Kinetics of catalytic cracking of n-paraffins on HY zeolite

Kinetics and selectivity of reactions of 1‐alkenes on HY zeolite: The influence of chain length

“…Optimum values of the four parameters A, B, N and G are presented in Table 1. The validity of the parameters obtained here, and those reported previously (Abbot and Wojciechowski, 1987a;Abbot and Wojciechowski 1987b) by application of Equation (1) can be demonstrated by showing that their values are not dependent on the magnitudes of initial guesses for A, B, N and G. This is illustrated in Table 2, where we have shown that, provided the step sizes used in the fitting program are small enough, the same final values of A, B, N and G are always produced. This shows that there is a true minimum for the function, corresponding to a unique set of optimum parameters.…”

“…It has been shown (Abbot and Wojciechowski, 1987a) that reactions of n-paraffins on HY zeolite at 400°C can be described by assuming a Langmuir model to account for adsorption, and the time-on-stream theory to account for catalyst decay. Experimental results were well fitted by Equation (1).…”

“…which we have previously justified (Abbot and Wojciechowski, 1987a) in cases where alkenes are the major product species, the expression for B (Equation 3) simplifies to In the reactions under consideration, where the dominant reaction process is skeletal isomerization to produce monomethyl alkenes from their corresponding linear isomers, we can further simplify the expression for B, by assuming that the magnitudes of Kj for all methyl isomers are the same:…”

“…T reactions of paraffins on solid acid catalysts (Abbot and Wojciechowski, 1987a;Corma et al, 1985a,b;Haag et al, 1982;Pansing, 1965;Voge, 1958) but far less is known about the kinetics of reactions of olefins on these catalysts (Abbot and Wojciechowski, 1987b;Haag et al, 1982). Although olefins are not generally present in crude oil (Venuto and Habib, 1978), they are produced as primary products from cracking of paraffins and cycloparaffins (Germain, 1969).…”

“…Although olefins are not generally present in crude oil (Venuto and Habib, 1978), they are produced as primary products from cracking of paraffins and cycloparaffins (Germain, 1969). We have previously shown (Abbot and Wojciechowski, 1987a) that a kinetic model based on the assumption of Langmuir adsorption, and the time on stream theory to account for catalyst decay (Wojciechowski, 1974) can be applied to the reaction of paraffins on HY zeolite. The kinetic parameters obtained revealed that the reaction of paraffin feed was inhibited by olefinic products (Voge, 1958).…”