Abstract: Apparatuses and methods for removing carbon dioxide and other pollutants from a gas stream are provided. The methods include obtaining hydroxide in an aqueous mixture, and mixing the hydroxide with the gas stream to produce carbonate and/or bicarbonate. Some of the apparatuses of the present invention comprise an electrolysis chamber for providing hydroxide and mixing equipment for mixing the hydroxide with a gas stream including carbon dioxide to form an admixture including carbonate and/or bicarbonate.

Abstract: A process for desulfurizing an SO2-comprising gaseous stream comprising the steps of: a. providing an aqueous feed comprising an anion selected from a group consisting of carbonate, bicarbonate, hydroxide, sulfite, and hydrogen sulfite; b. providing an SO2-comprising gaseous feed; and c. contacting the aqueous feed and the gaseous feed to generate a desulfurized gaseous product comprising less than 40% of the feed SO2 content, and an aqueous product; wherein the contacting is carried out in a cyclone unit comprising a housing defined by a cylindrical peripheral wall and provided with at least one inlet opening for receiving fluids thereinto and with at least one swirling means, and wherein the cyclone unit is characterized in that the velocity of the gaseous stream inside the cyclone unit is between 20 m/sec and 120 m/sec.

Abstract: A process for treating flue gas containing fly ash and carbon dioxide is disclosed. In the process, carbon dioxide and fly ash are contacted with an aqueous metal hydroxide solution to convert carbon dioxide into a metal carbonate, and wherein the metal carbonate and the metal hydroxide cause the fly ash to undergo a geopolymerization reaction and form a geopolymerized fly ash. The geopolymerized fly ash is recovered for disposal or for further use, such as a concrete additive.

Abstract: Disclosed herein is a method of separating carbon dioxide from a gas mixture using a biopolymer, including: introducing hemocyte or extrapallial fluid, extracted from shells, into a reactor filled with 1 L of a solution containing a calcium source, and then dissolving the hemocyte or extrapallial fluid in the solution to form a mixed solution; and mixing carbon dioxide or a gas mixture containing carbon dioxide into the mixed solution to separate carbon dioxide from the gas mixture.

Abstract: The present invention is a process for removing hydrogen sulfide gas from natural gas by contacting a flow of sour natural gas containing hydrogen sulfide gas with a scavenging agent including a group IIA metal hydroxide such as calcium hydroxide for a sufficient amount of time to form calcium sulfide and water to yield natural gas that is substantially depleted of hydrogen sulfide gas. Sour natural gas may be percolated through a column containing a scavenging agent such as calcium hydroxide suspended as a fine particulate in water or a bed of dry calcium hydroxide granules. The scavenging agent may be periodically or continuously replenished with fresh scavenging agent rich in the selected group IIA metal hydroxide.

Abstract: In one aspect, the crude gas is contacted with a cold caustic solution to reduce levels of carbon dioxide and water. The partially purified gas is chilled in direct-contact with a hydrogen refrigerant to induce homogenous condensation of water impurity. Liquid and ice particles formed by lower temperatures are removed across an aerosol phase separating medium to produce a cooled and partially purified gas mixture which is further dried and de-carbonated across a zeolitic molecular sieve adsorbent to achieve very low concentrations of moisture and carbon dioxide in the bulk gas. In one aspect, the purified gas mixture obtained is partially liquefied, phase-separated and distilled to obtain germanium hydride, digermanium hexahydride and hydrogen gas as products. A portion of the hydrogen product can be compressed, chilled and re-used as a direct-contact refrigerant in the purification process.

Abstract: A method for effectively absorbing and removing CO2 in an exhaust gas generated during an industrial process for reducing the amount of CO2 that is exhausted into the atmosphere. The exhaust gas containing CO2 is blown into an agglomerate of solid particles containing CaO and/or Ca(OH)2 so that the CO2 is in contact with the agglomerate for fixing the CO2 in the exhaust gas as CaCO3, thereby reducing the CO2 concentration in the exhaust gas. Preferably, the solid particles contain water, and more preferably, the solid particles contain surface adhesive water.

