Abstract: Process of treating sulfur containing gas streams by the Claus reaction in which a recycle stream containing a reactive component is employed in a negative feedback mode to maintain the sulfur producing Claus reaction at approximately equilibrium conditions. The feedstream may contain hydrogen sulfide or sulfur dioxide in a minor amount in an inert gas background. In one embodiment the feedstream to the reaction zone contains a stoichiometrically excess amount of sulfur dioxide for the Claus reaction. Effluent from the reaction zone is passed to a hydrogenation zone where the sulfur dioxide is converted to hydrogen sulfide. Hydrogen sulfide is extracted from the hydrogenation zone effluent and recycled to the Claus reaction zone. In another embodiment the feedsteam may contain a stoichiometrically excess amount of hydrogen sulfide.

Abstract: Method and apparatus for upgrading subbituminous coal and/or lignite fuel product that does not comply with an applicable SO.sub.x :Btu standard during the combustion thereof. The fuel product is treated at the combustion site to lower the total moisture content thereof from between about 15 and 45 percent to between about 4 and 7 percent. Heavier weight ash particles are removed from the fuel product to lower the sulfur content thereof. The treated fuel product is burned while it is in the 4 to 7 percent total moisture range, thereby meeting the applicable SO.sub.x :Btu standard during the combustion process.