Abstract: In order to remove ammonia from water vapor-containing gases, in particular offgases, the gases are brought into intimate contact with warmed polyphosphoric acid, the polyphosphoric acid advantageously having a P.sub.2 O.sub.5 content of from 70 to 84% by weight and a temperature of from 120.degree. to 170.degree. C.

Abstract: After aerating sewage sludge in a composting process, a stream of process air is treated to remove odors therefrom by injecting into the airstream an atomized mixture of dilute sulfuric acid and dilute surfactant to remove ammonia and odorous organic compounds therefrom. The airstream is then oxidized with bleach to remove sulfides and treated with a hydrogen peroxide solution to remove chlorine introduced by the bleach while maintaining the oxidation reaction. A dilution fan is used to further dilute the scrubbed airstream as the airstream is exhausted to the atmosphere.

Abstract: A spray combining apparatus for use at the outlet of a fluid collection system (10) includes an outlet pipe (11) containing a diffuser and atomizer (15) adjacent an outlet opening (18). A conical rain cap (19) is mounted vertically above the outlet opening. A downwardly-facing nipple and spray nozzle (22) is positioned above the rain cap. The nozzle is supplied with a pressurized second fluid from a source (26). If first fluid is detected in the outlet, the second fluid is discharged through the spray nozzle in a selected enveloping pattern toward the outlet. As the atomized first fluid is emitted from the outlet opening, it is combined with the enveloping spray of the second fluid. The resulting neutralized or "washed" product is either suspended in the air, or is contained in the vicinity of the outlet.

Abstract: A process for the treatment of a gas stream derived from the gasification of coal is described, the process being characterized, in one embodimment, by stripping of the wash and cooling liquid used to cool and remove NH.sub.3 from the synthesis gas prior to reuse of the liquid in removal of residual solids from the product gas stream, thereby avoiding incompatibilities which may initiate or aggravate chemical precipitation, particularly that of CaCO.sub.3.

Abstract: Process for the removal of isocyanic acid from a gaseous mixture of isocyanic acid and ammonia by introducing a tertiary amine or ether at 250.degree. to 600.degree. C. The gaseous reaction mixture is passed into an inert diluent and cooled, to condense an adduct of isocyanic acid and tertiary amine or ether, and the ammonia being removed as a gas.

Abstract: A process is presented for reducing the concentration of pollutants in an effluent from the combustion of a carbonaceous fuel. The process comprises introducing a first treatment agent into the effluent at a first temperature zone to reduce the concentration of a first pollutant and introducing a second treatment agent into the effluent at a second temperature zone to reduce the concentration of either the first pollutant or a second pollutant, wherein the first and second treatment agents are introduced under conditions effective to reduce the effluent pollution index.

Abstract: Air contaminated with chemical and biological pollutants is purified by treating chemically and electrochemically in a closed system minimizing the generation of by-products for disposal. Pollutants are treated in a scrubber zone with a scrubber liquid-electrolyte comprising pollutant degrading metal ions or complexed with inert metal ions and degraded either in an electrolyzer zone or in both the scrubber and electrolyzer zones where spent scrubber liquid-electrolyte is regenerated for further cleaning.

Abstract: After aerating sewage sludge in a composting process, a stream of process air is treated to remove odors therefrom by injecting into the airstream an atomized mixture of dilute sulfuric acid and dilute surfactant to remove ammonia and odorous organic compounds therefrom. The airstream is then oxidized with bleach to remove sulfides and treated with a hydrogen peroxide solution to remove chlorine introduced by the bleach while maintaining the oxidation reaction. A dilution fan is used to further dilute the scrubbed airstream as the airstream is exhausted to the atmosphere.

