levels (0.9 and 6.2 mPa s). Long feed times ensured that micromixing was controlling. More bisazo dye was formed in the more viscous solution, all other conditions being unchanged, indicating more intense segregation and slower micromixing.This was also shown by visualizing the extent of neutralisation zones, with more spreading and slower micromixing being observed in viscous solution. Higher turbine speeds reduced this spreading. One feed point near and one far from the turbine were employed: the strong inhomogeneity of the turbulence led to smaller amounts of bisazo dye when the feed was added to the turbine suction, irrespective of the viscosity. All results agreed with the trends predicted by the engulfment model of micromixing. Its simplest form assigns an average energy dissipation rate to the reaction zone: the values obtained are of similar magnitude to those measured by physical techniques and were related to the spreading of the reaction zone.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 50
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A batch reactor directly combined with an ultrahigh vacuum apparatus, which is equipped with facilities for catalyst preparation and Auger electron spectroscopy, was used to answer some questions which had arisen in recent studies concerning carbon dioxide hydrogenation on pure metallic and supported Co catalysts. Both oxygen incorporated during oxidation/reduction cycles and carbon deposited when CO2 is hydrogenated penetrate deep into the bulk. This kind of carbon can easily be hydrogenated. CO strongly hinders the reduction of the oxidized Co surface in the H2/CO2 reaction mixture (4 : 1). CO hydrogenation is favoured over CO2 hydrogenation and leads to a higher percentage of C2 to C4 hydrocarbons as compared with CH4 formation.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An airlift reactor with inverse internal loop (annulus sparged) is investigated with regard to liquid velocity and dispersion coefficient for the purpose of reactor design. To distinguish between the influence of the individual parts of the reactor (downcomer, riser, bottom) on the liquid velocity and mixing, several draft tubes with different geometries and draft tube bottom clearances are successively installed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 397-400 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The extraction of zinc chloride by Amberlite LA-2, a long chain secondary alkylamine, dissolved in Shellsol K, a naphthenic solvent, has been studied at room temperature. Isodecanol was used as modifier. The aqueous phases were chloride solutions of Zn(II) and Fe(II) in the concentration range commonly encountered in pickling baths, viz. about 1 and 1.5 mol/l, respectively. The ionic strength was kept constant at 4 mol/l in all experiments. Measurement of the distribution equilibrium of zinc chloride was carried out over wide concentration ranges of amine, zinc chloride, free chloride and isodecanol. It was assumed that the zinc chloride was extracted according to the following reaction \documentclass{article}\pagestyle{empty}\begin{document}$${\rm ZnCl}_{2,{\rm aq}} + 2{\rm AHCl}_{2,{\rm org}} \leftrightarrow ({\rm AH})_2 {\rm ZnCl}_{4,{\rm org}} $$\end{document}On the basis of this reaction, an easy to use model was developed to describe the extraction behaviour of Zn in typical pickling baths. Prediction and optimization of a solvent extraction plant performance under changing industrial feed conditions is then possible. This model takes account of the influence of isodecanol used as modifier.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 430-434 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 54
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new method for applying reaction calorimetry to stirred tank reactors with variable heat transfer is presented. Sinusoidal temperature oscillations are induced by an electrical heater placed either in the reactor or in the jacket in order to decouple the chemical heat production from the variable heat transfer during reaction. Multiplication of the reactor heat balance by periodic functions and integration yields the overall heat transfer. Temperature oscillation calorimetry was successfully applied to the free radical polymerization of methyl methacrylate in ethyl acetate which shows a strong decrease in heat transfer.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 422-429 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Affinity chromatography (biospecific adsorption) relies on specific interactions of biological molecules such as enzymes, antigens, antibodies, and proteins. The process consists of three steps: adsorption, washing, and elution. A mathematical model including convection, diffusion, and reversible reaction is formulated to analyse the breakthrough behaviour of the solute. A moving finite element orthogonal collocation method is applied with respect to the space variables of the governing partial differential equations of the model to evaluate the breakthrough of the solute. Danckwerts' boundary conditions are considered for the column. The validity of the numerical scheme is checked by comparison with an analytical solution for a simplified model. The results obtained from model simulation show that the breakthrough time of the solute is significantly influenced by the axial dispersion coefficient, solute concentration, ligand content, reaction kinetics, particle porosity, particle size, and flow rate. Solute recovery and bed utilisation efficiencies are evaluated for different values of the above parameters.