Kinetics Study On Hydrolysis And Hydrocarbon Generation Of Fatty Acid Ester Catalyzed By Marine Carbonate Hydrocarbon Source Rocks At Low Temperature

Fatty acids are regarded as one of the important precursors for the process of hydrocarbon generation. It has been found that main forms of the fatty acids existing in nature are fatty acid esters. In this paper, methyl stearate is chosen as the model compound, to study the influencing factors and the kinetics of its hydrolysis and hydrocarbon generation reaction catalyzed by S3 and S4 hydrocarbon source rocks that had been extracted with organic solvents at simulation conditions. The kinetics of fatty acid ester hydrolysis and hydrocarbon generation is the main approach to quantitatively investigate the catalytic effects of minerals. A series of simulation experiments were carried out to investigate the effect of mineral. The contents of the study include: The effects on the hydrolysis and hydrocarbon generation of methyl stearate, such as the reaction time, pH value, salinity, reaction temperature and pressure. Various kinetics parameters including the reaction order, the overall activation energies, overall rate constants and the pre-exponential factors are obtained by means of many kinetics experimental data under the simulation conditions. The relation of pH value and electrode potential value in the water solution is studied in the presence of mineral. The results indicate that the temperature, pressure, pH value, and the salinity can influence the hydrolysis and hydrocarbon generation reaction of the methyl stearate, and the factors studied all play important roles in the process of the hydrolysis and hydrocarbon generation of fatty acid ester. The catalysis of the minerals is obvious in promoting the hydrolysis and hydrocarbon generation of methyl stearate at geological low temperature. The catalysis of minerals is reflected by influencing reaction activation energies and pre-exponential factors. The study also suggests that both the hydrolysis and the hydrocarbon generation reaction can be treated as consecutive reaction, the hydrolysis reaction is first order reaction and the hydrocarbon generation reaction is zero order reaction.