Effect of biomass type on the performance of cogasification of low rank coal with biomass at relatively low temperatures

Abstract

Cogasification of low rank coal with three kinds of biomass, i.e., Japanese cedar, rice straw, and seaweed, at relatively low temperatures were performed in a fixed bed downdraft reactor. The effect of different biomass addition on the coal gasification performance was investigated by comparing the experimental char and gas yields with the calculated prediction data. Effect of the blending ratio was also investigated. It was found that the mixing of coal with biomass revealed a synergy effect. Biomass promoted the coal gasification rate, but the extent of promoting effect was depended on the characteristics of biomass themselves. Alkali and alkaline earth metal (AAEM) content played an important role in this synergy effect. Seaweed which contained high AAEM content promoted the coal gasification significantly. Structure of coal was also found to have great effect on the cogasification performance. The results indicated that cogasification of coal with biomass is feasible at relatively low temperatures.