Optimization of Bio-Hydrogenated Gasoline Production from Rice Bran Oil via Catalytic Hydrocracking over Pd/Al2O3 Catalyst

Abstract

This work aims to study biofuel production from rice bran oil (RBO) using a hydrocracking reaction over 0.5%Pd/Al 2 O 3 catalyst. The Central Composite Design (CCD) was used to find optimal bio-hydrogenated gasoline (BHG) production conditions. The effects of pressure and temperature, including the interaction of the parameters under the constant liquid hourly space velocity (LHSV), were determined by the statistical methodology of surface response (RSM). The yields of liquid biofuel products and BHG, as well as BHG selectivity, were used as response values for optimizing BHG production. The results remarkably showed that pressure and temperature significantly influenced BHG production in terms of yield and selectivity. The optimal condition for BHG production was found to be at 516 ° C and 4.8 MPa, with the BHG yield of 44.21%. However, the optimal BHG selectivity was found to be at 532 ° C and 4.4 MPa with a selectivity of 69.74%. Moreover, temperature appeared to be a more dominant parameter on biofuel product yield than the pressure. This parameter had greater effects on both linear and square terms in ANOVA analysis of the biofuel product yield. Furthermore, hydrocracking was discovered to improve the heat of combustion of BHG as compared with the initial feedstock and commercial gasoline. The total acid value of BHG was also found to increase because the reaction could break the ester bond between glycerol and carboxyl groups; thus, free fatty acids were formed, causing the high value of total acid in the sample.