This disclosure relates to improved methods for alkali metal cyanide production, particularly to improved methods for sodium cyanide production. The improved method of producing sodium cyanide involves the step of contacting hydrogen cyanide with an aqueous solution of sodium carbonate or of a mixture of sodium carbonate and sodium bicarbonate to produce a sodium cyanide solution.

A method for producing aqueous hydrochloric acid from flue gases is provided. The method comprises conveying water to a first scrubber (102, 202, 302, 402, 502, 602, 702) or to a line (112b, 212b, 312b, 412b, 512b, 712b, 712c) to use the water in a scrubbing liquid of the first scrubber. The method also comprises providing flue gas containing chlorides into the first scrubber (102, 202, 302, 402, 502, 602, 702) and scrubbing the flue gas containing chlorides with the scrubbing liquid by contacting the flue gas with the scrubbing liquid in the first scrubber (102, 202, 302, 402, 502, 602, 702). Dilute hydrochloric acid and a flue gas derivate (104, 204, 304, 404, 504, 704) are produced. The method comprises letting out at least some of the dilute hydrochloric acid from the first scrubber (102, 202, 302, 402, 502, 602, 702) as a scrubber bleed, separating solids suspended by the scrubber bleed in a solids separator (192, 592, 692), conveying the scrubber bleed from the solids separator (192, 592, 692) into an evaporation vessel (194, 594, 694) and concentrating the scrubber bleed in the evaporation vessel (194, 594, 694) to produce hydrochloric acid vapor having a concentration of 5-22 wt-%. A corresponding system is also provided.

The present invention relates to a process suitable for reducing ammonia loss and odor from organic material to the atmosphere. The process comprises feeding air to a plasma generator to produce a concentration of 0.1-12% by volume of NOx in the air by direct nitrogen fixation. Cooled air containing NOx from the plasma generator is fed to an absorption system comprising at least two absorption loops, wherein a first absorption liquid is circulating in the first absorption loop and a second absorption liquid is circulating in the second absorption loop. The air containing NOx is absorbed into the first absorption liquid to form an acidic solution comprising nitrates and nitrites. Off gases containing NO from the first absorption loop is fed to the second absorption loop, and the off gases containing NO are absorbed into the second absorption liquid having a lower pH

In a process for removal of acid gases from a fluid stream the fluid stream is contacted with an absorbent to obtain a treated fluid stream and a laden absorbent. The absorbent comprises a diluent and a compound of the general formula (I) wherein R.sup.1 is C.sub.1-C.sub.3-alkyl; R.sup.2 is C.sub.1-C.sub.3-alkyl; R.sup.3 is selected from hydrogen and C.sub.1-C.sub.3-alkyl; and R.sup.4 is selected from hydrogen and C.sub.1-C.sub.3-alkyl. ##STR00001##

Disclosed is a process for regenerating a hybrid solvent used to remove contaminants from a fluid stream and to provide an improved yield of purified fluid. Said process comprises a purification unit (12) and at least one regeneration unit (40) wherein make-up water (72) is added to the regenerated lean hybrid solvent (55) prior to reuse in the first purification unit and no water is recycled into the regeneration unit.

A process for removing hydrogen sulfide from a sour gas stream is presented. The method oxidizes hydrogen sulfide to sulfuric acid by reducing aqueous bromine to hydrobromic acid in solution. The aqueous bromine solution does not react with hydrocarbon components common to natural gas including methane and ethane. This allows the process to both sweeten sour gas and convert its hydrogen sulfide content to sulfuric acid in a single step. In the present process, sulfuric acid is concentrated to eliminate its bromine content prior to being removed from the system, while the remaining hydrobromic acid solution is electrolyzed to regenerate aqueous bromine and produce hydrogen. Hydrobromic acid electrolysis requires less than half the energy required by water electrolysis and is an inherently flexible load that can shed or absorb excess power to balance supply and demand.

A waste water processing system includes an upflow contacting column having a flue gas input for receiving flue gas having a temperature of at least 500 degrees F., a waste water input, and a flue gas output. The waste water input is coupled to a fluid injector, e.g., atomizing nozzles, positioned in the throat of a Venturi portion of the upflow contacting column or in a sidewall of the throat of the Venturi portion of the upflow contacting column. The flue gas in the upflow contacting column has a high velocity, e.g., a gas velocity exceeding 65 fps in the throat of the Venturi portion of the upflow contacting column at a position where the fluid injector is located. Drying additives such as recycled ash, lime, and/or cement may be, and sometimes are, input into the upflow contacting column downstream of the waste water input.

An aqueous liquid sorbent suitable for use in separating a target gas from a mixture of gases in a rotating packed bed gas capture system, comprising a first amine compound, a second amine compound and water, wherein the sorbent comprises at least 16 wt % of the first amine compound and at least 51 wt % of total amine compounds, the first amine compound has a reaction rate with the target gas that is greater than the reaction rate of the second amine with the target gas, and the second amine compound has a solubility in water that is greater than the solubility of the first amine compound in water.

A method for removing a halogen fluoride in a mixed gas by reacting the mixed gas containing a halogen fluoride including bromine or iodine with a removing agent, wherein the removing agent is a chloride, bromide or iodide of potassium, sodium, magnesium, calcium and barium. Also disclosed is a quantitative analysis method as well as a quantitative analyzer for a gas component contained in a hydrogen fluoride mixed gas, the method characterized by reacting a mixed gas containing a halogen fluoride and another gas component with a removing agent, thereby removing the halogen fluoride in the mixed gas, further removing produced by-products, and quantitatively analyzing a residual gas by a gas chromatograph.

The present invention concerns the field of capturing the CO.sub.2 from a gaseous effluent. The incoming gaseous effluent is burned with a fuel, so as to obtain a hot gaseous effluent rich in acidic compounds, and the hot gaseous effluent rich in acidic compounds is cooled to give a cold effluent rich in acidic compounds, which is subsequently used in the step of contacting with an absorbent solution rich in acidic compounds.