Combustion Tests with Alternative Fuels in Oil-Designed Boilers

Several combustion test programs to evaluate alternative fuels are underway at the Pittsburgh Energy Technology Center (PETC) of the U.S. Department of Energy (DOE). The primary objective is to investigate various aspects of utilizing alternative fuels in oil-designed boilers in order to conserve petroleum fuels and to increase coal utilization. The alternative fuels investigated at PETC include coal-oil mixtures, coal-water mixtures, and solvent-refined coal. Results obtained to date indicate that oil-designed boilers can be operated with coal-oil mixtures and solvent-refined coal at their full capacities without derating; the boiler efficiencies are about the same as when firing No. 6 fuel oil, and the carbon-conversion efficiencies are generally over 99 percent. An on-going investigation indicates that oil-designed boilers can also be operated with coal-water mixtures without any supplemental fuel. In this paper, results of combustion tests with coal-oil mixtures and solvent-refined coal are summarized, and preliminary results of the coal-water mixture studies are discussed.