Experimental studies of biomass gasification with air

Abstract

In this work, experimental studies of biomass gasification under different operating conditions were carried out in an updraft gasifier combined with a copper slag reformer. The influence of gasification temperature, equivalence ratio (ER) and copper slag catalyst addition on gas production and tar yield were investigated. The experimental results showed that the content of H₂ and CO, gas yield and LHV increased, while the tar yield and the content of CO₂, CH₄ and C₂H_x in the gas product decreased with the temperature. At 800 °C, with the increase of ER, the LHV, the tar yield and the content of H₂, CO, CH₄ and C₂H_x in gas products decreased, while the gas yield and the content of CO₂ increased. Copper slag was introduced into the secondary reformer for tar decomposition. The Fe₃O₄ phase in the fresh copper slag was reduced to FeO (Fe²+) and metallic Fe by the gas product. Fe species (FeO and metallic Fe) acted as the active sites for tar catalytic decomposition. The catalytic temperature had a significant influence on tar conversion and the composition of the gas product. Typically, the tar conversion of about 17%–54% could be achieved when the catalytic temperature was varied from 750 to 950 °C. Also, the content of H₂ and CO increased with the catalytic temperature, while that of CO₂, CH₄ and C₂H_x in the gas product decreased. It was demonstrated that copper slag was a good catalyst for upgrading the gas product from biomass gasification.