Investigation of the reaction mechanism regarding thermal treatment of biomass using molten salts: A kinetic study of small molecule gases formation

The conversion of biomass to produce high-valued fuel is an important way to improve the utilization rate of biomass energy . For the coupled utilization of solar energy and biomass, molten salts are used as heat storage and catalytic medium to convert biomass into combustible gases. To balance the supply of energy storage with the energy consumption for biomass conversion , the reaction mechanism regarding thermal treatment of biomass using molten salts is studied in the present research. The thermal treatment reactor combined with an online mass spectrometry is employed to characterize the gases release behavior of typical biomass components and actual biomass. In addition, a kinetic model of gas released from beech wood pyrolysis in molten salts was constructed by pyrolysis unit reactions of three typical components. The experimental results showed that molten salts can enhance the yields of small molecule gases compared to conventional pyrolysis process. For the relevance of gas release kinetics between biomass and three components, the results showed a good agreement between simulated curves and experimental data. The release of CO and H 2 was mainly from the pyrolysis of lignin, CO 2 was mainly from the pyrolysis of cellulose, and CH 4 was mainly from the pyrolysis of both hemicellulose and cellulose. In addition, the gas release characteristics of beech wood were similar to those of the lignin, which played a leading role in the gas release of actual biomass pyrolysis.