Stoichiometric Rate Equations of Catalytic Cracking of Butane Including Reactions of Coke Formation

Abstract

The catalytic cracking of butane over silica-alumina was investigated at atmospheric pressure and 450-600C in a tubular flow reactor. The overall rate of reaction obeyed first-order kinetics for butane and the rate constant waskl, 1 = 1.16 x 106 exp(-29780/RT) ml/g-cat secA set of stoichiometric equations was derived on the basis of the carbonium ion mechanism. Some reactions of coke formation were also assumed from experimental results of distributions of gaseous products, as well as the anlalysis of coke formed in the catalytic crackings of butenes, propylene, and ethylene at the same conditions with. that of buitane cracking.From these stoichiometric equations, rate equations were derived. The optimum values of the rate parameters were calcdlated from the distribution of gaseous products in. butane cracking by the Marquardt method with an adjustable step size. These values wel1 explained the experimental results.