Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Adsorption of oxygen, nitrogen, and argon on 5A molecular sieve (1985)
    s.l. : American Chemical Society
    Journal of chemical & engineering data 30 (1985), S. 66-70 
    Details
    ISSN: 1520-5134
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/je00039a022
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Development of a Catalytic Candle Filter for One-Step Tar and Particle Removal in Biomass Gasification Gas (2003)
    Berkeley, Calif. : Berkeley Electronic Press (now: De Gruyter)
    International journal of chemical reactor engineering 1.2003, 1, A29 
    Details
    ISSN: 1542-6580
    Source: Berkeley Electronic Press Academic Journals
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Renewable energy generation from biomass (e.g. wood, agricultural wastes) by gasification is attractive because it can be used for efficient energy production on both small and large scale. Unfortunately, biomass gasification gas contains unwanted impurities, such as condensable tars and ash particles that need to be removed to avoid damaging of the downstream equipment.This work reports on the performance of a novel catalytic candle filter for the integrated high temperature removal of tars and particles from the biomass gasification gas. The catalytic candle filters that are under development are alumina ceramic filters that contain a suitable nickel-based tar cracking catalyst in their pores. This not only avoids mass transfer limitations occurring in packed beds of such catalysts, but also yields a reduced investment cost for the cleanup step.Different nickel-based catalysts have been developed and impregnated in the pores of the alumina support. Nickel is efficient for tar removal, but is sensitive to sulfur poisoning by the biomass gasification gas that typically contains 20-200 ppm H2S. To enhance the resistance to sulfur poisoning CaO or MgO was added to the nickel and also the number of active nickel sites was increased by the deposition of a highly dispersed secondary alumina layer in the large pores of the primary support.Small-scale porous alumina filter discs were tested on their sulfur poisoning resistance under lab conditions using a simulated biomass gasification gas containing benzene and naphthalene as model compounds. At typical conditions, such as a filtration velocity of 2.5 cm/s and a H2S-content of 100 ppm, naphthalene conversions of 99.89% were obtained with a Ni/MgO-activated filter disc with increased surface of the support.
    Type of Medium: Electronic Resource
    URL: http://www.bepress.com/ijcre/vol1/A29
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Alkylation of Bromobenzene with Allyl Acetate on Zeolite H-USY: Catalytic Testing and Reaction Modeling (2005)
    Berkeley, Calif. : Berkeley Electronic Press (now: De Gruyter)
    International journal of chemical reactor engineering 3.2005, 1, A23 
    Details
    ISSN: 1542-6580
    Source: Berkeley Electronic Press Academic Journals
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: The alkylation of bromobenzene with allyl acetate on zeolite H-USY (Si/Al 30) was studied in liquid phase conditions, at 150 °C. Reactions were performed at different space velocities (LHSV = 60, 120, 240 and 480 h-1) in tubular plug flow reactors using a high-throughput frontal analysis setup. Besides the desired alkylation products, cis-propenyl bromobenzene (cis-PBB) and trans-propenyl bromobenzene (trans-PBB) and a dialkylated product, light and heavy side products were formed. Polymerization reactions starting from allyl acetate lead to blocking of the zeolite pores, and result in catalyst deactivation. Based on the experimental data, several molecular kinetic models were proposed, and implemented in a reactor model, accounting for axial dispersion, mass transfer into the catalyst crystals, competitive adsorption effects and catalyst deactivation. Model discrimination revealed the underlying reaction mechanisms.
    Type of Medium: Electronic Resource
    URL: http://www.bepress.com/ijcre/vol3/A23
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Adsorption Competition Effects in Hydroconversion of Alkane Mixtures on Zeolites (2003)
    Berkeley, Calif. : Berkeley Electronic Press (now: De Gruyter)
    International journal of chemical reactor engineering 1.2003, 1, A36 
    Details
    ISSN: 1542-6580
    Source: Berkeley Electronic Press Academic Journals
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: In the present work, molecular competition effects in the hydroconversion of alkane mixtures in vapor and liquid phase were studied. The influence of the pore size was investigated by performing catalytic experiments with equimolar heptane/nonane mixtures on a series of bifunctional zeolite catalysts (Pt/H-Y, Pt/H-USY, Pt/H-Beta, Pt/H-MCM-22). Vapor phase catalytic experiments were performed at a total pressure of 4.5 bar, while a total pressure of 100 bar was applied in the liquid phase experiments. The experimental results were analyzed using a lumped adsorption-reaction model. In vapor phase, the longest chain is preferentially converted on all studied catalysts. In liquid phase, the differences in conversion rate were less pronounced. On Pt/H-MCM-22, with active pockets on the surface, and Pt/H-USY having large mesopores, the competition between short and long alkanes in liquid phase reflect the intrinsic reactivities of the reacting molecules. In zeolites with smaller pores (Pt/H-Y, Pt/H-Beta), an inversion of the reactivity order of alkanes of different chain length was observed when increasing the pressure from 4.5 bar and vapor phase to 100 bar and liquid phase. The inversion of apparent reactivity orders is due to changes in physisorption at high pressure, favoring uptake of the smallest molecules.
