Upgrading Biodiesel Derived from Palm Fatty Acid Distillate (PFAD) using 10% Ni/HZSM-5 as Catalyst

Abstract

This research aimed to determine the influence of a high-pressure batch reactor for upgrading biodiesel derived from esterification of palm fatty acid distillate (PFAD) by partial hydrogenation using ethanol as hydrogen donor and 10% Ni/HZSM-5 as a catalyst. And then, the composition of the synthesized 10% Ni/HZSM-5 catalyst was characterized by x-ray fluorescence (XRF). The experiments were designed by using response surface methodology (RSM) and there were carried out in a 1000 mL high- pressure batch reactor for 8-12 hours over a temperature range 160-250°C under pressure 10-20 bar and the biodiesel to ethanol mass ratio around 0.56:1-1.69:1 (the biodiesel to ethanol volumetric ratio around 0.5:1-1.5:1). The ester content from liquid phase product of partial hydrogenation was analyzed by gas chromatography-flame ionization detector (GC-FID) with an internal standard solution. The gas-phase product components of partial hydrogenation were analyzed by gas chromatography-thermal conductivity detector (GC-TCD). The maximum increasing yield of ethyl-ester 52.77 wt.% was achieved at reaction time 12 hours, under temperature 250°C and pressure 10 bars at the biodiesel to ethanol mass ratio around 0.56:1 (the volumetric ratio of biodiesel to ethanol 0.5:1). The best condition was operated with HZSM-5, Amberlyst 15, and non-catalyst to studies of the effect on increasing yield of ethyl-ester using other catalysts. Also, the RSM model indicated that mass ratio of biodiesel to ethanol, temperature and pressure were significantly affected by the increasing %yield of ethyl-ester. The process was not only increasing yield of ethyl-esters but also reducing more than 50% of free fatty acid (FFA) content as well. And, the percent ester content up to 96.53% which met the requirements of the international standard (EN14214).