Rate of formation of toluene from ethylbenzene

✍ Scribed by Hubert G. Davis

• Publisher: John Wiley and Sons
• Year: 1983
• Tongue: English
• Weight: 291 KB
• Volume: 15
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550150507

✦ Synopsis

The rate of formation of toluene from ethylbenzene was studied at atmospheric pressure in the temperature range of 600-725OC in conventional flow equipment. Residence times were 0.55-1.7 s, and initial partial pressures of ethylbenzene (HzO diluent) were 0.05-0.17 atm. The rate of appearance of toluene measures [l] the rate of the reaction C ~H ~C Z H ~ -C6H5CHj + CH;, with log k = 15.70 -74.49 f 3.2/8. From the activation energy, Eo for the decomposition is estimated to be 72.2 f 3.2 kcal/mol. The results are compatible with those of Esteban et al. [2], for which regression analysis gives log kl = 14.79 -70.76/6. A composite, log k = 15.10 -72.0/8, fits both sets of data and is experimentally indistinguishable from Robaugh and Stein's [3] recent estimate by the VLPP technique or other estimates in the literature [GI. 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).