Abstract
Addition of coal into the biomass gasification as an auxiliary or backup carbon resource was proposed to maintain the economical scale of treatment. The gasification performance of combined wood powder and pulverized coal was examined in the lab-scale test furnace of the down-flow entrained bed. The wood powder sieved under 200 μm and bituminous coal pulverized under #200 mesh were used as a combined fuel sample and fed pneumatically with nitrogen into each different burner set on the top of the furnace. Oxygen was supplied as the gasification agent. The maximum temperatures in the furnace were over 1500 K, but were not beyond the fusion temperature of coal ash, 1700 K. This temperature region is essentially important to allow the fly ash captured in the down-flow of the entrained bed without slag yield. The carbon conversion to gas achieved at higher efficiency than 80-90 percent although the residence time of gas-solid flow in the furnace was as short as a few seconds. The slag formation of coal ash was not observed at the temperatures in this work.
