Abstract: A two stage method for reducing the sulfur content of exhaust gases is disclosed. Alkali- or alkaline-earth-based sorbent is totally or partially vaporized and introduced into a sulfur-containing gas stream. The activated sorbent can be introduced in the reaction zone or the exhaust gases of a combustor or a gasifier. High efficiencies of sulfur removal can be achieved.

Abstract: A process of removing noxious sulfur oxides from gas streams using heated layered double hydroxide (LDH) sorbents is described. The sorbent compositions contain metal components incorporated into the galleries of the LDH structures in the form of metal-containing oxo-anions, to promote the oxidation of sulfur dioxide.

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: A method for the removal of nitrogen oxides from waste gases and for obtaining nitric acid is described. The waste gas is charged with the required amount of hydrogen peroxide, converted into the gas phase, and the gas mixture is reacted on a solid catalyst to hydrogen nitrate, which is either withdrawn for further use or is converted into nitric acid either by condensation or by scrubbing with water. The method permits the removal of NO.sub.x at low concentrations below 2000 ppm with efficiencies above 90%.

Abstract: Carbon blacks having an I.sub.2 number of 135-200 and a DBP of 105-150 which, when incorporated into rubber compositions, impart increased abrasion resistance and lower hysteresis. Also disclosed are rubber compositions incorporating the novel carbon blacks.

Abstract: Flue gases etc. may contain SO.sub.2 which should be prevented from admission to the atmosphere. SO.sub.2 is oxidized to SO.sub.3 and condensed with steam to H.sub.2 SO.sub.4 -vapors which are condensed in vertical glass tubes cooled from the outside. In principle the condensate is collected near the bottom of the tubes. In the cooling process a mist of very small H.sub.2 SO.sub.4 droplets is formed and tends to escape to the atmosphere. Environmental regulations continually increase the demands on reducing the amount of acid mist escaping. According to the invention an important method to achieve a reduction of the escape of acid mist is to pass the gas leaving each tube through an aerosol filter in gastight connection with the tube top. Such a filter may consist of acid resistant fibres or filaments having a thickness of 0.04-0.7 mm and may be arranged in specified manners to ensure a drop of pressure through below 20 mbar.

Abstract: Exhaust gases are treated to remove NO or NO.sub.x and SO.sub.2 by contacting the gases with an aqueous emulsion or suspension of yellow phosphorous preferably in a wet scrubber. The addition of yellow phosphorous in the system induces the production of O.sub.3 which subsequently oxidizes NO to NO.sub.2. The resulting NO.sub.2 dissolves readily and can be reduced to form ammonium ions by dissolved SO.sub.2 under appropriate conditions. In a 20 acfm system, yellow phosphorous is oxidized to yield P.sub.2 O.sub.5 which picks up water to form H.sub.3 PO.sub.4 mists and can be collected as a valuable product. The pressure is not critical, and ambient pressures are used. Hot water temperatures are best, but economics suggest about 50.degree. C. The amount of yellow phosphorus used will vary with the composition of the exhaust gas, less than 3% for small concentrations of NO, and 10% or higher for concentrations above say 1000 ppm.

Abstract: A process and apparatus for removing SO.sub.2 from low-volume gas streams containing high concentrations of SO.sub.2 includes a tank scrubber containing an aqueous SO.sub.2 absorbent and an impeller. The impeller includes a vertical rotating shaft having an upper and lower impeller. The lower impeller serves to agitate the SO.sub.2 absorbent. The upper impeller includes a shroud thereby directing the absorbent and gas outwardly toward the wall of the scrubber. The gas is injected into the absorbent at a point below the shrouded impeller. The shroud prevents gas bypass and thereby promotes gas-liquid mixing and, consequently, markedly improves SO.sub.2 removal efficiency.

Abstract: Commercially viable processes of the SCR type for converting nitrogen oxides to nitrogen with ammonia: (a) in the presence of an iron, cobalt, nickel, or other transition metal sulfate with Bronsted activity; (b) at a temperature of not more than 250.degree. C.; and (c) preferably in a dry environment if room or near room temperatures are employed. The process may be used to eliminate nitrogen oxides from flue gases, other exhaust gases, and the like and in other applications in which the reduction of a nitrogen oxide is wanted. Excess ammonia and/or sulfur dioxide may be maintained in the reaction mixture to promote process efficiency. The catalysts have appreciable Bronsted activity even at ambient temperatures and are capable of effecting NO.sub.x conversions with efficiencies of at least 50 percent in even demanding applications at temperatures below the 250.degree. C. maximum. They can be unsupported or supported on a porous support.

Abstract: A process for the removal of carbon-containing or nitrogen oxide-containing pollutants in low-dust flue gases by catalytic reduction, which is characterized in that a reducing agent is injected through nozzle(s) into the intermediate space of one stage of the economizer, said reducing agent is mixed with the low-dust flue gas in the tube bundles of the economizer, and the resultant reduction flue gas mixture passes catalyst layers located downstream of the economizer at a local velocity greater than 6.5 m/s.

