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

Abstract

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.