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 249-254 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An automatic apparatus has been developed and set up for the study of drop-interface coalescence. Most other studies have concentrated on events when the drop arrives at the interface with its terminal velocity. In our case, the drop is maintained fixed at the tip of a needle, and the interface is moved towards the drop at a controlled speed. The coalescence times are measured by means of a vectorial video camera focused on the drop. Several times are measured by means of a vectorial video camera focused on the drop. Several parameters have been investigated, such as the drop diameter, the relative drop-interface velocity, the phase system, the presence and the direction of mass transfer.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 255-268 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper describes the development of a dynamic simulation model for stirred tank batch or semi-batch chemical reactors fitted with an alternative heating-cooling system. Heat and mass balances are established for the reactor and its jacket. Since the general purpose of our research is the thermal control of these reactors, special attention is devoted to the behaviour of the heating-cooling system. In this article, we are particularly concerned with an alternative system, i.e. different fluids at a constant temperature can be alternatively delivered to the jacket. The computer simulation programme is flexible, enabling simulation of a batch or semi-batch reaction vessel, ranging from a laboratory pilot plant to a full-scale production plant. A control algorithm is included which allows reactor operation with open or closed-loop temperature control. To demonstrate the good performance of the simulation model, experimental results are presented for both a pilot plant and an industrial reactor.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 273-279 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A rigorous one-dimensional heterogeneous model is developed for a secondary reformer in an ammonia plant with special emphasis on the catalyst particle models. These are based on the effective diffusivity model and the Stefan-Maxwell model in the catalyst pore and the film around the catalyst particle. The performance of these four models is evaluated for the data collected from a commercial reformer in the complete operating range and recommendations are made regarding the use of appropriate particle models. The models for the catalyst particle show considerable deviations at the particle level but the reformer simulations produce almost identical results at the global level for all the four particle models. The need for a rigorous treatment of interphase resistance to mass transfer has been clearly demonstrated by comparison of the present model with the model of Singh and Saraf.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 59
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper presents a new procedure for optimization of continuous mixed suspensionmixed product removal (MSMPR) crystallizing systems. Owing to the difficulties of theoretical modelling, simulation of the MSMPR crystallization process is based on the use of artificial neural networks (ANN). The optimization criterion is a compound objective function corresponding to an intended mean crystal size dimension and a minimal dispersion. The presence of multiple local minima has called for investigation by several optimization techniques. Ultimately, Luus' and Jaakola's random adaptive method proved to be most effective. The results obtained lend support to the general procedure proposed.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 280-284 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The classical two-film model for mass transfer between two fluid phases can only be used to describe the steady state mass transfer mechanism. Both the penetration and the film-penetration model are also valid solely when only one diffusion boundary layer exists at the interface between the phases. With a view to surmounting the limitations of the above models a new model has been developed for the mass transfer between two fluid phases with two diffusion boundary layers at the interface. The new model is based on the two-film concept and the Danckwerts distribution function, and is also able to simulate the unsteady state mass transfer mechanism between two fluid phases with two different boundary layers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 291-300 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Biotechnological production processes for low-molecular bulk chemicals can only compete with their petrochemical counterparts on using inexpensive raw materials, e.g., agricultural by-products or wastes, otherwise requiring disposal. The upgrading of by-products/wastes of potato starch production and the use of potato protein liquor and potato pulp for the production of bulk chemicals were investigated. It transpired that the economy of these processes depends on the waste disposal costs of the upgrading processes. In addition, it is shown that specialty chemicals can be produced economically from wastes. However, since they are produced in a large quantities, the upgraded product cannot be put on the market without ruining existing prices.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 323-324 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 313-322 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Gas phase conversions and product selectivities predicted by the single-bubble-class and modified two-bubble-class models of bubble column reactors are compared for a multistep gas-liquid reaction involving series/parallel steps. A situation is considered where the first reaction step is fast and occurs in the interfacial region while the other reaction steps are slow and occur only in the liquid bulk. Equivalent hydrodynamic and transport parameters provide a common basis for the comparison. The differences in the gas phase conversions predicted by these models are insignificant. However, the two models predict very different values of selectivities for the intermediate products. This analysis enables us to judge the range of applicability of the single-bubble-class model in design and scale-up of bubble column reactors.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 64
