(653a) Investigation of Coal-Biomass Catalytic Co-Pyrolysis and Co-Gasification

The conversion of coal-biomass into energy and useful products via pyrolysis and gasification technology is a promising alternative to coal-biomass co-firing and these technologies are aimed at reducing negative environmental effects. However, one major issue with coal gasification has to deal with high temperature processing. Therefore the aim of the present study was to experimentally investigate the effect of biomass ratio and catalysts on coal gasification at low temperature using catalysts. Experiments were carried out in a bench-scale bubbling fluidizing bed reactor at 700°C, 800°C, and 900°C using subbituminous coal, hybrid poplar, corn stover and their blends. The percentages of coal-to-biomass ratio in weight percent of the raw materials studied were 100:0, 90:10, 80:20, 70:30, 60:40, 50:50, and 0:100 respectively. Additionally, the experiment was conducted in two media: N₂ and CO₂. The results showed that char and liquid yields generally decreased with increasing temperature whereas gas yield increased with increasing temperature. Further, there appeared to be positive synergistic effect of the two feedstocks on product distribution. The char yield was lower in the coal-biomass blends than were obtained when coal and biomass were treated individually resulting in a corresponding increase in product gas.