Emission and Energy Characteristics of the Combination Use of Coal and Biomass in Circulating Fluidized Bed Boilers (CFBB) in Steam Power Plant

Abstract

Currently there are still many power plants using fossil fuels, including oil, gas and coal to produce electricity. The problem recently received by many developing countries, including Indonesia, is environmental degradation due to CO, SO2 and NOx emissions. Co-burning of biomass with coal is in most countries one of the most economical technologies available today for significant pollutant reduction. This study tested the combined combustion of coal and biomass in a direct co-firing Circulating Fluidized Bed Boiler (CFBB) with two treatments, namely 5 wt% sawdust biomass and 95 wt% coal, 5 wt% woodchip biomass and 95 wt% coal. The results of the two tests were compared with the parameters when using 100 wt% coal. This study aims to (1) analyze the energy produced from burning a combination of coal and biomass, and (2) analyze the emission content, including SO2, CO, NOx. The mixture of coal and sawdust produces 82 MWh of gross electricity, higher than coal and woodchips and requires the smallest amount of fuel, namely 18.7 tons per hour. The 5 wt% woodchip emitted the lowest emissions compared to the other 2 cases, namely 71.5 mg/Nm3 SO2 and 222.4 mg/Nm3 for NOx. The lowest CO emission was issued by a 5 wt% woodchip mixture, namely 4.0 ppm.