Pyrolysis Heating Performance of Oil Palm Shell Waste Biomass with Carbon Surfaces

Bio-fuels from solid waste biomass have been projected to provide renewable energy for the future. The thermal conversion of waste biomass to bio-fuels requires the development of energy efficient and quick heating processes. For this reason, Microwave (MW) heating process has attracted great attention in achieving quick heating conditions. In this study, solid Oil Palm Shells (OPS) waste biomass was subjected to multimode MW pyrolysis system operated at 2.54 GHz frequency with coconut activated carbon (CAC) surfaces. The effects of increasing OPS loading were investigated at 300 W, 35 wt% CAC loading and 4 liter per minute (LPM) of N2 on pyrolysis heating performance, bio-oil yield and composition. The results indicated that increase in OPS loading provide slow heating of biomass solids. However, the final temperature reached in biomass solids were found encouraging in initiating pyrolysis conditions. 150g of OPS loading demonstrated quick and nearly uniform process heating compared to 175g and 200g OPS loading. The highest bio-oil yield of 31.76 wt% was obtained with 200g OPS loading. The phenols in the bio-oil detected remained 58.02-66.67% GC-MS area. The findings of this study reveals that the heat generated from carbon surfaces and carried with N2 gas can improve pyrolysis heating conditions in OPS solids at fairly low MW power, which can save process energy. The high phenols in bio-oil suggest potential use as chemical feedstock in petrochemical industry.