Abstract: The instant invention presents improved means for sequestering COX and/or NOX in the aqueous phase of a gas scrubber. The instant invention presents means for the scrubbing of COX and/or NOX gas by chemically assimilating at least one of COX and NOX. The instant invention presents means for concentrating the COX and/or the NOX in the aqueous phase by creating a metal salt comprising the COX and/or the NOX. To control salt deposition, the instant invention presents means of chemical dispersion so that salt deposition can be controlled and the aqueous phase can become an efficient and effective carrier of the COX and/or the NOX. Means of controlling sulfide and sulfate emissions are presented incorporating sulfur consuming bacteria.

Abstract: An exhaust gas treatment system is provided that can sufficiently remove pollutants such as SO3 contained in combustion exhaust gas at low cost. In the exhaust gas treatment system for removing pollutants such as SO3 contained in combustion exhaust gas, there is provided dissolved salt aqueous solution sprays 35A, 35B, and 35C, that spray an Na2SO4 aqueous solution obtained from desulfurization effluent of a wet desulfurization system, into a flue though which the combustion exhaust gas flows.

Abstract: A method for reducing acid gases in a flue gas, the method comprising reacting biosolids comprising a scrubbing agent with a flue gas comprising an acid gas, thereby reducing the amount of acid gas in the flue gas is disclosed. Also disclosed is a flue gas scrubbing process comprising: combusting a fossil fuel and biosolids comprising a scrubbing agent, thereby producing a flue gas comprising an acid gas, wherein the flue gas has a reduced amount of acid gas compared with flue gas produced from the combustion of the fossil filet alone. A flue gas scrubbing process comprising providing a stream of biosolids that includes a hydroxide or an oxide of a Group IA or IIA element, providing a flue gas comprising an acid gas, and reacting the biosolids stream with the flue gas so as to reduce the amount of acid gas in the flue gas is also disclosed.

Abstract: A method and system for removing hydrogen sulfide from gaseous process streams, such as sour gas streams are disclosed and described. A gaseous stream containing hydrogen sulfide can be contacted with an aqueous silicon-containing composition under high shear conditions to form a sweetened gaseous product. The gaseous product has significantly reduced hydrogen sulfide content and recovered liquid and solid filtrates are generally non-toxic.

Abstract: The present invention includes a process for the removal of hydrogen sulfide from hydrogen sulfide gas containing gaseous streams. In one embodiment, the process comprises feeding a sulfide ion containing solution to an oxidation unit. The method further comprises feeding an oxidizing gas to the oxidation unit and contacting the sulfide ion containing solution with the oxidizing gas under sufficient conditions to form a polysulfide solution comprising polysulfide and hydroxide ions. In addition, the process comprises mixing the polysulfide containing solution with a hydrogen sulfide gas under conditions sufficient for absorption of hydrogen sulfide and precipitation of sulfur from the polysulfide containing solution. In some embodiments, the process comprises separating the precipitated sulfur from liquid.

Abstract: A method and system for removing hydrogen sulfide from gaseous process streams, such as sour gas streams are disclosed and described. A gaseous stream containing hydrogen sulfide can be contacted with an aqueous silicon-containing composition under high shear conditions to form a sweetened gaseous product. The gaseous product has significantly reduced hydrogen sulfide content and recovered liquid and solid filtrates are generally non-toxic.

Abstract: Methods for reducing and eliminating carbon dioxide from the emissions of solid fuel fired power plants, particularly coal fired power plants, and to sequester the carbon dioxide, typically by using existing equipment. In some embodiments, the methods involve pyrolyzing the solid fuel to remove volatile matter and using the volatile matter to produce hydrogen. Additionally, the methods may involve burning the solid fuel or pyrolized solid fuel at very fuel rich stoichiometric conditions. Sequestration may include the production of a carbon dioxide-containing solution and the pumping of the solution into the ground, particularly in areas high in limestone.

