MODELING OF THERMAL STEAM CRACKING OF NORMAL-HEXADECANE

The modeling of experimental thermal steam cracking of pure n-hexadecane in a laboratory-scale tubular quartz reactor at atmospheric pressure was investigated. Comparison of experimental and simulated data for a weight ratio of steam to hydrocarbon within 2.7-2.9 over the range of temperature from 600 to 750-degrees-C is given. An evolutive kinetic model is presented. For temperatures up to 650-degrees-C, where secondary reactions are still negligible, a kinetic model, based upon 141 radical reactions, 20 molecular species, and 18 radical species, is shown to allow the prediction of gaseous and liquid product concentration distributions as a function of residence time. But, for higher temperatures, it was necessary to take into account the radical reactions of liquid olefin decomposition and molecular Diels-Alder cycloaddition reactions. This complementary model for high conversion involves 357-360 reactions and 31 radical and 22-25 molecular species, depending on the temperature.