Rockwell International Corporation

Other

USA as Represented by Secretary of the Navy

Boeing North American, Inc.

Arthur L Kohl

Richard L Gay

Laszlo A Heredy

Robert D Rennick

Albert E Stewart

Samuel J Yosim

Thomas T Shimazaki

Jaime P Ampaya

George L Bauerle

William B Suratt

Martin W Savinsky

A process of producing a combustible gas from a solid sulfur-containing carbonaceous fuel is provided. In the process, an aqueous solution is provided. A solute of the solution is a carbonate salt of an alkali metal. Particles of the fuel and the aqueous solution are mixed () to form a mixture. The mixture is fed into a gasifier () that contains molten salts of the alkali metal. The fuel is partially combusted in the gasifier to produce the combustible gas. At least a portion of the carbonate salt in the aqueous solution may be recovered () from a molten sulfide salt. The molten sulfide salt may be taken from the molten salts in the gasifier ().

Mixing and feeding aqueous solution of alkali metal salt and particles of sulfur-containing carbonaceous fuel for gasification

Aqueous black liquor is gasified in a molten salt by spraying the black liquor into an enclosed zone above the surface of a turbulent molten salt pool. The black liquor is dried by means of hot gases rising from the surface of the pool and the resulting solid particles falling into the turbulent molten salt pool are dispersed and converted into a combustible gas and a reduced melt in which sulfide comprises at least about 95% of the total sulfur present. In a preferred embodiment the product gas is purified, burned and utilized in a gas turbine.

Black liquor gasification process

A process for recovering the energy and chemical content of an aqueous black liquor utilizing a reactor containing a drying zone located above a gasification zone. The reactor contains a bed of porous solid carbonaceous material in the gasification zone. Heat losses are restricted, preferably from both zones, by the provision of a layer of insulating material about the reactor. An oxygen-containing gas is introduced into the gasification zone in an amount less than about 60% of that required for complete combustion of the black liquor such that there is produced partial combustion and gasification reactions sufficient to maintain the temperature at an upper surface of the bed in the range of from about 870.degree. to 1200.degree. C. and to form a hot combustible gas which rises from the gasification zone. A concentrated black liquor containing alkali metal, oxysulfur compounds is introduced into the drying zone and the water contained therein evaporated by contact with the hot gases rising from the gasification zone. In the drying zone there is produced a reduced temperature product gas and dry black liquor solids which fall onto the surface of the bed in the gasification zone. The dried black liquor solids are converted into the hot combustible gas which rises from the gasification zone and alkali metal salts which melt and permeate through the bed. The product gases are withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is about 80% in the form of alkali metal sulfide is withdrawn from a lower portion of the gasification zone.

An improvement in a chemical recovery process in which a hot liquid smelt is introduced into a dissolving tank containing a pool of green liquor. The improvement comprises preventing smelt explosions in the dissolving tank by maintaining a first selected superatmospheric pressure in the tank during normal operation of the furnace; sensing the pressure in the tank; and further impinging a high velocity stream of steam upon the stream of smelt whenever the pressure in the tank decreases below a second selected superatmospheric pressure which is lower than said first pressure.

Chemical recovery process using break up steam control to prevent smelt

A concentrated aqueous black liquor containing carbonaceous material and alkali metal sulfur compounds is treated in a gasifier vessel containing a relatively shallow molten salt pool at its bottom to form a combustible gas and a sulfide-rich melt. The gasifier vessel, which is preferably pressurized, has a black liquor drying zone at its upper part, a black liquor solids gasification zone located below the drying zone, and a molten salt sulfur reduction zone which comprises the molten salt pool. A first portion of an oxygen-containing gas is introduced into the gas space in the gasification zone immediatley above the molten salt pool. The remainder of the oxygen-containing gas is introduced into the molten salt pool in an amount sufficient to cause gasification of carbonaceous material entering the pool from the gasification zone but not sufficient to create oxidizing conditions in the pool. The total amount of the oxygen-containing gas introduced both above the pool and into the pool constitutes between 25 and 55% of the amount required for complete combustion of the black liquor feed. A combustible gas is withdrawn from an upper portion of the drying zone, and a melt in which the sulfur content is predominantly in the form of alkali metal sulfide is withdrawn from the molten salt sulfur reduction zone.

Gasification of black liquor

A process for the removal of sulfur oxides from two gas streams containing the same. One gas stream is introduced into a spray dryer zone and contacted with a finely dispersed spray of an aqueous medium containing an absorbent for sulfur oxides. The aqueous medium is introduced at a controlled rate so as to provide water to the gas in an amount to produce a cooled product gas having a temperature at least 7.degree. C. above its adiabatic saturation temperature and from about 125-300% of the stoichiometric amount of absorbent required to react with the sulfur oxides to be removed from the gas stream. The effluent from the spray dryer zone comprises a gas stream of reduced sulfur oxide content and contains entrained dry particulate reaction products including unreacted absorbent. This gas stream is then introduced into a particulate removal zone from which is withdrawn a gas stream substantially free of particles and having a reduced sulfur oxide content. The dry particulate reaction products are collected and utilized as a source of absorbent for a second aqueous scrubbing medium. Concurrently, the other gas stream is introduced into an aqueous scrubbing zone and contacted with the second aqueous scrubbing medium containing unreacted absorbent for the sulfur oxides. An effluent gas stream is withdrawn from the aqueous scrubbing zone and comprises a water-saturated gas stream of reduced sulfur oxide content and substantially free of particles. The effluent gas streams from the particulate removal zone and the aqueous scrubbing zone are combined in such proportions that the combined gas stream has a temperature above its adiabatic saturation temperature.

