Flue gas desulfurization process

Claim 1

The method of desulfurizing the flue gas products of combustion of carbonaceous fuel, comprising effecting the essentially complete combustion of said fuel in a combustion zone, spraying an impure solution containing mostly K 2 CO 3 and KOH into the flue gas stream at low pressure immediately downstream of the combustion zone in a zone where the temperature is sufficiently high to vaporize, volatilize or decompose the potassium compounds present to form an ionic form of potassium, thereafter reacting the SO 2 present in the flue gas stream with the potassium ions in the presence of O 2 in excess of the stochiometeric requirement to form K 2 SO 4 , thereafter cooling the flue gas stream to temperatures below the melting points of the potassium compounds present condensing the K 2 SO 4 to form K 2 SO 4 particulates and depositing K 2 SO 4 on the surfaces of other particulates present in the flue gas stream, subsequently removing essentially all of the particulates from the flue gas stream prior to the flue gas stream exiting to the atmosphere through a chimney stack, and finally water quenching all the removed particulates permitting hydraulic conveyance of the particulates to regeneration facilities.

Claim 2

The method of desulfurizing the flue gas products of combustion of carbonaceous fuel, comprising effecting the essentially complete combustion of said fuel in a combustion zone, spraying an impure solution containing mostly K 2 CO 3 and KOH into the flue gas stream at low pressure immediately downstream of the combustion zone in a zone where the temperature is sufficiently high to vaporize, volatilize or decompose the potassium compounds present to form an ionic form of potassium, thereafter reacting the SO 2 present in the flue gas stream with the potassium ions in the presence of O 2 in excess of the stochiometeric requirement to form K 2 SO 4 , thereafter cooling the flue gas stream to temperatures below the melting points of the potassium compounds present condensing the K 2 SO 4 to form K 2 SO 4 particulates and depositing K 2 SO 4 on the surfaces of other particulates present in the flue gas stream, subsequently removing essentially all of the particulates from the flue gas stream prior to the flue gas stream exiting to the atmosphere through a chimney stack, and finally water quenching all the removed particulates permitting hydraulic conveyance of the particulates to regeneration facilities.

Claim 11

The method of desulfurizing carbonaceous fuel comprising igniting the fuel in a boiler combustion zone, spraying a saturated solution of potassium carbonate and potassium hydroxide into the flue gas stream immediately downstream of the boiler combustion zone at a temperature sufficiently high to volatilize the potassium compounds of said sprayed solution to an ionic form, reacting the SO 2 persent with potassium ions in the flue gas stream in the presence of excess oxygen at a temperature in excess of 1315° C., said sprayed flue gas combining to form potassium sulfate particulates, collecting and removing said particulates dry, along with fly ash particles from the flue gas stream, separating the insoluble ash from the soluble potassium sulfate by water elution, separating the solubilzed potassium sulfate by ion exchange mechanisms, recycling the potassium, as potassium hydroxide, to the head of the system and reacting the sulfate to form ammonium sulfate.

Claim 12

The method of desulfurizing carbonaceous fuel comprising igniting the fuel in a boiler combustion zone, spraying a saturated solution of potassium carbonate and potassium hydroxide into the flue gas stream immediately downstream of the boiler combustion zone at a temperature sufficiently high to volatilize the potassium compounds of said sprayed solution to an ionic form, reacting the SO 2 persent with potassium ions in the flue gas stream in the presence of excess oxygen at a temperature in excess of 1315° C., said sprayed flue gas combining to form potassium sulfate particulates, collecting and removing said particulates dry, along with fly ash particles from the flue gas stream, separating the insoluble ash from the soluble potassium sulfate by water elution, separating the solubilzed potassium sulfate by ion exchange mechanisms, recycling the potassium, as potassium hydroxide, to the head of the system and reacting the sulfate to form ammonium sulfate.