Unmixed combustion of coal with sulfur recycle
AssigneeGeneral Electric Company
InventorRichard K. Lyon
Life of this patent
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Abstract
An improved method of burning low sulfur coal in order to power gas turbines using unmixed combustion that ensures virtually complete oxidation of the coal, with the sulfur content of the coal being recovered as elemental sulfur for use as recycle in the unmixed combustion process. An unmixed combustion catalyst is circulated between two fluid bed reactors and becomes reduced by low sulfur coal in the first fluid bed reactor and oxidized by air in the second fluid bed reactor. The first reactor produces carbon-containing fly ash which is then separated and contacted with gases containing SO2 from the first fluid bed reactor to produce CO2, CO, H2S, COS, CS2, and elemental sulfur. The elemental sulfur is separated and a portion thereof recycled back to the first fluid bed reactor.
Claims14
A process for burning coal containing sulfur using an unmixed combustion catalyst capable of being reduced when in an oxidized state and being oxidized when in a reduced state, comprising the steps of:
- circulating said unmixed combustion catalyst between two fluid bed reactors whereby the catalyst becomes reduced by coal in the first fluid bed reactor and oxidized by air in the second fluid bed reactor and produces carbon-containing fly ash and gases containing SO2 in said first fluid bed reactor;
- separating out the carbon-containing fly ash produced by said first fluid bed reactor;
- contacting said separated carbon-containing fly ash with said gases containing SO2 from said first fluid bed reactor to produce CO2, CO, H2S, COS, CS2, and elemental sulfur;
- separating said elemental sulfur from the other gases;
- and
- recycling a portion of said elemental sulfur to said first fluid bed reactor.
An apparatus for oxidizing coal using an unmixed combustion catalyst that is capable of being readily reduced when in an oxidized state and readily oxidized when in a reduced state, comprising
- first and second fluid bed reactors;
- means for circulating a mixture of said coal and said oxygen transfer catalyst material between said first and second fluid bed reactors;
- a filter for separating carbon-containing fly ash from said first fluid bed reactor;
- means for contacting said separated carbon-containing fly ash with said gases containing CO2, CO, H2S, COS, CS2, and elemental sulfur;
- and
- means for separating and recycling a portion of said elemental sulfur to said first fluid bed.
Dependencies are inferred from the claim text.