Rheinisch-westfalisches Elektrizitatswerk Ag

Rheinisch-westfallisches Elektrizitatswerk Aktiengesellschaft

Other

Georg R Gebhard

Klaus R Hein

Wolfgang Glaser

Heinz Holter

Paul W Franke

A power-plant clarifier sludge having the following dry composition:

Method of making shaped bodies for use in the construction trades from

A process is described for making flue gas gypsum from desulfurization of power plant exhaust gas. The process comprises treating the flue gas in a wash tower with a wash water suspension containing calcium oxide, calcium hydroxide or calcium carbonate and converting the scrubbed sulfur dioxide by oxidation with input atmospheric oxygen and by crystallization to calcium sulfate dihydrate crystals. A cyclic flow is drawn from the wash tower sump and delivered by spray nozzles to the wash tower. Further the process comprises continuously drawing an additional crystal suspension from the wash tower sump which after separation of a crystal slurry is partly fed back to the wash tower sump. The lower run-off of a cyclone separator receiving the crystal suspension is dewatered, the flue gas gypsum is separated and a clear effluent is returned to the wash tower. A partial flow is separated from the upper run-off of the cyclone separator and a solid free fluid replaces it. By control of the amount of the partial flow separated from the upper run-off the grain size of the removed gypsum or calcium sulfate dihydrate crystals is precisely adjusted and the proportion of finely divided solids in the wash tower sump is adjusted so that at least 10 weight %, advantageously 20 to 70 weight %, of the solid material contained in the crystal slurry remains in the upper run-off of the cyclone separator.

Process for making calcium sulfate dihydrate or gypsum

A dry process for desulfurization of a power plant flue gas recovers, e.g. from an electrostatic precipitator, the solids which include unreacted absorbent, absorption reaction product and fly ash, and recycles at least part of this recovered solid product to contact with the flue gas for further absorption.

Process for the dry removal of sulfur dioxide from flue gas

A method of and an apparatus for the desulfurization of the flue gases from a fossil fuel power plant. A particulate absorbent is contacted with the flue gases in a dry desulfurization step, particulates being then separated from the flue gas and being utilized in part as a secondary absorbent in a subsequent scrubbing of the flue gas. The sludge from the wet scrubbing is combined with the remainder of the dried particles from the separator to form a settable composition.

Method of removing sulfur dioxide and other toxic and noxious components

An absorbent for the dry removal of sulfur dioxide and other noxious and toxic components from a combustion flue gas which consists essentially of at least one finely divided alkaline-earth compound and an additive selected from the group which consists of at least one carboxylic acid or an alkali metal, alkaline-earth metal or ammonium salt thereof.

Carboxylic acid activated dry calcium absorbent method for removing

Absorbent for the dry removal of sulfur dioxide and like components of

A building material consists essentially of an aqueous slurry of a dry residue obtained by treating a flue gas containing fly ash from a fossil fuel combustion chamber with a finely divided absorbent consisting at least primarily of calcium oxide, calcium hydroxide and calcium carbonate to permit reaction between the absorbent and sulfur dioxide in the flue gas, and dry separation of the reacted absorbent from the residual flue gas.

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Reichshof, Germany

Georg R Gebhard