Hydropyrolysis of lignocellulosic biomass: state of the art review

The only sustainable environmental friendly source of carbon for liquid fuel production is biomass, which is fixed by plants using atmospheric CO2. However, a major challenge for biomass-based routes is to economically produce the enormous quantities of liquid hydrocarbons needed by the transportation and chemical sector. The fast pyrolysis oil possesses many undesirable properties making it chemically far from a crude oil replacement. In hydropyrolysis process, bio-oil formed is of better quality than that formed under inert atmosphere and has relatively low oxygen content. At present, there are no systematic studies on the hydropyrolysis of biomass, which can give a detailed insight into the mechanistic aspects of the process. In addition to this, only several concepts have been proposed, which can be experimented. This review aims to provide a clear insight of the existing hydropyrolysis concepts and experiments carried out by different groups so far, along with the challenges and opportunities in the area.