Abstract: Processes are disclosed for purifying hydrocarbon feedstreams, e.g, natural gas, to remove carbonyl sulfide and other acid gases such as carbon dioxide and hydrogen sulfide. The processes employ a conversion step to convert carbonyl sulfide to hydrogen sulfide and carbon dioxide followed by an absorption step to remove the carbon dioxide and hydrogen sulfide from the feedstream. Carbonyl sulfide is converted to carbon dioxide and hydrogen sulfide in the presence of an aqueous alkaline solution which preferably has the same composition as the absorption solution used in the absorption step.

Abstract: A dry type simultaneous desulfurization and dedusting method directed to forming moving beds with granulate desulfurizing and dedusting agent containing as the principle composition 5-95 weight % of iron oxide and 95-5 weight % of metallic iron, and contacting these moving beds with the gas containing hydrogen sulfide and dust, thereby simultaneously desulfurizing and dedusting the gas.

Abstract: The present disclosure relates to improved processes for treating acid gases to remove acid gas components therefrom. Processes in accordance with the present invention include preparing a calcium silicate hydrate sorbent in the form of a semi-dry, free-flowing powder, and treating the gas with the powdery sorbent, such as by injecting the sorbent into a stream of the gas. The powdery sorbents may be prepared by slurrying/drying or pressure hydration techniques. Examples disclosed herein demonstrate the utility of these processes in achieving improved acid gas-absorbing capabilities in both lab-scale and pilot plant studies. Additionally, disclosure is provided which illustrates preferred plant design configurations for employing the present processes using conventional dry sorbent injection equipment. Retrofit application to existing plants is also addressed.

Abstract: A method wherein a boiler stack may be retrofitted for sulfur dioxide removal with ammonium sulfite scrubbing and nitrogen oxide reduction by reaction with chelated iron, and wherein a nitrogeneous fertilizer fortified with chelated iron is produced and stored in a cooling pond for sale as a 50% solution.

Abstract: Sulfur dioxide is removed from a fluid containing SO.sub.2 by employing as an absorbent therefor an aqueous solution of compounds represented by Formulas I and II: ##STR1## wherein each R.sup.1 or R.sup.2 is independently hydrogen; an alkyl group; a hydroxyalkyl group; an aldehyde group; a carboxylic acid or salt group; an alkyl group containing at least one carboxylic ester, carboxylic acid or salt, ether, aldehyde, ketone or sulfoxide; and wherein at least one R.sup.1 or R.sup.2 is a carbonyl-containing group, such as an aldehyde group, a carboxylic acid containing group, a carboxyl ester group, or a ketone-containing group; ##STR2## wherein each R.sup.3 is independently hydrogen; an alkyl group; a hydroxyalkyl group; an aldehyde group; a carboxylic acid or salt group; or an alkyl, aryl, or aralkyl group containing at least one carboxylic ester, a carboxylic acid or salt, ether, aldehyde, ketones or sulfoxide group. The absorbent solution preferably can be thermally regenerated by heating to remove SO.sub.

Abstract: An improved process for reducing nitrogen oxide emissions to the atmosphere comprises the injection of ammonia vapor, formed by the vaporization of an aqueous ammonia solution, into a combustion effluent. A dilute aqueous ammonia phase, produced by such vaporization, may also be injected, either in vapor or liquid form, into a combustion effluent. Temperature and pressure control of such vaporization may be used to maintain the desired concentration of ammonia injected into the combustion effluent.

Abstract: Trialkyl arsine (in particular trimethyl arsine) is removed from a fluid (e.g., a hydrocarbon-containing gas) by contacting the fluid with a sorbent material comprising vanadium pentoxide (V.sub.2 O.sub.5) and an inorganic support material (preferably alumina or silica or vanadium metal).

Abstract: In a sorption bed which is formed as a fluidized bed reactor possibly with circulating fluid, or as a fixed-bed reactor, for dry waste gas or waste air, purification sorbents introduced in the dry state are contacted at a temperature range between about 30 and 130.degree. C. by the waste gas with an at least 2% oxygen content and the acidic and/or oxidizable noxious gaseous components of the waste gas are found by the sorbent. Noxious gaseous components potentially include SO.sub.x, HCl, HF, NO.sub.x, Co and also hydrocarbons. The average dwelling time of the sorbents is at least about 20 minutes, in general several hours or days, and the average grain size of sorbent is at most 125 microns. The sorbent is introduced fresh and in stoichiometric ratio, with spent sorbent being correspondingly removed. Sorbents which may be considered are primarily baking soda (sodium bicarbonate), Ca(OH).sub.2 and Mg(OH).sub.2.

Abstract: A process for removal of H.sub.2 S from sour gaseous streams by use of an aqueous reactant solution is described in which the sour gaseous stream is employed as the motive force to transport the solution during the contact phase of the process, at the same time the static head of the aqueous reactant solution in the reservoir is used to provide the solution in the reservoir to the reaction zone entrance.

Abstract: An exhaust gas containing a nitrogen oxides is passed at a temperature of 250.degree. to 550.degree. C. in the presence of a reducing agent through a catalyst bed filled with a molded denitration catalyst comprising at least the following three catalyst components(A) an oxide of at least one metallic element selected from the group consisting of Ti, Si and Zr,(B) an oxide of at least one metallic element selected from the group consisting of Mo and W, and(C) an oxide of Vsuch that the concentrations of the oxide (B) and/or the oxide (C) in the exhaust gas inlet site of the catalyst bed are higher than in the other site thereof.The molded denitration catalyst is also described.