The Effect of the Reactor Type on the Selectivity of Thermal Reactions of p-Xylene in Temperature Gradient Systems

• Published in: Bulletin of the Chemical Society of Japan Vol. 64; no. 3; pp. 1000 - 1004
• Main Authors: Kawakami, Shigenobu, Iwaki, Shingo, Nakada, Masahiro, Yamaguchi, Tatsuaki
• Format: Journal Article
• Language: English
• Published: Tokyo The Chemical Society of Japan 01.03.1991; Chemical Society of Japan
• Subjects: Applied sciences; Chemical industry and chemicals; Exact sciences and technology; Industrial chemicals; Organic industry; Continuous process; Batchwise; Hydrocarbon; Benzenic compound; Selectivity; Thermal reaction; Experimental study; Reactor; p-Xylene; Temperature gradient
• ISSN: 0009-2673; 1348-0634
• DOI: 10.1246/bcsj.64.1000

Thermal reactions of p-xylene were investigated in two kinds of reactors, batch type and flow type, with a large temperature gradient. Excellent differences of the resulting products were observed between these two types of reactors. As for a batch type reactor, 4,4′-dimethylbibenzyl was produced in a high yield with [2.2]paracyclophane and toluene as by-products, and as for a flow type reactor, toluene was obtained as a major product with a low selectivity of 4,4′-dimethylbibenzyl, respectively. These results were different from those of the conventional fast flow pyrolysis method in which [2.2]paracyclophane or poly(3,6-dimethylene-1,4-cyclohexadiene) was formed as a major product. These differences can be accounted for by the partial separation of a reaction mixture caused by the thermal diffusion effect, which arises when the mixture is subject to a temperature gradient.