Pyrolysis and Chlorination of Small Hydrocarbons

The bases of the kinetic modeling of Chlorine containing systems are addressed in this article. A kinetic scheme, involving more than 300 elementary reactions and 46 molecular and radicalic species, has been developed based on general thermochemical kinetic theories as well as the consolidated know-how in the field of hydrocarbon pyrolysis. Several comparisons with commercial and laboratory experimental data indicate a fair agreement in a wide area of lower and higher pressures (up to 30 atm) also covering the high temperature range of methylchloride pyrolysis (1000-degrees-C). Mathematical model of EDC pyrolysis furnaces already allows to evaluate process performances and alternatives accounting for fouling rates and on-stream times. The kinetic scheme can be applied to study the methane chlorination reaction system and the dichloroethane (EDC) pyrolysis system. The kinetic scheme is coupled with a furnace model and appropriate mathematical techniques to solve the resulting system of material, energy and momentum conservation equations. A coking model has also been incorporated as fouling of coils determines the run length of the furnaces. Simulation of the pyrolysis of EDC to produce vinyl chloride shows that the results are in reasonable agreement with observed values and trends. Application of the model for the design of coils and evaluation of process alternatives is discussed