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The Cocurrent Downflow Contactor (CDC) has been developed as a mass transfer and reactor device, with and without addition of tangential (swirl) flow, giving gas hold-up (Eg) values of 0.5-0.75, interfacial areas in the range 1000-6000 m2m-3 liquid and kLa values in the range of 0.15-1.55 s-1 for absorption using the O2/H2O system. It has been studied as a catalytic slurry reactor for the hydrogenation of (i) itaconic acid and (ii) triglycerides catalysed by Pd and Ni catalysts. The reactions were observed to be largely surface-reaction rate controlled, due to the very efficient mass transfer (kLa up to 11.75 s-1 under reaction conditions) and application of swirl flow-enhanced reaction rates. The CDC has recently been found to be capable of operating as a fixed bed reactor, thus eliminating a downstream catalyst separation problem (therefore more cost effective), and is superior in its mass transfer characteristics to other known devices. Scale-up can be undertaken without loss of performance efficiency.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 65
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The behaviour of an adiabatic packed bed reactor with periodic flow reversal has been studied by means of model calculations. A heterogeneous model as well as a pseudo-homogeneous model have been developed. It is shown that a high degree of conversion can be obtained in an autothermal process even with very low adiabatic temperature rises of some 10 to 20 K. The reactor is insensitive to fluctuations in inlet concentrations and in through-put. Short-cut methods proposed in the literature for calculating the plateau temperature in the pseudo-steady state are studied. The so called countercurrent-flow reactor approach showed reasonable agreement with the plateau temperature obtained by dynamic calculations with the full reactor model.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 227-234 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Concentration profiles are measured during the mixing process of carbon dioxide and air, which were injected into the rectangular cross section of a duct. The volume flow rates of both components differ considerably. The non-stationary and three-dimensional concentration fields are measured by optical tomography using holographic interferometry as the measuring principle. Projection data from four different viewing angles are used for tomographic reconstruction by the ART method. Pressure losses due to mixing processes are also measured. Results are presented for different angles of injection and different ratios of momentum flow rate for single and multiple jets of carbon dioxide which were injected into the carrier gas stream of air.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemical Engineering & Technology - CET 17 (1994), S. 235-241 
    ISSN: 0930-7516
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A spray dryer simulation program is described. It is based on the known conservation laws and permits determination of temperature and moisture profiles and droplet trajectories inside spray dryers. An industrial spray dryer used in the manufacture of detergents serves as an example to demonstrate the applicability of the program; this approach required prior experimental determination of the flow field and an axial temperature profile. On the basis of a rough estimate of the drying rate in the spray dryer, good agreement was observed between experiment and simulation.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 84-90 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Real process fluids such as emulsions and suspensions are optically absordent as well as inhomogeneous. Using phase-Doppler anemometry (PDA)for investigating the spray cone, the inhomogeneites have led to incomprehensible size distributions. In this paper, solutions of instant coffee and condensed milk, representing typical process fluids, were chosen for PDA measurements in comparison with PDA applied to water droplets with the same atomization process in order to clarify the reasons for the measured broad size distributions. By applying PDA to monodisperse droplets and to “monodisperse” and real polydisperse sprays consisting of such fluids, it is shown how the measured size distributions arise, Based on this knowledge, the real size distributions are reconstructed and compared with that of water atomization. Therefore, PDA can in future also be applied to real process fluids, and process control, based on the information provided by PDA, is coming nearer.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 107-113 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This paper describes the pulse displacement technique(PDT) to simultaneously measure particle size and velocity in applications characterized by a large size range and high particle concentration. PDT is based on the detection of scattered refraction and reflection pulses which sweep past a detector at different times as a particle traverses a narrow probe volume. Basic analytical relationships are presented which allow the calculation of the spatial and temporal widths and separations of the reflection and refraction pulse as a function of particle diameter and velocity. Two implementations of PDT are discussed using one or two receivers with two laser sheets having the same or different wavelengths. This paper also discusses several methods to measure particle velocity with PDT, discusses the limitations associated with signal broadening in practical systems, and briefly presents experimental results which show that the temporal separation between the refraction and reflection and reflection pulse maxima is independent of collecting lens f-number from f/3 to f/20 for particle sizes ranging from 250 to 2000 μm.