Combustion of a High Ash and Sulfur-Containing Lignite and Its Pollution Characteristics in a Circulating Fluidized Bed Combustor

In this study a 50 kW circulating fluidized bed combustor was constructed for the combustion of high ash containing lignites. Beypazari lignite which contains 45.3% ash and 3.72% sulfur was mixed with limestone and was burnt in this combustor. Emission characteristics were investigated at different Ca/S mole ratios. It was shown that SO2 removal efficiencies reached values of 98%. At an average bed temperature of 850°C, NOx emission levels were found to be around 300 ppm. Temperature variation along the combustor (of 1.8 m in height) was found to be about 140 and 90°C for two different feed point locations of 0.17 and 0.52 m above the distributor, respectively.