Bio-oil production from agricultural crop residues - a review

Abstract

India generates approximately 500 million tons of agricultural crop residues per year. This crop residue (waste) can be converted into fuel by using thermo-chemical and bio-chemical conversion routes. Thermo-chemical conversion routes mainly include gasification, pyrolysis, and liquefaction. In recent years, the pyrolysis technology for the production of bio-oil is gaining attention globally, due to its simple and efficient conversion techniques. This paper provides the updated review of bio-oil production mainly from agricultural crop residues and focuses on the different bio-oil production techniques such as fast pyrolysis and hydrothermal liquefaction; the reactor used for bio-oil production, properties, and application of bio-oil. The bio-oil produced from agricultural residues has a heating value of between 17-21 MJ/kg, exactly half of the diesel fuel. The properties of bio-oil showed the potential ability to be used as fuel in many applications such as boiler, furnaces, and diesel engines.