Molecular kinetic model for catalytic pyrolysis of FCC gasoline by structure-oriented lumping

A molecular kinetic model for catalytic pyrolysis process of FCC gasoline in a pulsating reaction-chromatograph equipment was developed by the structure-oriented lumping(SOL)method combined with Monte Carlo(MC)simulation.SOL was applied here to describe the structure of hydrocarbons and establish reaction network.Seven structure vectors were designed to construct the hydrocarbon molecules that existed in gasoline.Ninety-two kinds of hydrocarbons covering most in FCC gasoline were generated as fundamental molecules and 2000 molecules were drawn out as a whole to represent the composition of FCC gasoline from those 92 kinds whose numbers were determined by mole fractions.By integral calculating each molecule reaction probability using the MC method,the product distribution could be obtained.Eleven typical hydrocarbons involved basically in pyrolysis reactions were chosen as model compounds.The rules of their reactions were studied,and a reaction framework was established and reaction rate constants were calculated on the basis of such rules.The results showed that the simulation method of combining SOL and MC for constructing molecular kinetic model was advisable.The simulated product yields fitted well with the experimental results.Relative errors of most product yields were less than 10%.This model also had an ability to predict product yields when prolonging the reaction time.