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 121-126 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This study deals with the size measurement of non-spherical particles by the laser diffraction technique. Size analyses of three sets of identical metallic bodies (cubes, tablets and cylinders) were performed by means of a Malvern 2600 instrument. The results prove that under the operating conditions chosen and in the case of anisometric objects, the mean total surface area is not measurable either because the Malvern software, strictly valid for spheres, is not applicable to such particles or because the particles adopt preferential orientations in the measurement cell. Further, a way of processing diffraction data is proposed in order to determine two characteristic dimensions of identical anisometric particles. It is based on the measurement of the minimum and maximum projected surface areas of the particles. The experimental results obtained with our particles show the procedure to be reliable.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 145-149 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Laser light scattering (LLS), especially dynamic laser light scattering (DLS), also known as photon correlation spectroscopy (PCS), is a well established method for particle size distribution analysis. It usually involves a Laplace inversion of the field autocorrelation function. However, the resolution is limited because of the ill-conditioned nature of this Laplace inversion. No unique solution exists when noise is present on the data. In contrast with this ill-conditioned nature, the angular dependence of scattered (static) intensities is precisely not ill-conditioned, which allows the resolution of the ill-conditioned inversion of DLS data to be improved. In order to characterize samples with more complicated size distributions, an intensityconstrained multi-angle PCS data analysis program has been developed, which is an alternative way of normalizing the field correlation function to that reported by Cummins and Staples [12]. In this program, the field autocorrelation function is normalized to the scattering intensity by using a predetermined coherent factor at each angle, which provides an additional constraint on the Laplace inversion of multi-angle PCS data analysis. The alternative analysis improves the resolution of PCS and provides a more reliable particle size distribution than single-angle data analysis. Both simulated and measured LLS data are used to illustrate its application, resolution and limitations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 7-21 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Theoretical and practical limits on the applicability of PDA are established, using generalized theoretical formulations of various physical processes governing the operation of a phase Doppler system. Furthermore, several innovative solutions are introduced to prevent the commonly occuring problems of PDA, such as Gaussian profile effect, non-monotonic response and 2π-ambiguity. Generalized formulations have also enabled new applications, such as sizing of submicron particles, particle material recognition, measurements with non-standard geometries. Selected results of measurements in particulate flows, using innovative PDA systems, are also presented.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Phase-Doppler anemometry (PDA) is applied for particle size, velocity and concentration measurements in two-phase or multi-phase flows of ever increasing complexity. For accurate measurements the experimenter must be provided with software and hardware which permit an optimal layout of the PDA optics for a given application, reliable detection of signals over a wide particle diameter range, accurate determination of particle concentration and precise discrimination between particles of different composition. Recent work at LSTM, Erlangen, has been directed to developing a complete PDA package for the above purposes. Progress in this direction is summarized in this paper.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 73-83 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This review of the recent developments in the phase Doppler method provides information on the advances made to the method and delineates some potential error sources. Methods used to eliminate these potential error sources are also discussed. It is shown through comparison to the Lorenz-Mie theory and the GLMT that the geometrical optics theory offers a reliable and efficient computational tool for the analysis of the light scattering with the phase Doppler method. The geometrical optics theory was then used to optimize the measurement parameters in the system designs and a significant reduction in the measurement uncertainty was realized. Limitations on the particle concentrations in which the instrument will operate reliably are also addressed. A brief discussion of the instrumentation and, in particular, the signal processing is presented. The advantages in using the Fourier transform approach are discussed. As a demonstration of the capabilities of the instrument, several performance tests were reviewed and examples of the application to spray combustion and turbulent dispersion of particles are given.