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Show COMBUSTION 2000 - BURNING COAL IN THE TWENTY-FIRST CENTURY D. J. Seery United Technologies Research Center Introduction The need for improved methods of utilizing coal is clear. To maintain economic growth without undue reliance on foreign sources of energy the U.S. must develop new techniques to use our coal resources with significantly higher efficiency and lower stress on the environment. This will be necessary under all energy projections, even with the most optimistic growth for conservation, nuclear energy and even renewable energy. To make a substantial improvement in overall thermal efficiency will require a change from the traditional Rankine cycle steam turbine to Brayton cycle gas turbines. Modern gas turbines are already generating power running on oil or natural gas with low pollutant emissions and high efficiency, especially in combined cycles. Coal combustion introduces new problems for gas turbines because of the corrosive nature of the ash content. The Department of Energy has had a program for several years on direct coal-fired gas turbines, mostly involving slagging combustors to minimize ash contact with turbine blades. Yhile this program has focused on small gas turbines, the big rewards will come with the large aeroderivative or frame-type gas turbines. For these machines complete exclusion of coal combustion products is required for long term high efficiency usage. United Technologies Research Center is leading a team to develop a 21st century coal-fired power generation system. The team is composed of UTRC plus Reaction Engineering International, PSI Technology, University of North Dakota Energy and Environmental Research Center, Bechtel, Oak Ridge National Labs and UTC's Turbo Power and Marine Division. The initial designs will be based on an indirect-fired gas turbine in a combined cycle system. It will be essential to exclude coal combustion products fro the gas turbine and thus a major effort will be the development of a high efficiency ceramic air heater. This will assure that clean air will be the turbine working fluid. The goal will be to test a combustor/air heater system by the year 2000 and achieve: - a mInImum conversion efficiency of 47% - a NO and SO less than 0.15 lbs/MMBTU - partXIc ulates x less than .0075 Ibs/MMBTU - all solid wastes must be benign -( |