Production of bio-hydrogenated diesel from palm oil using Rh/HZSM-5 in a continuous mini fixed-bed reactor

Abstract

The hydro-processing of palm oil in a continuous mini fixed-bed reactor to produce bio-hydrogenated diesel (BHD) was investigated to improve the production biofuel. Rh/HZSM-5 was used as catalyst to facilitate cracking, hydrogenation, and isomerization reactions. The operating parameters included reaction temperature (400–500 °C), pressure (7–34 bar), weight hourly space velocity (10.0–43.7 h−1), and hydrogen-to-oil molar ratio (36.6:1–220.9:1). The optimal conditions were at reaction temperature of 500 °C, pressure of 34 bar, 0.05 g of catalyst, WHSV of 43.7 h−1, and hydrogen-to-oil molar ratio of 36.6:1. The yield and productivity of C8-C18 were 51.13% and 21.2 kgproduct/kgcath, respectively. The catalyst stability was demonstrated for 600 min. Fuel properties including density, viscosity, cloud point, pour point, acid value, and oxidation stability of the product collected at the optimal conditions were measured and compared with the US and European standards as well as the commercially available B-20 and B100-FAME in Thailand. The extremely short residence time (< 1 min) and the significant decrease in the use of hydrogen were observed along with the high-quality fuel when compared to the other processing techniques.