    Type of Medium: Electronic Resource
    URL: http://www.bepress.com/ijcre/vol1/A36
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Effectiveness factor calculation for immobilised growing cell systems (1994)
    Springer
    Biotechnology techniques 8 (1994), S. 695-700 
    Details
    ISSN: 1573-6784
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary Gel immobilised living cell systems represent a special form of heterogeneous catalysis. Due to mass transfer limitations on substrate delivery and product removal, time-dependent spatial variations in growth rate and biomass densities are created. A dynamic mathematical model has been developed which was used to simulate the start-up dynamics of growing yeast cells in calcium alginate beads. By coupling the transient model with the effectiveness factor calculation, the “dynamic effectiveness factor” could be calculated. The influence of the bead radius and the initial biomass concentration on the dynamic effectiveness factor have been investigated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00151471
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Adsorption of normal and branched paraffins in faujasite zeolites NaY, HY, Pt/NaY and USY (1997)
    Springer
    Adsorption 3 (1997), S. 251-265 
    Details
    ISSN: 1572-8757
    Keywords: multicomponent equilibrium ; zeolite ; chromatography ; paraffins ; heat of adsorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Physics , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The effect of chain length and branching of paraffins (from C6 to C12) on adsorption and diffusion in zeolites NaY, Pt/NaY, HY and USY has been investigated using the chromatographic method at 275–400°C. The Henry constants of the paraffins increase exponentially with the chain length (with a factor two per extra carbon group), the heats of adsorption increase with circa 7 kJ/mol per extra carbon group. Multicomponent sorption experiments reveal that longer chains are adsorbed preferentially over shorter chains, even at higher loadings. The multicomponent adsorption can be reasonably well described by an extended Langmuir adsorption isotherm, in which the stronger adsorption of the longer chains is reflected by their higher Henry constants. The molecular shape and zeolite type within this FAU group has only a small influence on the adsorption properties. Mass transfer in the pellets as used in catalytic conditions seems to be limited by macropore diffusion, rather than by micropore diffusion, which cannot be measured with the chromatographic method. Increasing the Si/Al-ratio of the zeolite reduces the adsorption capacity, but does not influence the relative adsorption properties.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01653628
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Modeling the exponential growth of filamentous fungi during batch cultivation (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 60 (1998), S. 169-179 
    Details
    ISSN: 0006-3592
    Keywords: mathematical model ; morphology ; pellet ; filamentous fungus ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In certain conditions, filamentous fungi are observed to grow exponentially during batch submerged growth. It is shown for three cases, with simple mechanistic models, that an exponential growth assumption is reasonable. The basis of these models is the identification of a growth unit, and a mechanism for its doubling with a constant generation time. The importance of the variation of morphological properties within populations is demonstrated by the comparison of computer simulations of simplified models using average values and either experimental data or computer simulations of detailed stochastic models. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 60: 169-179, 1998.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 8
    Electronic Resource
    Electronic Resource
    Simulation of growth of a filamentous fungus in 3 dimensions (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 53 (1997), S. 139-150 
    Details
    ISSN: 0006-3592
    Keywords: filamentous fungus ; tridimensional structure ; fractal dimension ; spore aggregates ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The tridimensional growth of a filamentous fungus was simulated, based on a model for the evolution of the microscopic morphology of Trichoderma reesei. When supplemented with a spatial representation of growth, the model correctly simulates the evolution from a single spore to a pellet. Diffusion of oxygen is included in the model. The simulated tridimensional structures have a fractal nature; and the fractal dimension, determined by a box-counting method, increases during growth. The fractal dimension only depends on the mass of the pellet and is not affected by model parameters such as tip extension rate and branching frequency. Realistic pictures are obtained and the radius of the pellet increases at a constant rate. The influence of model parameters (tip extension rate, branching frequency, minimum porosity) on dissolved oxygen concentration profiles, biomass concentration profiles, rate at which the pellet diameter increases, and the evolution of the fractal dimension was determined. The dissolved oxygen profiles were found to be very different from the profiles, obtained by assuming a homogenous biomass distribution within the pellet. Finally, the formation of pellets from spore aggregates is calculated and the size of the spore aggregate is found to only influence the time needed before the appearance of a pellet and not its morphology. © 1997 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...