Co-pyrolysis of oil palm empty fruit bunches (EFB) biochar with high-density polyethylene (HDPE) for liquid fuel production

The increasing number of vehicles has led to elevated demand for petroleum-based fuels, which are non-renewable energy sources. Consequently, the development of alternative energy sources has become crucial. In this study, the co-pyrolysis process was conducted to produce biooil as an alternative energy source. Co-pyrolysis is a thermal degradation process performed in the absence of oxygen that involves biomass and other materials. This study investigates the use of empty fruit bunches (EFB) biochar and high-density polyethylene (HDPE) with a high hydrogen-tocarbon effective ratio (H/C)eff as raw materials for co-pyrolysis. This study aims to examine the effects of torrefaction pretreatment on EFB, the impact of varying the EFB biochar to HDPE ratio (100:0, 75:25, and 55:45), and the influence of co-pyrolysis temperature (400, 450, and 500 oC) on the yield and characteristics of produced bio-oil. Experiment results indicated that torrefaction pretreatment reduced ash content, while the addition of HDPE and temperature increase improved bio-oil yield. The best operating condition with feed EFB biochar to HDPE ratio of 55:45 at a temperature of 500°C which produced the highest yield of 28.2% and optimum characteristic bio-oil with density of 0.88 g/mL, viscosity of 1.28 cP, pH of 3.7, and a calorific value of 47.34 MJ/kg.