CO2-gasification of corncob in a molten salt environment

Abstract

Molten salt gasification is a promising technology for biomass conversion due to its advantages of superior heat transfer and the ability of utilizing solar energy to reduce carbon emission. In this study, the characteristics of corncob CO₂-gasification in molten salt environments is thoroughly investigated, and the approach of introducing Fe₂O₃ as catalyst to enhance the syngas yield is proposed. The results showed that the molten salts significantly promoted the conversion of corncob into gaseous products with very low tar and char yield. Compared to O₂ and H₂O atmospheres, utilizing CO₂ as gasifying agent enhanced the yield of gaseous products during the corncob gasification, especially the yields of CO and H₂. The introduction of Fe₂O₃ as a catalyst could further increase the yield of gaseous products and the cold gas efficiency (CGE), and the yield of syngas was increased into 2258.3 ml·g⁻¹ with a high CGE of 105.8% in 900 °C. The findings evidenced that CO₂ gasification in the molten salt environment with Fe₂O₃ addition can promote the cracking of tar, increasing the syngas yield significantly. Moreover, the energy required to drive the gasification process was calculated, and the total energy consumption was calculated as 16.83 GJ·t⁻¹. The study opened up a new solution for the biomass gasification, exhibiting a great potential in distributed energy or chemical systems.