Abstract: The synthesis of ammonia from hydrogen and nitrogen is carried out in a process scheme in which a liquid material is provided to react with ammonia to form an ammine to either improve the method of recovery of ammonia from a product gas stream or to upset the thermodynamic equilibrium of the H.sub.2 --N.sub.2 --NH.sub.3 system so that higher first pass conversion of the reactant gas to ammonia can be accomplished. As a result of this invention the horsepower of the synthesis gas compressor, the catalyst inventory, the operating temperature, and the operating pressure, or combinations of these factors, are reduced, having the effect of decreasing equipment and operating costs. In addition, the liquid ammine product is decomposed under conditions that allow the recovery of the ammonia as a liquid product by heat exchange with cooling water. This markedly reduces refrigeration horsepower requirements.

Abstract: The present invention relates to for deodorizing and cleaning offensive gas which comprises treatment with a lignin solution after washing the gas to remove basic offensive ingredients. The method is excellent in efficiency of deodorization and maintenance cost especially for offensive odor ingredients that are hard to decompose.

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 liquid 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: The invention relates to a method of recovering nutrients from the flue gases of a fertilizer plant by exposing hot, almost water-saturated reaction gases (4) obtained from the fertilizer production process to a countercurrent scrubbing (5, 6) and by scrubbing the hot gases (19) obtained from the drying (16) of the fertilizer, in order to recover the gaseous impurities present in the gases. According to the invention, the hot gases (19) obtained from the drying of the fertilizer are scrubbed (21) with the scrubbing solution (7) coming from the countercurrent scrubbing (5, 6) of the hot, almost water-saturated reaction gases (4), in order to concentrate this scrubbing solution (7) before it is returned to the fertilizer production process (1-3).

Abstract: An improved process for recovering usable components from waste streams containing urea, including a dilute aqueous urea solution, which result from the preparation of particulate urea products. The dilute aqueous urea solution is used to wash a urea containing waste gas stream whereby urea contained in the gas stream is dissolved in the aqueous urea solution. The aqueous urea solution thus obtained is then subjected to a hydrolysis treatment whereby the urea contained therein is hydrolyzed, and the ammonia and carbon dioxide thus formed are separated from the residual liquid stream.

Abstract: Chlorine is injected in a gaseous liquid or solution form into a hot (greater than 100.degree. C.) gas stream for the purpose of oxidizing objectionable components in the gas stream, such as, but not restricted to, SO.sub.2 and NO.sub.x, when the oxidized form of the gases is more readily removed from the gas stream. After sufficient reaction time, the gas stream mixture passes through water scubbers for the further removal of the components from the gas stream. Acidic and basic compounds of the gas stream and halogens, including excess chlorine, are also removed in the scrubbers. The pollutants remain as the corresponding oxidized acids or salts in the process effluent solution.

Abstract: A method of desulfurizing coke oven gas comprises directing the coke oven gases upwardly and in a hydrogen sulfide scrubber tower, washing the coke oven gases in a cyclic ammonia washing including admixing sulfur compounds containing waste gases and without cooling with ammonia in a degasifying unit which is supplied with ammonia containing water which is advantageously obtained from a tar separator and using the heat content of the waste gases to expel the ammonia from the water, and directing the waste gases laden with the expelled ammonia into the tower. The waste gases advantageously come from a Claus plant process and they are laden with ammonia and they are advantageously directed into the upper portion of the scrubber tower. Ammonia water is circulated in an ammonia circuit from an outlet which is advantageously located in the upper portion of the tower to an inlet which connects to the tower above the outlet.

Abstract: A process and system are disclosed for the bridging of operational standstills of an ammonia washer of a plant operating according to the semi-direct technique for the removal of ammonia from coking oven gas. During the operational standstills of the ammonia washer, the ammonia is washed out from the coking oven gas in a secondary cooler constituting three parts, an upper part (Wash Stage I) provided with stripped water from an ammonia still, a middle part (wash stage II) provided with gas water, and a lower part (wash stage III) provided with circulation water. All of the waters provided for the secondary cooler are collected in its sump, and after a separation of the circulation water necessary for the Wash Stage III, it is split into two partial streams, one serving for the recovery of stripped water for Wash Stage I and which is led into an ammonia still provided only with water vapor and the other partial stream is led into an ammonia still provided with water vapor and alkali.

