Co-firing of Coconut Frond with Coal Blends in Coal-Fired Power Plant: Experimental Study

Co-firing testing with a 5% coconut frond was carried out at a power plant with a capacity of 25 MWe to determine changes in the main parameters of the power plant, production costs, and the environment. Mixing coal fuel with coconut frond biomass is carried out in the coal yard. The biomass of coconut fronds has a higher content of ash, total moisture, and volatile matter than coal. In the meantime, the sulfur content and calorie value are lower by 2,308 kcal/kg as-Received base (Ar) compared to 3,990 kcal/kg of coal (Ar). Mixed fuels have the potential corrosion induction of chlorine of the minor category and the potential for slagging and fouling low and medium categories. The average temperature of the bed furnace area tends to drop but is still within the operating limit range (less than 950 °C). The temperature in the upper furnace area and Furnace Exit Gas Temperature (FEGT) when co-firing has increased and has already exceeded the standard limit with a range of 948 °C to 976°C. Total water flow increased by 1.87 t/h. The total mass flow of flue gas increased by 3%. The absorption of heat energy in the superheater area and water spray increased by 5.30% and 4.31%, respectively. Specific Fuel Consumption (SFC) also increased by 0.97%. Economically, co-firing 5% coconut frond releases saves fuel costs of 0.16 Rp/kWh. The average SO
2
emissions increased slightly, but the average NOx emissions dropped from 330.4 mg/Nm3 to 290.5 mg/Nm
³
. It is necessary to pay attention to mixing coal fuel with biomass to ensure homogeneity. This study only evaluates the impact of short-term changes on the power plant, so additional research is required to evaluate the medium-and long-term effects.