Abstract: A gas combustion treatment method for the combustion treatment of an ammonia-containing gas and a hydrogen sulfide-containing gas, the method comprising a first combustion treatment step in which the ammonia-containing gas, together with a fuel, is introduced and burned; a nitrogen oxide reduction step downstream of the first combustion treatment step, in which a portion of the hydrogen sulfide-containing gas or the ammonia-containing gas is introduced and the nitrogen oxides produced in the first combustion treatment step are reduced in a reducing atmosphere; and a second combustion treatment step downstream of the nitrogen oxide reduction step, in which the remaining hydrogen sulfide-containing gas, together with air, is introduced and burned. The present invention provides a combustion apparatus suitable for use as a combustion furnace for off-gases resulting from the wet purification of coal gasification gas.

Abstract: An alternative process whereby the calcium sulphide formed in an IGCC system from calcium oxide and/or calcium carbonate can be safely and more or less quantitatively converted by reaction with carbon dioxide to calcium carbonate and/or calcium oxide together with sulphur dioxide. The calcium oxide and/or calcium carbonate can be reused in the IGCC system, and the sulphur dioxide can be converted to a useful product, such as sulphuric acid. One result of this process is that since the furnace ashes do not contain a significant level of calcium sulphide, they can be safely disposed of in a land fill site.

Abstract: Methods to control hydrogen sulfide and/or arsine emissions are described. The method involves adding at least one copper compound (such as a copper(II) compound) to the material, such as material containing sulfur in a sufficient amount to control said emissions. The material that is treated with the copper compound(s) is preferably an ore, such as a valve metal containing ore.

Abstract: A process of using sodium carbonate and sodium bicarbonate solutions to remove SO3 and other acidic gases or vapors from a flue gas without substantially decreasing the amount of sulfur dioxide also present in the flue gas. Very limited quantities of such solutions are injected into the flue gas in a manner that achieves a controlled droplet size, such that the solution dries on contact with the flue gas and the resulting dry particles of sodium carbonate/bicarbonate are sufficiently small as to have adequate surface area for reacting with SO3, as well as any H2 SO4 and, to some extent, HCl vapors in the flue gas.

Abstract: BF3 CO2 or both are removed from a mixture containing these gases with B2H6 by contacting the mixture with an inorganic hydroxide such as LiOH. B2H6 is synthesized by contacting BF3 with KBH4.

Abstract: A process for recovery of fluorocompound gas from an effluent gas stream containing the fluorocompound gas and other gas components, in which at least one of the other gas components is removed, e.g., by oxidation or contacting of the effluent stream with a dry material such as an adsorbent or scrubber medium, to yield a first effluent gas mixture containing the fluorocompound gas. The fluorocompound gas is removed from the first effluent gas mixture and recovered as a concentrated fluorocompound gas, by a process such as cryogenic processing, membrane separation, and/or adsorption.

Abstract: A process for removing parts-per-million quantities of unwanted species such as oxygen, carbon monoxide, hydrogen, carbon dioxide and water from a cryogenically produced nitrogen gas stream using an oxygen removal step prior to a nickel-based catalytic adsorption step in order to eliminate the need for hydrogen regeneration in either step. Ultrapure nitrogen heated to less than 500.degree. C. is used to purge and hold the beds used for unwanted species removal, eliminating the need for hydrogen regeneration thus reducing the regeneration cycle time and cost.

Abstract: Absorbents, suitable for absorbing sulphur compounds such as hydrogen sulphide from gases and liquids, in the form of shaped units having an average size within the range 1-10 mm and containing at least 75% by weight of an absorbent material comprising copper carbonate, basic copper carbonate, and/or copper hydroxide. The units preferably have a bulk density of at least 0.9 kg/l, especially at least 1.2 kg/l. The units are preferably agglomerates containing a small amount of a binder such as a cement and may also contain a proportion of alumina to catalyse hydrolysis of carbon-containing sulphur compounds such as carbonyl sulphide or carbon disulphide.

Abstract: A process for removing H2S and mercaptans from gas streams. The process comprises contacting such gas streams with an aqueous solution of copper complex of a water soluble amine to form water insoluble copper sulfide and regenerate free water soluble amine. The copper sulfide is removed from the system and recovered. Lastly, additional copper complex of the water soluble amine is formed by reacting the regenerated water soluble amine with a copper compound.

