A method for removing gaseous sulfur compounds from coal-derived fuel gases through their reaction with the iron in gasifier coal ash has been thoroughly researched, and the results have been applied for design of a commercial scale, fixed-bed, desulfurization process. Ashes with 5-23 weight percent iron oxide have been used in small reactors to sorb hydrogen sulfide from synthesized low-Btu fuel gas. Carbonly sulfide and carbon disulfide are also removed indirectly after hydrogenation to hydrogen sulfide. Results show sulfide removal efficiencies in excess of 99 percent and ash sulfide capacities up to 5.8 weight percent. A mixture of sulfur dioxide and sulfur is recovered during regeneration of spent ashes. Cyclic use of ashes improves their overall sorption reaction rate efficiency and performance. Models have been developed, verified and used to simulate operation of commercial-scale reactors. Preliminary design of a fixed bed process suitable for desulfurization of 43 MM SCF/HR of fuel gas calls for simultaneous use of six 25 x 15 ft diameter desulfurization reactors and two regeneration reactors of equal size. The estimated plant investment is 17.5 million dollars with an annual operating cost of 4.4 million dollars that is completely offset by a 20 dollar per ton credit for by-product sulfuric acid.