A single-event microkinetic analysis of the catalytic cracking of (cyclo)alkanes on an equilibrium catalyst in the absence of coke formation

Abstract

Single-event microkinetics (SEMK) are applied to model the catalytic cracking of (cyclo)alkanes on an equilibrium catalyst in the absence of coke formation. Model kinetic parameters are estimated via regression of cracking data obtained at temperatures relevant for industrial practice, 693–753 K. The obtained parameter values allow quantifying the main reaction pathways. Hydride transfer and protonation favor the formation of more stable, tertiary carbenium ions. β -scission of (cyclo)alkylcarbenium ions is preceded by skeletal isomerization and ring contraction. Small side chain cycloalkanes crack via ring-opening followed by β -scission, while the cracking of long side chain cycloalkanes occurs via dealkylation and only to a lesser extent via ring-opening. Temperature effects, such as the increase of the alkene to alkane ratio with temperature, are adequately simulated.