Experimental Investigation of Ash Deposition during Co-Firing of Coal with Sorghum Pellet Using Drop Tube Furnace

Co-firing technology for biomass waste is a green energy solution for coal-fired power plants (CFPP) which is a major contributor of global carbon emission. Sorghum can become a suitable biomass as a co-combustion with coal given its versatility as a single source of starch, sugar and lignocellulose. The potential of sorghum in Flores, Indonesia is very large, it can produce approximately 48 tons/ha.year of dry sorghum biomass. Research about cofiring between coal and sorghum as a CFPP fuel is still limited. However, biomass can cause serious slagging and fouling problems in boilers. Therefore, it is important to conduct laboratory scale research to examine the effect of coal and sorghum blended which will be used as CFPP fuel. This research will focus on the aspect of slagging fouling caused by coal and sorghum blended using drop tube furnace (DTF) equipment. The co-firing composition of sorghum used in this study was 5%, 10% and 15%. Visual observations as well as ash analysis were conducted with the SS310 probe in adjusted temperature of 550 and 600C according to the wall tube temperature in the boiler to examine the ash deposit that occurred. There is a significant effect on sorghum and coal blended with a composition of 15%. There was no sticky material on probes 550C and 600C when compared to the others. However, the ash deposits that occur in coal and sorghum blended has the higher amount than in origin coal due to the high alkali content in sorghum.