A computer aided tool for heavy oil thermal cracking process simulation

This work presents the model for the development of a computer aided tool f or heavy oil thermal cracking process simulation. It is proposed a dual plu g flow reactor representation for the light pyrolysis of petroleum distilla tion residues in coil-type reactors. The resulting reactor model consists o f two parallel plug flows, one vapor and the other liquid, traveling at dif ferent speeds in a coil. Reaction is assumed to be the rate controlling pro cess with equilibrium between the phases. Because of the pyrolysis reaction s and pressure drop, vaporization takes place continuously along the coil s o there is a decrease in the liquid hold-up. The model derived uses a heuri stic lumping approach based on pilot plant data and the resulting pseudokin etic scheme presents a certain feed independence within the range of stocks available for the study. An industrial case study (delayed coking) is expl ored to provide insight into the problem of reconciling the kinetics of pyr olysis and carbonization for the upgrade of distillation residues. (C) 2001 Elsevier Science: Ltd. All rights reserved.