Co-firing characteristics of wood pellets on pulverized coal power plant

Abstract

Co-firing testing of the wood pellets was carried out in Pulverized Coal Boiler type tangential firing with a capacity of 315 MWe to determine the effects on the performance, emission, and characteristics of the operational boiler parameters such as mill outlet temperature (MOT) and furnace exit gas temperature (FEGT). Fuel was mixed on stockpile with a fuel composition of 5 % wood pellets and 95 % coal. Fuel was initially filled in four bunkers for each mill operated. The co-firing testing was carried in six hours and the data was collected for four hours after the stabilization period. To observe the further impact on the performance, emission and characteristics of operational boiler parameters, two different fuel (100 % coal fuel and 5 % wood pellet – 95 % coal fuel) were set up through the boiler. The result shows that co-firing by 5 % of wood pellets contributed to the decreasing FEGT by 15 °C from 1,192 °C to 1,177 °C equal to 1.27 % lower than the existing condition. The mill outlet temperature is relatively the same for two types of fuel with mill current slightly increasing by 0.70 Ampere. Emissions of SOx increased by range from 8.22 % to 20.51 %. NOx content in flue gas on the air heater inlet side is almost the same of 310 mg/Nm3 and only an increase of 3.62 % on the air heater outlet side. This test also affected specific fuel consumption which has increased by 4.40 % from 0.556 kg/kWh to 0.580 kg/kWh.