Abstract: Based on the structure-oriented lumping method (SOL), 21 structural units including hydrocarbon structure and hetero atom structure were designed, and the structural vector of 2 791 kinds of typical molecules representing 55 kinds of delayed coking raw material molecules was constructed. Based on the mechanism of delayed coking reaction, The 38 reaction rules of 10 kinds of reactions, including carbon chain cleavage, dehydrogenation, ring opening, diene synthesis, H2S removal, CO2 and CO removal, as well as hydrodenitrogenation, were developed and used to describe the entire delayed coking reaction network. Based on the corresponding reaction rate constants and reaction heat data, a set of differential equations for reaction kinetics was established. The improved Runge-Kutta method was used to solve equations, building a kinetic model of delayed coking adiabatic reaction based on structure-oriented lumping to predict the typical molecular compositions and product distributions of delayed coking process. The prediction accuracy of the established kinetic model is better than that of the isothermal reactor model without considering the reaction thermal effect. Using the model of lumped adiabatic reactor guided by delayed coking structure to simulate the process of delayed coking reaction under different coking reaction temperature and cycle ratio, the prediction errors of gas, gasoline, diesel, wax oil and coke yields were less than 1.7 percentage points and the prediction errors of typical molecule content in products did not exceed 2.0 percentage points.

Key words: delayed coking, adiabatic reaction, structure oriented lumping, reaction kinetics