Performance testing with high ash Indian coals and coal washery rejects in an AFBC pilot plant

Under a cooperative agreement between the US Agency for International Development (USAID) and the Government of India (GOI), a joint research project in fluidized bed combustion (FBC) is being carried out by the Bharat Heavy Electricals Ltd. (BHEL), India, and the Oak Ridge National Laboratory (ORNL). The project is aimed at obtaining basic engineering data on the combustion of high-ash Indian coals (up to 45% ash), coal washery rejects (up to 70% ash), and high-sulfur (up to 5%) US coals. Quantitative measurements of freeboard combustion, freeboard heat transfer, and freeboard gas composition are of particular interest. A FBC test facility has been erected at BHEL, Trichy. Tests have been conducted on a sub-bituminous Indian coal (38% ash) and a washery reject (65% ash) with and without flyash reinjection. The combustion efficiency was typically 95-98% for the coal and 85-90% for the rejects. Freeboard combustion was 6-9% for the coal and 3-6% for the rejects. 11 refs., 6 figs., 2 tabs.