Patent ID: 8529648

Claim:
A process of producing a combustible gas from a solid sulfur-containing carbonaceous fuel, comprising: providing a first aqueous solution, a solute thereof being a carbonate salt of an alkali metal; mixing particles of said solid sulfur-containing carbonaceous fuel and said first aqueous solution to form a slurry; pumping and feeding said slurry into a gasifier, wherein said feeding being through a spray system forming a spray of said slurry, said spray comprising of a number of flowing droplets to accommodate rapid drying of said slurry; feeding pressurized oxidant gas into said the gasifier; said gasifier having an upper drying zone whereby water evaporates out of said flowing droplets of aqueous slurry forming at least partially dried droplets comprising of said fuel and said salt of alkali metals; a lower gasification zone whereby said salt is melted to form smelt and said fuel is gasified by reaction with said oxidant aided by catalytic effect of said salts at a temperature in the range of about 900° C. to 1150° C. to produce a gasifier off-gas, containing carbon monoxide and water vapor, and a hot liquid smelt containing molten alkali metal sulfide; said gasification zone incorporating a pool of liquid smelt, whereby molten salt droplets and non-gasified particles of fuel land and further gasify inside said pool; recovering said gasifier off-gas as said combustible product gas; recovering said first aqueous solution by draining said smelt into a quench tank operating at essentially the same pressure as the gasifier; quenching and dissolving said smelt in an aqueous medium to form a second aqueous solution; contacting said second aqueous solution with a carbon dioxide-containing gas, depressurizing, heating, and stripping hydrogen sulfur from said aqueous liquid, to form said first aqueous solution comprising said solute of alkali metal carbonate salt; and utilizing the depressurized and regenerated first solution as the principal fluid to make said slurry.