Research progress of biomass conversion and utilization technology

Supercritical water has the characteristics of dissolving most organic matter and gas, high density and low viscosity, and the heat utilization efficiency of biomass gasification and pyrolysis in supercritical water is higher than that of conventional ones, so the biomass supercritical water gasification technology has been widely valued and has great development potential. Because the reaction temperature and reaction pressure required for supercritical water gasification have high requirements for equipment and materials, the research on supercritical water gasification of biomass has been limited, and the research on this aspect started late in China. With the continuous understanding and research of the unique physical and chemical properties of supercritical water, it has been found that supercritical fluid can be used in the pretreatment of biomass, pyrolysis, liquefaction and preparation of biodiesel to transform and efficiently utilize biomass resources. Such as biomass supercritical pyrolysis hydrogen production, biodiesel supercritical preparation, biomass supercritical liquefaction and biomass supercritical pretreatment. The supercritical conversion technology of biomass has great application potential, especially in the fields of gasification of supercritical water to hydrogen and esterification of supercritical methanol to biodiesel. However, due to the demanding reaction conditions of supercritical fluid, high requirements on energy consumption and equipment, and large losses, resulting in high production costs, the current application of supercritical fluid in biomass energy conversion is mostly in the research stage, and there is still a huge space for development in the research and improvement of technology and systems.