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.