A comparative assessment of biofuel products from rice husk and oil palm empty fruit bunch obtained from conventional and microwave pyrolysis

Background: Pyrolysis is an alternative heating method developed to produce bio-oil, biogas, and biochar from biomass, including oil palm empty fruit bunch (EFB) and rice husk (RH) pellets. This work focused on the comparison of the products obtained from microwave pyrolysis (MP) and conventional pyrolysis (CP). Methods: The experimental work was carried out using MP and CP at 500 degrees C and 800 degrees C. The properties of biochars produced from these reactions were characterized. The biofuels were characterized using FTIR and GC-MS, while the biogas was measured using GC-TCD. The composition of the H-2 gas or syngas was also analyzed. Significant Findings: MP improved the yield of bio-oil and biochar, but the percentage of biogas yield decreased. The yield of bio-oil produced from the MP of RH and EFB pellets reacted at 800 degrees C increased significantly from 12.2 to 20.6 wt.% and 15.5 to 20.2 wt.%, respectively. The bio-oil derived from MP has a high content of monoaromatics and phenolic compounds compared to the oil produced from CP. Meanwhile, the bio-oil derived from CP contained a significant amount of polycyclic aromatic hydrocarbons. Although the yield of biogas produced via MP was slightly lower than CP, the total syngas produced from MP was significantly high for both EFB (78 vol.%) and RH (70 vol.%). For CP, only 62 vol.% and 68 vol.% of syngas was produced using EFB and RH, respectively. The findings highlight the potential of MP technology to synthesize environmentally-friendly bio-oil and biogas with a high percentage of syngas. (c) 2022 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study compared the differences in products obtained from microwave pyrolysis (MP) and conventional pyrolysis (CP) in biomass pyrolysis. The results showed that MP increased the yield of bio-oil and biochar, but decreased the percentage of biogas yield. The bio-oil derived from MP had a higher content of monoaromatics and phenolic compounds, while the bio-oil derived from CP contained a significant amount of polycyclic aromatic hydrocarbons. Meanwhile, the syngas produced from MP had a higher percentage compared to CP.