Abstract: A method is provided for the regeneration of a scavenging compound that has been reacted with hydrogen sulfide. Regeneration is accomplished through the use of calcium oxides and sodium hydroxide. Sodium sulfide is recovered from the regeneration process in a commercially useful form. Calcium oxides are also regenerated in the process, allowing for minimal or no chemical waste.

Abstract: A process for removing Total Reduced Sulfur compounds from a gaseous stream such as those containing natural gas, industrial gas, and digester gas by oxidation with a fine flocculent acidic catalyst slurry which is regenerable during the process by pH adjustment in the absence of added heat. The catalyst slurry comprises MnO.sub.2, Mn.sub.2 O.sub.3, and Mn.sub.3 O.sub.4 having pH in the range from about 0.5 to about 6.5 and is prepared by oxidizing a divalent manganous salt in an aqueous solution having a pH in the range from about 8.0 to about 13.5 with an oxygen-containing gaseous stream.

Abstract: The present invention relates to a process for the separation of sulphur and sodium compounds from a hot process gas generated during gasification of spent liquor from the kraft pulping industry, through contact with hydrogen sulphide ion and hydroxide ion containing alkaline liquids in two or more stages, whereby the process gas in a first stage passes through a venturi throat and/or liquid trap where it is brought into contact with an alkaline washing liquid, whereby melt droplets in the process gas are separated from the gas flow and drawn off as an aqueous solution, whereby the process gas in a subsequent washing stage is brought into contact with a finely dispersed washing liquid containing hydroxide ions and hydrogen sulphide ions with a molar ratio greater than 4:1.

Abstract: A process for removing hydrogen sulfide from natural gas and other gas streams. By passing a natural gas or other gas stream having a hydrogen sulfide (H.sub.2 S) component through an aqueous solution of copper (II) ions (Cu.sup.++), the hydrogen sulfide component is converted to copper sulfide (CuS). The copper (II) ion solution is prepared by admixing powdered copper (Cu) with an aqueous solution of nitric acid (HNO.sub.3). The copper (II) ion solution is regenerated from the copper sulfide by treatment with nitric acid which liberates nitrogen dioxide (NO.sub.2). The nitrogen dioxide is used to generate nitric acid for the copper sulfide regeneration stage. In another aspect, a reaction vessel is provided which includes a centrally disposed circulation tube that enhances the mass transfer and circulation characteristics of gas purification processes.

Abstract: Method of treatment of a hot exhaust gas stream containing acid forming pollutants to produce a scrubbed exhaust and useful or benign by-products. The gas stream is first passed through a heat exchanger and then reacted with an aqueous, alkaline scrubbing solution. After the reaction the solution, now containing dissolved salts with a precipitate of any insolubles, is passed through the heat exchanger wherein it is heated by the gas stream to remove water therefrom, thereby crystallizing the dissolved salts, and wherein it serves to cool and dehumidify the gas stream in a manner to remove heat and collect water therefrom prior to its reacting with the scrubbing solution. Any remaining insolubles are non-toxic or useful, e.g. as cement kiln feed.

Abstract: A method and apparatus for manufacturing silver halide grains wherein a water-soluble silver salt solution and a water-soluble halide solution are separately introduced within a hollow cylindrical structure open at each end which is rotatable mounted about its longitudinal axis within a reaction vessel containing a colloidal aqueous solution. The colloidal aqueous solution within the cylindrical structure is stirred and mixed during the addition of the silver salt solution and halide solution and the silver halide grains which form within the cylindrical structure are immediately discharged into the colloidal aqueous solution between the outer circumference of the cylindrical structure and the reaction vessel through slits in the circumference of the cylindrical structure.

