Catalytic Upgrading of Bio-oil Produced from Pyrolysis of Rice Husk

Rice husk is one of the most widely available agriculture residues. It was a promising eco-friendly alternative source of renewable energy in the context of current energy scenarios. Fast pyrolysis technologies can transform rice husk into bio-oil considering its physical and chemical properties. Catalytic pyrolysis experiments have been carried out on Japanese rice husk to obtain bio-oil using a fixed-bed pyrolysis reactor with the use of the catalyst and comparison was done to analyze the changes in the bio-oil properties and yield. The fast pyrolysis of rice husk has been performed in the temperature range of 400-600 °C using the experimental pyrolysis reactor. The objective of this research is to explore the possibility to upgrade bio-oil produced from rice husk. The catalytic cracking is the most promising bio-oil upgrading processes, and it can remove oxygenated compounds from bio-oil via H₂O, CO and CO₂. The result showed that by using two heating units, even without catalyst, the upgrading was achieved well. In this research, two heating units were employed so that the raw bio-oil will separate in the first heating unit and the cracking in the second heating unit. The raw rice husk bio-oil produced and the upgraded bio-oil were characterized by measuring their element content, water content and the chemical composition of its organic fraction. The catalysts used were HZSM-5 zeolite and other non-commercial catalyst like rice husk ash which were appropriately effective in the bio-oil crack upgrading to reduce cost.