Process for removal of sulfur oxides from hot gases

An organic waste containing halogen is destroyed by treatment in a molten salt pool comprising a mixture of a basic alkaline earth metal compound with an alkaline earth metal halide. An oxygen-containing gas is introduced into the pool containing the waste to produce a gaseous combustion product and to cause the halogen present in the waste to react with the basic alkaline earth metal compound to produce additional alkaline earth metal halide.

Destruction of halogen-containing materials

The present invention provides a process for upgrading a hydrocarbon material in the presence of a molten salt in a manner which reduces the requirements for expensive ceramic materials to withstand the corrosive nature of the salt. A molten salt containing carbon is introduced into a heat generation zone which is located in a lower portion of an upwardly extending elongated reactor. Oxygen is introduced into the heat generation zone in an amount sufficient to react with substantially all of the carbon and to heat the molten salt to a desired temperature. The heated molten salt together with the gaseous reaction products of the carbon-oxygen reaction flows upwardly through the reactor to a hydrocarbon material reaction zone which is located within the reactor and above the heat generation zone. The hydrocarbon material to be treated is introduced into the reaction zone and into the molten salt where it produces gaseous reaction products and unreacted carbon entrained in the flowing molten salt. Thereafter the molten salt is introduced into a quench zone which is located above the reaction zone and into which there is introduced a quenching medium to reduce the temperature of the molten salt to a temperature below that at which expensive materials of construction, such as ceramics, are required.

Hydrocarbon treatment process

Sulfur dioxide is converted to elemental surfur by reduction with a carbonaceous material in a reaction zone containing a molten salt. Heat is provided by reacting a portion of the carbonaceous material with oxygen. In a preferred embodiment alkali metal sulfates present in the molten salt are reduced to alkali metal sulfides.

Sulfur dioxide reduction process

A method of and apparatus for removing particulate contaminants from a gaseous stream. Broadly, the apparatus comprises a housing containing a substantially vertical granular material retention member having upstream and downstream faces, a substantially vertical microporous gas filter element, said member and element being spaced apart to provide a zone for the passage of granular material therethrough. The housing further comprises a gas inlet means, a gas outlet means and means for moving a body of granular material through said zone. In operation, a gaseous stream containing particulate contaminants passes through the gas inlet means and upstream face of the granular material retention member, passing through said member, said body of granular material, the microporous gas filter element and then out the gas outlet means. The particulates carried in the gaseous stream pass into the granular material and are retained in the body of granular material and upon the upstream face of the gas filter element. The body of granular material is moved through the zone and across the upstream face of the gas filter element to scour the upstream face and remove the collected particulates, which are carried out of the housing, such that a substantially uniform pressure drop across the apparatus is maintainable during its operation.

Filtering method and apparatus therefor

A process for removing sulfur oxides from a hot gas by sequential absorption of the sulfur oxides in two zones. In each zone the hot gas is contacted with an aqueous scrubbing medium which may be a solution or slurry containing an absorbent for the sulfur oxides. The absorbent is selected from the group consisting of alkali metal carbonates, bicarbonates and mixtures thereof. The preferred absorbent is sodium carbonate. The aqueous solution is introduced into the first zone in an amount to produce (1) a dry powder reaction product containing alkali metal sulfites, and sulfates, substantially free of unreacted absorbent and (2) a substantially water-unsaturated gaseous reaction product of reduced sulfur oxide content. The gaseous reaction product of reduced sulfur oxide content is transferred into the second zone where it is contacted with a sufficient amount of an aqueous solution of absorbent to provide (1) a gaseous reaction product substantially free of sulfur oxide and (2) an aqueous solution containing alkali metal sulfites, sulfates and unreacted absorbent, which solution is used as at least a part of the aqueous solution fed into the first zone.

Absorption of sulfur oxides from hot gases

A method of removing and preferably recovering sulfur values from an alkali metal sulfide and carbonate mixture comprising the steps of (1) introducing the mixture in an aqueous medium into a first carbonation zone and reacting the mixture with a gas containing a major amount of CO.sub.2 and a minor amount of H.sub.2 S; (2) introducing the resultant product from step 1 into a stripping zone maintained at subatmospheric pressure, and contacting this product with steam to produce a gaseous mixture, comprising H.sub.2 S and water vapor, and a liquor of reduced sulfide content; (3) introducing the liquor of reduced sulfide content into a second carbonation zone, and reacting the liquor with substantially pure gaseous CO.sub.2 in an amount sufficient to precipitate bicarbonate crystals and produce an offgas containing CO.sub.2 and H.sub.2 S for use in step 1; (4) recovering the bicarbonate crystals from step 3, and thermally decomposing the crystals to produce an alkaline metal carbonate product and a substantially pure CO.sub.2 offgas for use in step 3.

Method of treating alkali metal sulfide and carbonate mixtures

A multi-stage flash, direct contact condensation method and apparatus for purifying brine is disclosed which eliminates costly apparatus previously required while maintaining adequate volume to efficiently produce potable water by use of gravity fed sprays of condensate upon which previously flashed steam is allowed to condense.

Growing community of inventors

Woodland Hills, CA, United States of America

Arthur L Kohl