Abstract: A process for regulating the NH.sub.3 content in an organic liquid that acts as a physical scrubbing agent and is used in a procedure for absorbing sour gases from gaseous mixtures. To ensure undisturbed and reliable carrying out of the scrubbing process, an ammonia-precipitating precipitant is added to the scrubbing agent and the precipitate is then separated from the scrubbing agent. Preferred precipitants include sulphuric acid and phosphuric acid. The ammonia salts are effective fertilizers.

Abstract: Gases containing CO and/or CO.sub.2 are purified by removing sulfur compounds and other impurities by catalytic reaction at elevated temperatures by a process in which the gases to be purified are passed directly through a catalyst charge containing a Cu/ZnO catalyst prepared by thermal decomposition of a mixed crystalline compound of zinc hydroxide carbonate, and the space velocity is set at 500-5,000 m.sup.3 (S.T.P.) per m.sup.3 of catalyst per hour. Preferably, the catalyst used is a Cu/ZnO catalyst which is prepared by thermal decomposition of a catalyst precursor of the general formulaCu.sub.x Zn.sub.y (OH).sub.6 (CO.sub.3).sub.2.

Abstract: An improved coke oven gas washing process for removing hydrogen sulfide is proposed wherein the coke oven gas is treated in a hydrogen sulfide scrubber by counterflow with an aqueous ammonia wash water. A stream of aqueous weak ammonia liquor is cooled and sprayed through nozzles in the mid-region of the hydrogen sulfide scrubber. A quantity of aqueous ammonia liquor, corresponding to the quantity which is sprayed through the said nozzles, is withdrawn from the hydrogen sulfide scrubber at a level below the nozzles and is introduced into the top of the said hydrogen sulfide scrubber. Ammonia vapor released at the nozzles has a higher partial pressure than the ammonia partial pressure of the coke oven gas in the region of the nozzle. The aqueous ammonia liquor from the deacidifier is the source of the cooled aqueous ammonia liquor which is introduced through the nozzles.

Abstract: The NH.sub.3 content is regulated in methanol used in a process for scrubbing out sour gases from gaseous mixtures and/or for preventing ice formation prior to the scrubbing step. The methanol is freed, after the scrubbing step, respectively of absorbed gaseous components and/or water, and reused in the cycle as scrubbing liquid and/or for preventing ice formation. A strong acid is added to the methanol from water-soluble ammonium salts. Thereby, dissolved salts are formed which are removed together with water. Deleterious trace acids are also removed by an analogous treatment with a basic compound. The acid/base treatments are conducted in succession.

Abstract: Ammonia and hydrogen sulfide are washed out of the coke oven gas and stripped from the wash liquor in the form of gases and fumes or vapors. The ammonia is decomposed in a nickel catalyzer and a small part of the decomposition gases is supplied directly to a combustion furnace, while the larger part of the combustion gases is first cooled and freed from condensate, and only then supplied to the combustion furnace. In the combustion furnace, the proportion of H.sub.2 S/SO.sub.2 needed for the Claus process is adjusted by a partial combustion of the decomposition gases. The gases from the combustion furnace are then processed in the Claus plant to sulfur.

Abstract: Hydrogen sulfide is first removed by ammoniacal liquor from coke oven gas in the bottom part of a gas scrubber. In the top part of the scrubber, two consecutively-arranged fine scrubbing stages remove hydrogen sulfide by treating the gases, in the upper stage, with a caustic soda solution or a caustic potash solution. Beneath the upper scrubbing stage is the second fine scrubbing stage fed with a subflow of an aqueous carbonate solution collecting at the outlet of the upper fine scrubbing stage and a subflow of cooled, regenerated carbonate solution discharged from the hydrogen-sulfide/hydrogen-cyanide stripper. From the hydrogen-sulfide/hydrogen-cyanide stripper, a second subflow is admixed with coal liquor for removing fixed ammonia therefrom in a separator. The separator produces water vapor with carbon dioxide vapors that are delivered to the hydrogen-sulfide/hydrogen-cyanide stripper for regenerating the aqueous carbonate washing solution.

