HYDROCRACKING OF N-ALKANE MIXTURES ON PT H-Y ZEOLITE - CHAIN-LENGTH DEPENDENCE OF THE ADSORPTION AND THE KINETIC CONSTANTS/

The conversion of a mixture of n-hexane, n-heptane, n-octane and n-non ane, in the presence of hydrogen over zeolite Pt/H-Y is modeled using a multicomponent adsorption-reaction scheme. Adsorption parameters for the relevant hydrocarbon molecules are determined using the chromatog raphic technique. Intrinsic reaction parameters are obtained by the fi tting of the model to reaction rate data from catalytic experiments, u sing the independently determined adsorption parameters. Preferential conversion of the longer n-alkanes in mixtures is caused by competitiv e adsorption favoring the heavy compounds. Apparent reaction rates in mixtures are controlled by adsorption, increasing with chain length of the n-alkanes, rather than by the individual intrinsic reaction rates of the different n-alkanes, which are similar.