Direct Combustion of Fine Coal from Coal Waste

Fine coal is a coal waste generated by washing the coal at the mines, and contains as much as 80 wt% water. Due to the lack of cost effective approaches to remove the water from fine coal before feeding into a conventional boiler, the coal producers often choose to discard the fine coal. There are already approximately 2 billion tons of fine coal in abandoned ponds and 500~800 million tons in active ponds in the U.S. with more being produced every year. We propose to directly combust the wet fine coal, without further dewatering step, in a unique process. A bench-scale demonstration will be conducted and the process’s economic advantages will be shown in Phase I and II. TDA developed a process to prepare the coal water slurry from waste coal fines A bench-scale direct combustion test on fine coal slurry was run which successfully demonstrate the feasibility of the combustion process. A conceptual design of a full-scale burner and the preliminary techno-economic analysis were completed and showed the economic advantage of this process. The coal water slurry production will be further scaled up to support a continuous combustion experiment (24-hour) on an upgraded bench-scale system. A CFD model for the coal water slurry combustion process will be developed to design the full-scale burner. The techno- economic analysis will be prepared based on detailed process modelling results and Phase II experimental data. Commercial Applications and Other Benefits: This technology can be applied to retrofit existing power plants or build new power plants at location close to the fine coal. With this new technology, over 2.5 billion tons of currently unusable fuel can be turned into electricity and its negative effect on environment is minimized.