Abstract: A process of separating in multiple stages acid components in coke oven gas such as CO.sub.2, HCN and particularly H.sub.2 S by ammonia scrubbing wherein the ammonia used in scrubbing is deacidified to remove the acid components and is recirculated to the scrubbing process at least in part as substantially pure liquid ammonia.

Abstract: The present invention provides an apparatus and process for separating and removing chemical impurities from air which impurities are difficult to absorb. The apparatus for carrying out the process of the present invention comprises a reaction tower (11, 51, 91) into which the air-gas mixture is fed, aperture means (35, 74, 96) in a wall (16, 60, 98) of the tower, at least one filter means (12, 52, 92) carried in the reaction tower, means for distributing (13, 58, 93) an absorbent medium onto the filter, collecting means (14, 54, 94) beneath the filter for collection of the absorbent medium passing through the filter, and fan means (15, 55, 95) provided in the aperture for creating a flow of air through the reaction tower for the separation of substantially all of the impurities therefrom.

Abstract: The instant invention is directed to a process for lowering the electrical resistivity of fly ash comprising adding a cationic or anionic polymer to the fly ash.

Abstract: The ammonia contained in ammonia- and hydrogen sulfide-containing gas mixtures is selectively removed through a gas washing with an aqueous ammonium sulfite-bisulfite solution, and recovered from the wash solution as a concentrated aqueous solution. For this purpose the coke oven crude gas is washed with an ammonium sulfite-bisulfite solution led in circulation, the surface tension of which amounts to below 80.times.10.sup.-5 N/cm, then the ammonia gas is driven away from the wash solution enriched with ammonia, e.g. by means of steam, and the released ammonia is recovered e.g. as aqueous ammonium solution through condensation of the vapor. The gas mixture is preferably purified or unpurified coke oven crude gas. In order to reduce the surface tension of the wash solution, alkyl sulfate, alkylamine, pyridine base, phenol or homologs thereof are added as surface active substance. The wash circulation is performed at between 15.degree. and 32.degree. C.

Abstract: A gas purification system has: a first treatment apparatus, which purifies an untreated feed gas, containing toxic ingredients such as HCN gas, H.sub.2 S gas and NH.sub.3 gas, into a primary treated gas by causing the feed gas to contact with an alkaline absorbent liquid; an absorbent-liquid-resuscitation apparatus, which refreshes the absorbent liquid, after absorbing the toxic ingredients, by bubblingly introducing a resuscitation gas; and a second treatment apparatus, which further purifies the primary treated gas into a secondary treated gas by strippingly capturing any possible remnant NH.sub.3 gas still present in the former. The resuscitation gas and the toxic-ingredient-absorbed absorbent liquid are forcibly converged by premix nozzles into combined gas/liquid jets as are injected into the absorbent-liquid-resuscitation apparatus.

Abstract: A gas purification system has: a first treatment apparatus, which purifies an untreated feed gas, containing toxic ingredients such as HCN gas, H.sub.2 S gas and NH.sub.3 gas, into a primary treated gas by causing the feed gas to contact with an alkaline absorbent liquid; an absorbent-liquid-resuscitation apparatus, which refreshes the absorbent liquid, after absorbing the toxic ingredients, by bubblingly introducing a resuscitation gas; and a second treatment apparatus, which further purifies the primary treated gas into a secondary treated gas by strippingly capturing any possible remnant NH.sub.3 gas still present in the former. The resuscitation gas and the toxic-ingredient-absorbed absorbent liquid are forcibly converged by premix nozzles into combined gas/liquid jets as are injected into the absorbent-liquid-resuscitation apparatus.

Abstract: A method and device of cooling and separating chlorides and fluorides from ammoniacal gas produced in the carbonization gasification of coal includes the addition of an aqueous salt solution having a concentration of at least one of chlorine and fluorine ions up to saturation to the ammoniacal gas in a color to form a salt solution enriched with chlorides, fluorides and ammonia compounds and a treated gas, and removing at least part of the enriched solution from the cooler.

