In order to guide the accurate control of the sulfides in gasoline and diesel of Fluid Catalytic Cracking (FCC) process, a molecular-level model was established based on the Structure Oriented Lumping (SOL) method. According to the molecular composition characteristics of FCC feed oil, a molecular composition matrix containing 4,148 row vectors was constructed with 24 structural increments. Using MATLAB software, the SOL reaction rules were compiled and a complex reaction network containing of about 110,000 reactions was established. According to the classification rules, the sulfides in gasoline and diesel represented by 32 and 136 structural vectors were divided into mercaptans, thioethers, monocyclic thiophenes, benzothiophenes and dibenzothiophenes, respectively. The conversion law of sulfides in gasoline and diesel was investigated by tracking their generation paths and reaction paths in the reaction network. The effects of the operation conditions on the sulfide contents in gasoline and diesel were calculated quantitatively.

A molecular-level Fluid Catalytic Cracking (FCC)-Gasoline Hydrotreating (GH) process coupling model was established based on the Structure Oriented Lumping (SOL) method to guide the precise control of the hydrocarbon compositions in gasoline. 96 FCC reaction rules and 24 GH reaction rules were formulated, and a reaction network containing about 120,000 reactions was constructed. In order to establish the FCC-GH process coupling model, the effective transfer of composition information between the two processes was realized through the molecular composition matrix of gasoline. The molecular composition matrix of gasoline was obtained according to the classification rules of the molecular composition matrix of FCC products. The conversion laws of hydrocarbon molecules in gasoline were investigated by tracking their generation paths and reaction paths. The influences of reaction conditions on the distribution of hydrocarbons in the product gasoline could be calculated quantitatively by the FCC-GH process coupling model at molecular level.

Based on the structure-oriented lumping method, a molecular-level reaction kinetic model of the delayed coking process, which adopted 24 structural increments to construct the feed molecular matrix containing 2,944 molecules, was established with a reaction network containing 74,581 reactions using MATLAB. The reliability of the model was verified by experimental results. According to the discriminant rules of structural increments, 173 structural vectors in gasoline and 1,132 structural vectors in diesel were classified into different group compositions, respectively. The model could track the reaction path of any specific molecule in the complex thermal cracking reaction network. The influences of operation conditions such as recycle ratio on the product distribution could be discovered through the calculation of the molecular-level model, which is helpful for the process optimization and precise regulation of product composition for the delayed coking plants.