Molecular-Level Kinetic Modeling of Triglyceride Hydroprocessing

A molecular-level kinetic model was developed for triglyceride hydroprocessing. Triglyceride molecules were defined on the basis of the 8-22 carbon fatty acids commonly present in renewable diesel feeds. A reaction network detailing the hydrodeoxygenation, decarboxylation, and decarbonylation parallel pathways of the triglyceride chemistry was constructed. The final network contained 476 species and 1709 reactions. The network was used to build a kinetic model based on experimental data for coconut and soybean oil hydroprocessing at various temperatures, pressures, and catalyst contact times. Parameter optimization for the kinetic parameters was performed for two different catalysts. The final kinetic model provided good agreement with experimental results. Diesel cetane number and cloud point property models were also constructed and optimized on the basis of experimental data. These property models were used to study the product diesel cetane number versus cloud point trade-off to determine the end-use properties of the product fuel.