Abstract: An improved sulfur-ammonia process for removing hydrogen sulfide from coke oven gases. In the improved process, a concentrator formerly used for standby operation is used at all normal times as an ammonia scrubber to improve the efficiency of gas separation during normal operation and is used as a concentrator for its intended standby functions during the alternative operations. In its normal function, the concentrator/scrubber functions as a scrubber to strip ammonia gas from recirculating liquid streams and to permit introduction of an ammonia-rich gas into a hydrogen sulfide scrubber to increase the separation efficiency of that unit. In the standby operation, the same concentrator/scrubber serves as a concentrator to concentrate hydrogen sulfide in a "strong liquor" stream for separate recovery as a "strong liquor.

Abstract: A method of condensing a gaseous mixture of ammonia carbon dioxide gas and water vapor to produce an ammonium carbonate solution with minimum formation of ammonium carbamate includes passing the gaseous mixture into a condenser and cooling the condensing surface to cause the gaseous mixture to condense to form ammonium carbonate solution at a temperature at which formation of solid ammonium carbamate may occur. An aqueous liquid is discharged onto the condensing surface of the condenser, the liquid having an ammonia concentration below about 260 grams per liter to maintain the concentration of ammonia and carbon dioxide on the condensing surface below a concentration at which ammonium carbamate tends to form.

Abstract: H.sub.2 S is removed from a stream of gas such as coal gas at a relatively elevated temperature (300.degree.-400.degree. F.) in a process which employs sulfates or hydroxides of nickel, iron, or zinc as sulfur absorbents. The absorbents are converted to metal sulfides during the absorption process and are regenerated by aeration. Acids produced during sulfur absorption and absorbent regeneration steps are neutralized through the addition of a base. In a preferred embodiment ammonia is also removed and elemental sulfur is produced during the process.

Abstract: A column-type apparatus for treatment of a gas stream with liquid includes a gas inlet for introducing a gas stream containing soluble compounds and solid particles into the apparatus and simultaneously imparting a cyclonic and upward flow to the gas stream. A gas-liquid mixing section above the gas inlet contains a liquid dispersing device from which liquid is vertically dispersed from the upper portion of the gas-liquid mixing section and flows downwardly and counter-currently to the gas flow wherein all the material entrained within the gas stream is completely and intimately contacted with the liquid.

Abstract: A process for deodorizing an exhaust gas containing at least one smelly material selected from the group consisting of acidic smelly materials, such as hydrogen sulfide, mecaptans, dimethyl sulfide, dimethyl disulfide and the like; basic smelly materials, such as ammonia, amines and the like; and smelly organic material, such as ketones, alcohols, aldehydes, carboxylic acids and the like is disclosed. Vapor-liquid contact of the exhaust gas with a sodium hypochlorite solution is caused in the presence of a catalyst which is a mixture of nickel peroxide and at least one carrier. In the presence of the catalyst, placed in a column, sodium hypochlorite solution falling from the upper portion of the column contacts exhaust gas rising from the lower portion of the column to promote catalyst oxidation reaction.

Abstract: A process for releasing ammonia which is bound in coal water using a pre-desulfurization plant having ammonia and hydrogen sulfide scrubbers through which crude coking plant gas is passed comprises circulating the crude coke oven gases through the hydrogen sulfide scrubber and the ammonia scrubber in succession, directing the coal water first through the ammonia scrubber while the crude coking plant gases are being also circulated therethrough after passing it first through the hydrogen sulfide scrubber. An alkali solution is also circulated through the ammonia scrubber to enrich the solution with acid components and to liberate ammonia bound in the coal water directing the coal water which has been enriched from the ammonia scrubber into the hydrogen sulfide scrubber. The process is characterized by the fact that the alkali solution which has first served for the hydrogen sulfide scrubber is added to the ammonia hydrogen sulfide scrubber.

