The project objective is to confirm the calculations and limited laboratory data that indicate the superiority of cerium oxide to other methods available for desulfurization of fuel gases produced from coal of both high- and low-Btu value. Desulfurization trials will be run up to 2200 °F. Regeneration of the sulfur-containing cerium compounds back to cerium oxide will be demonstrated. The oxides of the common metals (iron, zinc, etc., representing present technology), are deficient as desulfurizers because they cannot operate at temperatures over 1200°F and are unable to use fuel gases high in carbon monoxide and hydrogen. Calculations indicate that the thermal efficiency of coal gasifier operations increases by 36% when the operating temperature of the gasifier increases from 1200°F to 1600 °F due to an increase in combustible components of the gas. Cerium oxide could readily desulfurize such fuel gases at 1600 °F. The 36% increase in efficiency of gasifier operation can achieve a corresponding increase in the overall thermal efficiency of any process using coal gasification. Lime (CaO) desulfurization is only capable of reducing sulfur in fuel gases to a level 50 times greater than can be achieved with cerium. The sulfur-containing products of such desulfurization cannot be regenerated and constitute a major disposal problem. Desulfurization with cerium oxide is by noncatalytic reaction of cerium oxide with sulfur in the form of hydrogen sulfide; laboratory trials have obtained 99.96% sulfur reduction from gases that contained 1.0% hydrogen sulfide.Cerium oxide created by the regeneration with either air or oxygen of the sulfur-containing cerium compounds resulting from desulfurization is equally capable of desulfurization to such levels.Anticipated Results/Potential Commercial Applications as described by the awardee:Phase I will define the sulfur-capture efficiency of cerium oxide and will confirm the validity of the predicted regeneration process. Phase II will provide the necessary kinetic data for the design, construction, and operation of a Phase III pilot plant and the eventual construction of a commercial desulfurization unit. Fuel gases from coal, produced and desulfurized at high temperatures, can be used with increased thermal efficiency, as fuels for combined-cycle power plants and for fuel cells, and to fire the boilers of electric generating stations to meet present and future EPA requireme
