Experimental Study of Combustion Chamber Performance Utilizing Biochar from Empty Fruit Bunch (EFB) as Fuel with Variation in Excess Air

Abstract

Palm oil mill waste is abundantly available in Indonesia as biomass. However, the inorganic part of biomass fuels causes problems related to the ash generated, leading to slagging and fouling. The slagging and fouling as deposits form on heat transfer surfaces is one of the main problems associated with biomass combustion. Reducing the deposit formation will improve the boiler’s performance. As low-calorific biomass energy, the empty fruit bunch (EFB) can be converted into high-calorific biomass solid fuel as biochar using pyrolysis. This study investigates the potential of biochar as a solid fuel that can be used as a mixed fuel with coal (cofiring) in boilers in power plants. Biochar, produced from the pyrolysis of EFB at a temperature of 500 °C, is used as fuel in the combustion chamber of a laboratory-scale boiler. The variations in excess combustion air from 20% to 40% were implemented to analyze the slagging and fouling index as well as the efficiency of the combustion chamber. From analysis, the highest combustion chamber temperature appears at 30% excess air, and the lowest was at 20%. The biochar with 30% excess air combustion has a lower potential for slagging and fouling formation. Moreover, the highest combustion chamber efficiency is around 88.06%.