Abstract: A process for purifying gaseous effluents containing aldehydes comprises submitting the gaseous effluents to the simultaneous action of SO.sub.2 and NH.sub.3 followed by washing with water. The ratio of the required quantities of NH.sub.3 and SO.sub.2 is between 2:1 and 3:1.When the gas to be purified naturally contains NH.sub.3, as is for instance the case in rendering plants, the quantity of NH.sub.3 to be added to the gas is reduced accordingly. Conversely when the gas to be treated naturally contains SO.sub.2, the quantity of SO.sub.2 to be added to the gas is also reduced accordingly. The most favorable ratio would correspond to a pH of the washing waters of between 7 and 7.5.

Abstract: A process for the separation and recovery of substantially pure ammonia from its admixture with gases, particularly with gases containing carbon dioxide and gases obtained from the catalytic ammoxidation of hydrocarbons to the corresponding nitriles, by scrubbing the ammonia containing gases with an aqueous solution containing a mixture of salts having different cations and the anions of one or more inorganic acids capable of absorbing and liberating ammonia; e.g., mixtures of different alkali metal salts of phosphoric, telluric, boric, vanadic, chromic, selenic, germanic, silicic and similar acids. Preferably the anion component will be at least one of phosphoric, chromic, or boric acids.

Abstract: Process and apparatus are described for an improved treatment of gases effluent from an ammonia phosphoric acid reactor in the manufacture of fertilizers. Ammonia is scrubbed from the gases with aqueous acid, preferably concentrated phosphoric acid, and particulates are captured and removed by contact with solid target particulates, preferably alkaline nephaline syenite. Pond water scrubbing is reduced or eliminated with improved costs and recoveries, secondary pollution is minimized, and land is conserved.

Abstract: An integrated method for the derivation of useful energy from steam containing both hydrogen sulfide and an alkaline acting component, such as ammonia, while substantially reducing the emission of sulfur-containing compounds to the atmosphere. Pretreatment of the steam to selectively remove the alkaline acting components results in the concentration of hydrogen sulfide in the uncondensed vapor as the steam is condensed during energy derivation. The uncondensed vapor is separated from the steam condensate and then is treated to produce an environmentally acceptable vent gas.

Abstract: Ammonia gas is scrubbed from a gas stream in a bed of material soaked with acid, and the bed is regenerated by passing an oxygen containing gas therethrough. The preferred acid is phosphoric acid and the preferred support material is carbon in the form of porous particles. In a fuel cell system dual scrubbers alternately scrub ammonia from reform gas and are subsequently regenerated so as to provide the fuel cells with a continuous flow of substantially ammonia free hydrogen.

Abstract: In a gas purification process wherein hydrogen sulfide is adsorbed by an alkanolamine solution in an absorption zone and desorbed in a regenerating column, the improvement comprising reducing corrosion in the overhead section of the column by introducing into the overhead section of the regenerating column an effective amount of ammonia scrubber bottoms liquid.

Abstract: A process is described for the simultaneous removal of H.sub.2 S and ammonia from gaseous streams containing other acid and basic gases. The process comprises closed loop scrubbing of the gaseous stream with a copper sulfate-ammonium sulfate solution to yield a copper sulfide precipitate, concurrent neutralization of the acidity generated in the scrubbing step by addition or scrubbing of ammonia and other basic gases, separating the precipitate, hydrothermally leaching the precipitate with oxygen or air under controlled temperature and pressure to reoxidize the sulfide to copper sulfate, recycling the copper sulfate to the scrubber, and rejecting sulfur from the system in the form of (NH.sub.4).sub.2 SO.sub.4.

Abstract: Disclosed is a wet process for efficiently and economically removing a specific gas component and/or solid component from a gas containing the same wherein the gas is countercurrently contacted with a scrubbing liquid in a perforated or grid plate column without weir and downcomer and having a free-space ratio of 0.30 to 0.60 under the conditions of a superficial gas velocity of from 1.5 to 8 m/sec and a liquid flow rate of from more than 110,000 to 250,000 kg/m.sup.2 .multidot. hr.

