A reactive distillation process for co-hydrotreating of non-edible vegetable oils and petro-diesel blends to produce green diesel fuel

A reactive distillation (RD) process for the hydrotreating (HDT) of vegetable oils and sulphured petro-diesel to produce green diesel is developed. Process intensification (PI) of a reactive separation unit that combines both, the hydrodeoxigenation (HDO) of triglycerides and free fatty acids and the hydrodesulfurization (HDS) of petroleum-diesel reactions, is carried out. PI considers the thermodynamic analysis of model mixtures of vegetable oils with hexadecane and hydrogen to determine the appropriate operating conditions (temperature, pressure and composition blends) of the RD process. Two different hydrotreating RD column configurations are proposed. The simulation of the hydrotreating RD processes is performed with the Aspen Plus environment using the PC-SAFT option to modelling the phase equilibria. Simulation results show that the performance of the hydrotreating RD process is more energy efficient and higher yields are attained when blends of vegetable oils with high free fatty acids content and petro-diesel are premixed and further hydrotreated.