Abstract: An integrated system for the derivation of useful energy from impure steam and/or use in connection therewith, said steam containing both hydrogen sulfide and an alkaline acting component, such as ammonia, while producing liquid-phase and gaseous-phase effluents from condensation of the impure steam and substantially reducing the emission of sulfur-containing compounds to the environment. Treatment of such effluents to selectively react or bind alkaline acting components in the liquid-phase results in an augmented concentration of hydrogen sulfide in the gaseous-phase and its depletion in the liquid-phase. The gaseous-phase comprising noncondensable gas contaminants and uncondensed water vapor is separated from the liquid-phase steam condensate and treated to remove hydrogen sulfide to produce an environmentally acceptable vent gas which may be discharged to the atmosphere.

Abstract: The invention described herein discloses the use of silica gel as a catalyst for the efficient oxidation of hydrogen sulfide to elemental sulfur by nitric oxide. Concomitantly, this catalyst also promotes the hydrolysis of carbonyl sulfide to carbon dioxide and hydrogen sulfide, which then can be oxidized further by nitric oxide in the same reactor to produce elemental a sulfur. This process is designed for application in coal combustion and coal-gasification processes as a replacement for the presently available and practiced expensive methods and means for gas purification and catalytic liquid-phase conversion of these gases to sulfur.

Abstract: A preheater assembly for softening a selected portion of plastic stock material prior to severing and edge sealing is disclosed. The preheater assembly includes a pair of opposed preheaters, each having a heater tip connected to a source of heated air. The air flows through the tip to maintain it at a preselected temperature. The preheaters are mounted on opposite sides of the stock material for motion toward the material to engage it on opposite sides to heat and soften it, and away from the material to release it. Clamp elements engage the stock material during the heating and softening process.

Abstract: A wet scrubber process for removing Total Reduced Sulfur compounds and non-magnetic entrained particulates from an industrial gas is described which employs an aqueous absorbent slurry containing manganese dioxide absorbent particles. Scrubbing of the industrial gas with the absorbent slurry is followed by regeneration and recirculation of the aqueous absorbent slurry and magnetic separation to recover the non-magnetic entrained particulates separate from the manganese dioxide absorbent particles which are recycled.

Abstract: Processes for the removal of hydrogen sulphide from gas streams and for the regeneration of spent scrubbing liquor used in an absorber to remove hydrogen sulphide from a gas stream, are disclosed. In the former process, hydrogen sulphide is removed by five-valent oxovanadium which is simultaneously reduced to its four-valent state, the precipitation of which is prevented by having a sufficiently high concentration of total alkalinity present in the scrubbing solution. In the latter process the four-valent oxovanadium is oxidized to its five-valent state, preferably by an oxygen-containing gas, and a suffficently high concentration of total alkalinity is provided in the scrubbing liquor to yield a desired re-oxidation rate of the four-valent oxovanadium.

Abstract: Hydrogen sulphide is removed from gas streams in rapid and efficient manner by oxidation to sulphur. The process is effected by intimately contacting the hydrogen sulphide in the gas stream with oxygen in an aqueous medium containing a hydrogen sulphide-oxidizing catalyst to effect oxidation of the hydrogen sulphide to sulphur, and transporting the sulphur particles to the surface of the aqueous medium. The sulphur particles collect on the surface of the aqueous medium and may be removed therefrom continuously or intermittently.

Abstract: Disclosed are primary sterically hindered aminoacids for use as promoters for alkali metal salts in acid gas scrubbing. The primary sterically hindered aminoacid is selected from 1-amino-cyclopentane carboxylic acid and those represented by the formula: ##STR1## where R.sub.1 and R.sub.2 are independently selected from CH.sub.3, C.sub.2 H.sub.5, and C.sub.3 H.sub.7 ; R.sub.3 and R.sub.4 are independently selected from hydrogen and CH.sub.3 ; and n is 0, 2, or 3.

Abstract: Adding sodium sulfite in the slurry of the iron oxide slurry process for scavenging hydrogen sulfide described in U.S. Pat. No. 4,246,244, eliminates excessive foaming on start-up, stabilizes the suspension of the oxide particles in the slurry, lessens clogging of reacted particles, which otherwise interferes with cleaning out the reactor vessel, and so materially buffers the slurry as to minimize corrosion of the reactor vessel and piping. Further, adding small amounts of oxygen to the gas stream, which would be expected to cause corrosion, does not do so; instead it prolongs the usefulness of the reactant oxide particles and affords increased acid-stability to the reaction products.