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 91-100 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The results of comparative measurements of three different phase-Doppler systems applied to a steady-state water spray are discussed. The three receiving systems, i. e. DANTEC 57X receiving optics with covariance processor, an AEROMETRICS fibre-based receiver with DSA processor and standard INVENT phase-Doppler extension, were used with a 2-D fibre-optics-based transmitting system. A constant scattering angle of 70° was chosen, which is near the Brewster angle for water. Measurements were taken in the spray cone of hollow-cone pressure atomizer at two different axial distances from the nozzle. Local size distributions, size/velocity correlations and the mean diameters D10 and D32 were compared. The results indicate very good agreement between the different systems, especially with respect to the mean diameters. Larger scatter of the results occurs for the measured volume flow rates, but the calculated mean volume flow rates coincide fairly well with the nominal flow rate of the atomizer.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 222-226 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The breakup of suspended, agglomerated submicron particles was studied by exposing the aerosol to weak shock waves of varying strength under conditions 400 ms-1≤v≤880 ms-1. A newly developed laser light-scattering diagnostic employing a top hat laser profile was used to size the particles passing through a very small scattering volume. By Comparing the optically measured particle size in front of and behind shock waves, the breakup of agglomerated particles could be clearly identified. The experiments indicate that the aerodynamic forces behind an incident shock overcome the particle binding force resulting in disintegration of the submicron agglomerates. The results are presented in form of a modified Weber number.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 241-249 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A laser-based method was developed for the simultaneous and quantitative imaging of drop and vapour clouds in an evaporating fuel spray. The method was based on extinction of two wavelengths, that is, ultraviolet and visible laser light through the fuel spray due to absorption by the vapour and scattering by the drops. α-Methylnaphthalene was selected as an injection fuel, since it absorbs the ultraviolet laser light but does not absorb the visible laser light. Subtraction of the transmissivity of the visible laser light from that of the ultraviolet laser light made it possible to image the distribution of the vapour cloud in the evaporating fuel spray. The distribution of the drop cloud is imaged by the transmissivity of the visible laser light. The method was applied to the fuel spray injected from a nozzle of a direct injection diesel engine into high-pressure and high-temperature nitrogen gas in a bomb.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 258-265 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A light scattering method has been devised to discriminates between coal and fly ash and measure particle size. Sizing was performed by the measurement of forward scattered intensity, and discrimination was displayed by the ratio of the intensities of crossed to parallel polarisations at a scattering angle of 160°. The technique has been applied to a study of coal combustion in a variable length drop tube furnace. It has been demonstrated that the development of the size distribution can be followed as a function of residence time. Further, it is indicated that there is a simple correlation between the polarisation ratio and the carbon content of the ash. This leads to the possibility of monitoring combustion efficiency in industrial furnaces.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 284-290 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The quality of particulate mixtures influences strongly the efficiency of downstream process steps. The design or optimization of mixing processes requires fast and accurate methods for determining mixture quality. This paper describes an optical method for the in-line concentration measurement of the key (tracer) component in particulate mixtures with fiber optical probes. Small fluctuations of tracer concentration equivalent to a low concentration variance represent a high degree of mixing. Monochromatic light penetrates via fiber optical probes into a powder sample. A photometer measures the intensity of the diffuse reflected light. If the tracer differs in colour from the other components of the mixture its concentration can be determined. Three types of fiber optical probes were tested. For calibration two series of mixed samples covering a broad concentration range were prepared, one consisting of white Al(OH)3 and dark SiC and the other of Al(OH)3 and a much finer green pigment. The calibration graphs are described by the Kubelka-Munk theory. The influence of changes in particle size on the signals is reduced by choosing a probe with an angled arrangement of the fibers. The sample mass of the probes is estimated to ca. 0.01 g, based on comparison with random mixtures at different tracer concentrations. In-line measurements provide extensive data sets which allow advanced statistical intepretations of mixing processes.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 309-314 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The total light scattering method for particle size measurement has a series of outstanding features, e.g. very simple instrumental arrangement, no serious requirements for its optical, photodetecting and electronic systems and its ease of use. Nevertheless, some problems still remain unsolved which should be dealt with to improve its further applications. An improvement has been made in this work. Comprehensive theoretical studies showed that this method is applicable to particle size analysis in the range 0.1-10 μm, i.e. for those particles whose diameter lies between the lower limit of the diffraction method and the upper limit of photon correlation spectroscopic (PCS) technique. Experimental studies with different monodisperse polystyrene latex spheres as standard reference material give good agreement with their nominal values.