Abstract: Optimum concentration of the acid-scrubbing solution employed in a scrubbing tower for removal of malodorous and/or toxic gases from the air is maintained automatically in a control system which senses the electrical conductivity of the solution to control acid-feeding apparatus. High and low concentration alarms are also provided to warn of malfunction.

Abstract: An improvement in a process for regenerating a water-containing, highly volatile organic solvent which has been used to scrub acid constituents from gases having a low content of water and of volatile compounds of the 8th group of the Periodic System is disclosed. According to the process, solvent which contains absorbed acid constituents is regenerated in a regeneration zone by heating the same to drive off acid constituents and deacidified solvent is recycled in the scrubbing process. According to the invention the solvent is contacted during the regeneration with a complexing agent soluble in the solvent in an amount of 0.005 to 1 gram complexing agent per liter of solvent. A branch stream is removed from the regeneration zone which branch stream contains volatile solvent, water and metal salts dissolved in the water. The branch stream is subjected to distillation to remove overhead the volatile solvent which is returned to the regeneration zone and to leave behind an aqueous solution of the metal salt.

Abstract: Acidic gases are substantially removed from a normally gaseous mixture by a process comprising contacting the normally gaseous mixture with an amine-solvent liquid absorbent comprising (i) an amine comprised of at least about 50 mol % of a sterically hindered amine, and (ii) a solvent for said amine mixture which is also a physical absorbent for said acidic gases. The liquid absorbent may also include up to about 35 weight percent water.

Abstract: A process for the separation of ammonia from a gaseous mixture containing ammonia and hydrogen cyanide which comprises contacting said gaseous mixture in an absorption stage with an absorbent liquor comprising an acidified ammonium nitrate solution thereby selectively absorbing ammonia from said gaseous mixture and forming a solution of diminished acidity, adding nitric acid to the ammonium nitrate-containing solution of diminished acidity to restore its acidity to its initial level and recycling said restored solution to said absorption stage.

Abstract: A method and apparatus for removing ammonia nitrogen from wastewater at any given temperature. The apparatus and method includes the concept of increasing the pH of the wastewater to a highly basic condition, exposinng the wastewater to a vacuum having an absolute pressure at least approaching the vapor pressure of the wastewater proportional to the given temperature whereby ammonia gas is then desorbed from the wastewater, and subsequently absorbing the desorbed ammonia in a body of liquid having a pH substantially less than the highly basic condition of the original wastewater.

Abstract: A process for purifying gases produced by the gasification of fossil fuels by a treatment with water vapor and oxygen under superatmospheric pressure. The raw gas produced is treated to remove catalyst-deteriorating impurities such as mono- and polyunsaturated hydrocarbons, mercaptans, HCN, HCl, H.sub.2 S, CS.sub.2, COS, and NH.sub.3, and to desulfurize the gas to produce an exhaust gas which is rich in H.sub.2 S. The gas is cooled and scrubbed under superatmospheric pressures and at normal temperatures. The raw gas, at a temperature of 150.degree.-170.degree. C., is indirectly cooled to ambient temperature. The condensible hydrocarbons are then separated and removed, and the gas is then scrubbed with water to remove ammonia in a first scrubbing stage wherein the rate of water addition is controlled to be just sufficient to remove the ammonia.

Abstract: Improved reactive absorbent solutions for absorbing gaseous components are provided by incorporating weakly dissociating compounds in liquid absorbents. When the gaseous component to be dissolved is acid-forming, the absorbent solution should be alkaline, the weakly dissociated compound should be a weak acid or salt thereof, and the pH of the solution should approximate the pK.sub.A of the acid. When the gaseous component is base-forming, the liquid absorbent should be acidic, the weakly dissociating compound should be a weak base, and the pOH of the solution should approximately match the pK.sub.B of the weak base. The weakly dissociated compounds are 1 to 20 times more effective in increasing absorption rates, than additions of equivalent amounts of the primary acidic or basic reactants. Where the absorbed gas is desorbable, the addition of the weakly dissociating compounds has similar effects in increasing the rate of desorption.