Process Balances of Vegetable Oil Hydrogenation and Coprocessing Investigations with Middle-Distillates

The hydrogenation of vegetable oil is a promising technology for the production of highly valuable diesel components. Suitable production routes are the hydrogenation on sulfided NiMo catalysts with pure vegetable oil as feedstock or their coprocessing with middle distillates. To obtain the yields of all products for a complete process balance, experimental studies with rapeseed oil and jatropha oil were performed in a pilot scale test bench. IR spectroscopy and C-13 NMR spectroscopy as well as gas chromatography were used for analyzing the liquid product. On the basis of a simplified reaction scheme, a procedure for the recalculation of specific yields and hydrogen consumption is presented and compared with the experimental values. The coprocessing experiments include the admixture of 5-20 wt % jatropha oil to a straight run middle distillate in the temperature range of 300-350 degrees C. It could be shown that the optimum reaction temperature for production of alkanes with nearly complete oxygen removal is significantly lower than that for the desulfurization of middle distillates down to 10 ppm sulfur. Concerning the cold flow properties, an admixture up to 15 wt % jatropha oil does not increase the Cold Filtration Plugging Point (CFPP) of the base middle distillate.