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 6-6 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 359-366 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A log-normal model, based on the extended SIMPLER-algorithm utilizing the Modal Aerosol Dynamics Modelling Technique, and a sectional model are compared for Brownian coagulation in the transition regime. The models are in good agreement with respect to the calculated particle size distribution moments. Applying the log-normal model a simple coagulation model consisting of a closed set of five equations is developed that does not require the solution of ordinary diferential equations.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 156-158 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experiments are described in which particle image velocimetry (PIV) is applied to the measurement of liquid droplets in a spray jet. The two velocity components in planes formed by the light sheet originating from a double-pulsed ruby laser are determined. The PIV records are evaluated with the method of Young's fringes. It is shown that this procedure allows the simultaneous measurement of the droplet size within a certain size range.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 159-165 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A commercial Electrical Aerosol Analyzer (EAA, TSI Inc. model 3030) was calibrated experimentally at three subambient pressures (i. e., 0.901, 0.878, and 0.853 atm). Each calibration resulted in a 19 × 11 response matrix and a size dependent sensitivity curve \documentclass{article}\pagestyle{empty}\begin{document}$ \left({\frac{{pA}}{{{\# \mathord{\left/ {\vphantom {\# {cm^3}}} \right. \kern-\nulldelimiterspace} {cm^3}}}}} \right) $\end{document}. The results of the calibration were incorporated into a data reduction computer program for size distribution inversion. The accuracy of the calibration was tested by measuring the size distribution of a NaCl polydisperse aerosol at the three subambient pressures. All the tests gave good agreement in the inverted mean geometric diameter and geometric standard deviation of the aerosol number size distribution.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 166-171 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Although common atomizing systems efficiently produce sprays, a range of droplet sizes is generally obtained and the distribution is often difficult to control in terms of liquid or gaseous flow rates. It is shown that an alternative system, based on ultrasonic surface instabilities, is well suited for experimental applications where all parameters have to be controlled. Technological aspects of ultrasonic atomization are described and the droplet spray produced by an ultrasonic atomizer is characterized experimentally.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 183-188 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: When an optical beam is incident on particles that are randomly distributed, and if the fractional volume is small, single scattering theory is adequate to explain the scattering characteristics of the medium. However, when the fractional volume is increased, multiple scattering effects cannot be ignored. This paper reviews the fundamental theories of multiple scattering including radiative transfer and diffusion theories. Also included are recent studies on polarization effects, localization, enhanced backscattering, resonant localization, pulse scattering and scattering in dense media.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994) 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 275-283 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This presentation is part of a fundamental investigation into the influence of structural characteristics on particle collection in fibrous filters. The collection on single fibres has been experimentally determined, whereby different fibre configurations were set. For this purpose, particle fluxes upstream and downstream of the fibres were measured simultaneously using an optical particle counter which operates with two purely optically delineated measuring volumes and two detectors. The experimental results are compared with published values.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 320-326 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Using a monodisperse PMMA dispersion, it was shown that light reflection at the sample cuvette walls may greatly influence the results of both static (SLS) and dynamic (DLS) light scattering experiments. Considering SLS, this reflection phenomenon mostly causes an overestimation of the scattered intensity at high scattering angles, which may give rise to the emergence of an additional, artificial peak in the lower region of the particle size distribution. On the other hand, the influcence of reflection on DLS measurements was shown to be particularly important in the upper region of the particle size distribution. The experimentally observed phenomena were explained from the basic principles of both particle sizing methods. Finally, it was shown that the disturbing effect of reflection could be avoided by modifying either the hardware or the software of the static and dynamic light scattering technique.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 351-351 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 398-402 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The three-dimensional particle size and shape of mechanically delaminated talc thin platelets were determined by combining two different methods. The plate diameter was determined by microscopy with the aid of an image analyser and the thickness from the X-ray crystallite size perpendicular to the basal plane. The net line broadening of the X-ray diffraction peak, necessary for the determination of X-ray crystallite size, was evaluated by electron microscopy. In order to correct X-ray diffractometry for instrumental broadening, the platelet thickness of a representative specimen was obtained directly using a transmission electron microscope coupled with a laborious slice technique with an ultramicrotome.