Modeling the kinetics of hydrodeoxygenation of Jatropha curcas L. oil to produce green hydrocarbons by hydrotreating process
摘要
Hydrodeoxygenation is the best alternative to produce green hydrocarbons from vegetable oil. Despite the number of papers in the field, the scarcity of kinetic modeling is noteworthy. In this research, the hydrodeoxygenation of jatropha oil is reported; it was carried out using NiMoS/Al2O3 at 370 °C and 390 °C, 1–4 h of reaction time, 750 rpm, 5 g catalyst /100 g vegetable oil, and initial pressure of 8 MPa. The liquid products were analyzed by simulated distillation following the ASTM D2887 method, nuclear magnetic resonance, and Fourier transform infrared spectroscopy. The hydrodeoxygenation of the vegetable oil occurred in two consecutive reactions: The triglycerides were hydroconverted into free fatty acids, which were further hydroconverted into hydrocarbons. To model the kinetics, the power law was used, both reactions exhibiting ~ 1.6 reaction order and the average activation energy of 32.4 kJ mol−1. The hydroprocessing of vegetable oil with the sulfided catalyst at the highest temperature enhanced the hydrocarbons yields due to the oxygen removal of C–O and C= O bonds in the triglycerides occurring to a larger extent. The parity plot obtained by comparing the experimental and simulated yields exhibited a slope of ~ 1.0 and intercept of 0.002, thus validating the proposed kinetic model approach.
Graphical Abstract