ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The rate of formation of toluene from ethylbenzene was studied at atmospheric pressure in the temperature range of 600-725°C in conventional flow equipment. Residence times were 0.55-1.7 s, and initial partial pressures of ethylbenzene (H2O diluent) were 0.05-0.17 atm. The rate of appearance of toluene measures [1] the rate of the reaction C6H5C2H5 → C6H5CH3· + CH3·, with log k = 15.70 - 74.49 ± 3.2/θ. From the activation energy, E0 for the decomposition is estimated to be 72.2 ± 3.2 kcal/mol. The results are compatible with those of Esteban et al. [2], for which regression analysis gives log k1 = 14.79 - 70.76/θ. A composite, log k = 15.10 - 72.0/θ, fits both sets of data and is experimentally indistinguishable from Robaugh and Steina's [3] recent estimate by the VLPP technique or other estimates in the literature [4-6]. In light of the high overall conversion of ethylbenzene studied (2-80%), the industrial-type flow equipment, and the widely differing methods of characterization and analysis, the excellent agreement with the results of [2,3,5] is worthy of note. The data are compatible with current estimates of the heat of formation of benzyl radicals [6,7].
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550150507
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