A cyclic process is described for removing the oxides of sulfur from flue gas by absorption at 625 deg F and then converting the oxides to elemental sulfur by reduction of the spent absorbent. Pilot-plant experiments are reported in which a solid absorbent of alkalized alumina in free and baffled fall is used to remove SO2 and SO3 from the combustion gas of a pulverized-cool-fired furnace. The absorbent is then regenerated by heating with hydrogen or with steam-reformed natural gas. Flyash does not interfere and attrition is negligible.