Liquefaction of pyrolysis derived biochar: a new step towards biofuel from renewable resources

Abstract

There are several ways to produce the renewable resource biochar, such as pyrolysis or hydrothermal carbonization. Technologies for the conversion of biochar to biofuels could contribute to suffice the growing demand for fuel. Liquid-phase pyrolysis produces about 40 wt% of biochar. Direct liquefaction of biochar is a conceivable way of producing biofuels but has not been considered yet. Direct liquefaction of biochar is carried out in a 450 ml batch reactor at the temperature of 425 °C using tetralin as a hydrogen donor solvent. Several experiments were conducted to investigate the influence of an initial heating and an isothermal stage on the conversion of biochar to biofuel. The isothermal stage was investigated at two pressure levels. Reaction time was limited to 30 min. Biochar conversion of 84% and an oil yield of 72% were observed.