Experimental study on steam gasification of sawdust with high temperature copper-containing slag

Experiment of sawdust steam gasification catalyzed by copper-containing slag was carried out using its waste heat as external heat source. Catalytic activity components of the slag were inferred and catalytic activity was evaluated by analysing its phase composition before and after the catalytic reaction by XRD and characterization of gas product. Sensible heat and utilization rate of waste heat of the slag were calculated by determining the temperatures of catalyzed copper slag before and after gasification. The results show that untreated copper slag presents characteristic peaks of Fe₂O₃ and the number of characteristic peaks of Fe₂O₃ and Fe₃O₄ is reduced and their strength weakened for calcined copper slag after catalytic gasification. Volume fraction of H₂ significantly is increased and volume fractions of CH₄ and C₂H₄ are significantly reduced after catalytic gasification. It is infered that catalytic components of the slag are Fe₂O₃ and Fe₃O₄ and its catalytic activity is determined by the content of Fe₂O₃ and Fe₃O₄. The higher the content of Fe₂O₃ and Fe₃O₄, the better the catalytic activity of the slag. The recycling sensible heat of the slag and utilization rate of waste heat are 151.89~237.48 kJ/kg and 18.49%~22.63% respectively for the temperature reduction of the slag by 130~240°C within the gasification temperature range from 720 to 950°C.