Abstract: Organic sulphides are extremely malodorous compounds that are found in gaseous or aqueous effluents from many industries such as paper and pulp manufacture, hydrocarbon refinering, tanneries, and in the synthesis of organic sulphur compounds. Their removal is necessary before such effluents can be discharged into the environment.In the present invention their removal is effected using hydrogen peroxide at a pH controlled to pH 8.5 to 11.5 and in the presence of a catalytic amount of a soluble tungstate. Such a process is especially applicable to the removal of dialkyl disulphides, which are regarded as being especially difficult to remove oxidatively. In especially preferred conditions, the pH is about pH 11 and about 3-4 moles H.sub.2 O.sub.2 is used per mole equivalent of sulphur, in the presence of at least 20 ppm sodium tungstate (as W).

Abstract: Materials are described which not only extinguish fires or suppress explosions but also remove at least part of any carbon monoxide which may remain after such prior extinguishing or explosion suppressing. Examples of suitable fire extinguishants and explosion suppressants are halocarbons such as bromotrifluoromethane. The carbon monoxide removing substance may comprise Hopcalite catalysts. Other examples of suitable substances are disclosed.

Abstract: A desulphurization apparatus and method for natural gas in which red iron oxide is reacted with the sulphur compounds found in natural gas to remove these compounds from the gas. The treating solution is then recycled to regenerate the red iron oxide solution with elemental sulphur formed as a byproduct for removal.

Abstract: This invention relates to an apparatus and method for simultaneously scrubbing acidic exhaust gases and removing metal salts from alkaline waste dust from a cement plant or the like thereby producing useful products from what would otherwise be wasted. In essence the two wastes are combined in water and the resulting solution and precipitate separated in a tank. The solution is useful both to cool incoming waste gas and as a fertilizer, whilst the precipitate is suitable as kiln feed stock.

Abstract: Geothermal wells are drilled and the raw steam containing H.sub.2 S gas and debris that is released is treated with an aqueous solution containing ferric chelate and one or more water soluble cationic polymeric catalysts to remove substantially all of the H.sub.2 S and the debris is removed in a settling zone. The polymeric catalysts accelerate the oxidation of sulfide ions to sulfur solids.

Abstract: Certain impure steams, especially those from geothermal sources, are contaminated with gaseous substances such as hydrogen sulfide, ammomia, carbon dioxide, substances comprising boron, arsenic and mercury, other gases, as well as finely divided particulate solid matter in a form resembling dust or smoke. These contaminants reduce the efficiency of the steam as a heat transfer fluid and are detrimental to equipment utilizing steam as an energy source. Furthermore, discharges from the utilization of such impure steams result in pollution of the environment or necessitate expensive requirements for limiting the same. The present invention describes apparatus wherein so contaminated steam is selectively processed at superatmospheric pressure for removing one or more of said contaminants and, after reduction of its energy content by pressure reduction and/or condensation of the steam, gases substantially free of hydrogen sulfide are discharged to the atmosphere.

Abstract: A composition is provided which comprises an aqueous alkaline solution of a metal salt and black liquor, the metal salt being selected from the group consisting of iron, chromium, cobalt and nickel salts. This composition is useful in a process described for absorption of hydrogen sulfide from flue gas, followed by subsequent oxidation of dissolved sulfide to thiosulfate, if desired. The presence of the metal ions and black liquor synergistically catalyzes the overall reaction of absorption of hydrogen sulfide, followed by oxidation of the sulfide. Preferably, prior to scrubbing to remove hydrogen sulfide with the solution, the flue gas is first cooled to near its dew point, and then scrubbed with water to remove particulates. Additionally, the effluent flue gas from the absorption step is usefully scrubbed with water to recover heat, following which it is used to scrub condensates from a kraft pulp mill. The metal salt in the solution is preferably an iron salt at a concentration of about 0.002 M.

