Akademik Veri Yönetim Sistemi
27th Annual International Pittsburgh Coal Conference 2010, PCC 2010, İstanbul, Türkiye, 11 Ekim 2010, cilt.3, ss.1730-1745
In this study, combustion and co-combustion of two biomasses and a Turkish lignite coal was carried out in a circulating fluidized bed combustor. A lignite coal which has high sulfur content and two biomasses were used in the experiments. The biomasses were hazelnut shells and woodchips. The combustion system consists of a circulating fluidized bed combustor column, a fuel feeding system, electrical heaters, and two cyclones. Its thermal capacity is 30 kW. The combustor column has an inside diameter of 108 mm and a height of 6 m. The temperatures along the column are observed with thermocouples located at specific heights. The temperature of the column is kept at about 850°C during the combustion experiments. The pressure drops along the combustor column, cyclone, downcomer, and loopseal are continuously measured and observed in order to determine the solid mass flux within the combustor. A series of combustion tests for each fuel and mixture was performed in order to investigate the effect of excess air ratio on the flue gas emissions. During the combustion experiments, CO2, CO, O2, NO, and SO2, emissions in the flue gas was continuously measured by ABB-AO2000 Advanced Optima continuous gas analyzer and recorded. The results of the experiments showed that as the biomass ratio in the fuel mixture increases for co-combustion, the combustion takes place more in the freeboard of the main column. Therefore, the maximum temperatures are seen in the freeboard rather than in the bed. Also the CO emissions increase as the biomass percentage increases in the fuel. Biomass fuels have high CO emission which indicates that a secondary air addition is required for the system. Secondary air injection into the freeboard may be a good solution to decrease the CO and also hydrocarbon emissions and to increase the combustion efficiency.