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 5-5 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 22-34 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Many optical sizing techniques rely on particle/laser interactions. The classical Lorenz-Mie theory describing sphere/plane wave interactions is therefore misleading when designing instruments and processing data when the particle size is not small enough with respect to beam diameters. In such cases the use of the generalized Lorenz-Mie theory is required. After summarizing essential features of the generalized Lorenz-Mie theory for sphere/arbitray wave interactions, this paper describes applications of the theory with some emphasis on the analysis of phase-Doppler anemometers.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 182-182 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 194-199 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Forward light scattering is a well established technique for measuring particle size distributions. The light intensity fluctuations which can be observed in the diffraction plane of the instrument can be used to stabilize the inversion process [1]. Particle shape information is also present in these fluctuations. It is shown that an azimuthal-type of detector can be used to extract this information from the statistical correlations of the detector signals.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 212-221 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: So far, the evaluation of extinction measurements has mostly relied on Bouguer-Lambert-Beer's law (BLBL), even though BLBL is known to be valid in the limit of low concentrations only. With higher particle concentrations, particle-particle interactions such as multiple scattering, dependent scattering and steric interactions can lead to important deviations from BLBL. In a discussion of the various interaction mechanisms, steric interactions are shown to be dominating in a wide and practically important range of parameters. For the theoretical description of steric interactions, different complementary models are introduced, including a statistical model, a layer model and a numerical simulation model. The various approaches coincide to yield a simple extinction equation in two versions, applying to the regimes of Fraunhofer diffraction and straight ray propagation, respectively. In any case, BLBL is found as the low concentration limit of the extinction equation. All considerations are restricted, so far, to the case of monodisperse spherical particles.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 235-240 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The diffraction patterns of static particles deviate from those of dynamic particles of the same distribution characteristics. Use of diffraction solutions based on independent scattering to analyse such diffraction patterns leads to a narrower size distribution biased towards the smaller sizes. A 2-D coherent diffraction model using an inter-particle relation PDF function is developed. The model clearly demonstrates the terms due to the individual particle diffraction and the terms contributed by the inter-particle correlation, i.e. the coherent effects. The deviation of the static particle diffraction pattern from that of the dynamic particles can be well predicted. The results of this study provide a general solution for utilizing the forward diffraction technique in static particle measurement. One of the important applications of the new model is in the development of a diffraction reference reticle used for diffraction-based particle sizing instruments verification.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994) 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 299-308 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The theory of interaction between a shaped beam and an infinite cylinder arbitrarily located in it is presented. The same approach as for the generalized Lorenz-Mie theory is first used. In particular, variable separability is assumed in solving the wave equation. The special case of Gaussian beams, however, implies that, unexpectedly, a special class of non-separable scalar potentials is required for some kinds of beams.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Particle and Particle Systems Characterization 11 (1994), S. 327-338 
    ISSN: 0934-0866
    Keywords: Chemistry ; Industrial Chemistry and Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Measurements of particle size distributions in multi-phase flows with a phase-Doppler anemometer yield incorrect results if polydisperse particles are investigated. For weighting biased size distributions, different in situ methods, requiring the size of the detection area, are known, but all of these weighting procedures are restricted to very small measuring volumes if off-axis instrument configurations are considered. Moreover, the weighting functions have some disadvantages in the case of poor statistics in single size classes or the results are not suitable for determining the size of the detection area for particles which are larger than the beam waist.Therefore, the intention in this work was to measure the size of the detection area for different kinds of monodisperse particles, different instrument configurations and varied instrument sensitivities experimentally and to develop an improved weighting procedure that copes with the above difficulties. The application of the results obtained from the investigations with monodisperse particles to measured particle size distributions and volume flux densities of polydisperse water droplets in a spray cone of an atomizer confirms the applicability of this weighting procedure. It is still restricted to directed flows, perpendicular to the fringes.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...