Abstract:
Kapok (Ceiba petandra) seed oil is one of many potential non-edible oil resources in Indonesia suitable as raw material for synthesizing biohydrocarbons such as green diesel. This oil consists of both saturated and unsaturated fatty acids and also contains cylcopropenoid group as malvalic and sterculic fatty acids. With proper treatment or process known as hydtrotreating (hydrogenation and simultaneous hydrodeoxygenation/decarboxylation or HDO/DCO) it can be transformed into long chain hydrocarbons equivalent to petroleum diesel with propane as the by-product. This preliminary study began with the catalyst preparation using incipient-wetness impregnation method followed by calcination and sufidation. The catalyst used in the hydrotreating process was sulfided NiMo/γ-Al2O3 with promoter (K2CO3) ratio variation in the catalyst composition. The HDO/DCO main reactions were conducted in a pressurized slurry batch reactor at 60 bar with two levels of temperatur (300 oC dan 360 oC) and reaction times of 3 dan 6 hours to evaluate the catalyst performance. Several product analysis were carried out namely FTIR, Besson and Durbetaki tests, density, Iodine number, and saponification value. The EDS analysis to catalyst samples after reaction was also conducted to measure Carbon deposition onto the catalyst surface. Experiment results using catalyst with 2.32% promoter content showed promising results in term of highest conversion and lowest cyclopropenoid content as well as Iodine number of the biohydrocarbon product, at reaction conditions of 360oC for 6 hours. The elimination of reactive cyclopropenoid content was confirmed by FTIR analysis and Besson test. Moreover, EDS anaysis showed that this catalyst also possessed the lower C deposit which may contribute to the better performace in the hydrotreating process.