Abstract: Certain impure steams, especially those from geothermal sources, are polluted with hydrogen sulfide, ammonia, carbon dioxide, other gases, and finely divided particulate solid matter in a form resembling dust or smoke. These contaminants reduce the efficiency of the steam as a heat transfer fluid, are detrimental to equipment utilizing steam as an energy source, and result in environmental pollution or expensive requirements for limiting the same. Herein so polluted steam is selectively processed in the gaseous state to remove hydrogen sulfide therefrom, with or without removing other pollutants, to recover valuable materials therefrom, and to improve the utility of the steam as an energy source. This is done by contacting a flow of the steam with aqueous fluid reactant media comprising one or more reactive compounds of certain metals electropositive with respect to hydrogen. The valuable materials subsequently may be recovered from said media as useful byproducts. The reactant compounds may be recycled.

Abstract: An integrated system for the derivation of useful energy from impure steam and/or for use in connection therewith, said steam containing both hydrogen sulfide and an alkaline acting component, such as ammonia, while producing liquid-phase and gaseous-phase effluents from condensation of the impure steam and substantially reducing the emission of sulfur-containing compounds to the environment. Treatment of such effluents to selectively react or bind alkaline acting components in the liquid-phase results in an augmented concentration of hydrogen sulfide in the gaseous-phase and its depletion in the liquid-phase. The gaseous-phase comprising noncondensable gas contaminants and uncondensed water vapor is separated from the liquid-phase steam condensate and treated to remove hydrogen sulfide to produce an environmentally acceptable vent gas which the in part is employed in said treatment of the liquid-phase effluent.

Abstract: A process for removing hydrogen sulfide from sour gas streams is provided wherein the sour gas is passed in cocurrent flow relationship with a liquid alkaline absorption solution containing a vanadium-boron complex characterized by the properties of reacting with the H.sub.2 S thereby oxidizing [HS.sup.- ] to elemental sulfur in conjunction with reduction of the vanadium while the boron constituent is functional to inhibit formation of insoluble vanadium sulfide compounds. Regeneration of the absorption medium by contact with an oxygen containing gas is enhanced by the provision of an iron-polyamine organic acid oxidation catalyst in the absorption liquid. The process is a direct replacement for and may be operated far more economically than conventional Stretford processes.

Abstract: A method for the treatment of an effluent gaseous stream from a Kraft Recovery Boiler or the like. The effluent stream passes through a venturi section where nucleation of the particulates is initiated and larger particles collected. Subsequently, the stream flows from the venturi section with the nucleated particulates and is scrubbed to remove the particulates, TRS and sulfur dioxide. A portion of the bottoms from the packed section is recycled back to the venturi section as 15-25% dissolved solids by weight. The total solids of the liquid stream in the venturi section is maintained at 1-5% above saturation. Further concentration of a slipstream is achieved by cyclonic separation or filtration. The pH in the venturi section is controlled to agglomerate the suspended solids. The bottoms from the venturi section are subsequently concentrated externally to the venturi section to between 40-60% solids.

Abstract: Iron oxide particles having a high surface area, a high kinetic K value and composed substantially of amorphous Fe.sub.2 O.sub.3 and crystalline Fe.sub.2 O.sub.3 are drilling mud additives suitable for scavenging hydrogen sulfide. Such particles do not adversely affect the rheological properties of the mud and when reacted with hydrogen sulfide form reaction products which are acid stable. Upon completion of drilling, the drilling mud containing these iron oxide particles and their reaction products with H.sub.2 S may be left in place between the inner casing and the formation wall or the outer casing as a packer fluid.

Abstract: This invention relates to an apparatus and method for simultaneously scrubbing acidic exhaust gases and removing metal salts from alkaline waste dust from a cement plant or the like thereby producing useful products from what would otherwise be wasted. In essence the two wastes are combined in water and the resulting solution and precipitate separated in a tank. The solution is useful both to cool incoming waste gas and as a fertilizer, whilst the precipitate is suitable as kiln feed stock.