Production, upgradation and utilization of solar assisted pyrolysis fuels from biomass - A technical review

This paper documents the production, upgradation and utilization aspects of solar driven pyrolysis products namely bio-oil, biochar, and pyrolytic gas. Scattered literature information on solar thermochemical pyrolysis of different kinds of biomass reviewed holistically and consolidated for a proper insight to enhance the utilization of pyrolysis products in various applications. The major influencing parameters for better yield of pyrolysis products are identified as reaction temperature, heating rate, biomass particle size, reaction catalyst and type of biomass. All the three products (bio-oil, biochar, and pyrolytic gas) could be employed as fuel candidates in various sectors including transportation and industrial heating appliances. It is emerged from the study that the biomass-derived bio-oil must be upgraded for its use in compression ignition (CI) engines. However, the raw bio-oil could directly be used in industrial heating appliances such as furnaces and steam generators. A comprehensive insight is provided with comparative assessment of performance and emission characteristics of pyrolysed bio-oil fueled CI engines in order to address the research challenges and employ the engine's efficiency enhancement technologies in near future.