Abstract: A process for controlling the aeration rate during the aerobic phase of a wastewater treatment process is disclosed, which comprises: (a) measuring at moment t1 the ammonium concentration [NH4+]1 and nitrogen oxide concentration [NOx]1 in a mixture of wastewater and microbial sludge; (b) determining a nitrogen oxide target concentration [NOx]F1 at the end of the aerobic phase based on at least the current ammonium concentration [NH4+]1 and the current NOx concentration [NOx]1; (c) determining a setpoint [NOx]SP1 based on interpolation between [NOx]1 and [NOx]F1; (d) adjusting the aeration rate to minimise error between [NOx]1 and [NOx]SP1; and (e) repeating steps (a) to (d) at further moments t1. The invention further concerns a process for the treatment of wastewater, using the process.

Abstract: A catalyst article for treating a flow of a combustion exhaust gas comprises: a catalytically active substrate comprising one or more channels extending along an axial length thereof through which, in use, a combustion exhaust gas flows, the one or more channels having a first surface for contacting a flow of combustion exhaust gas; wherein the substrate is formed of an extruded vanadium-containing SCR catalyst material, wherein a first layer is disposed on at least a portion of the first surface, wherein the first layer comprises a washcoat of an ammonia slip catalyst composition comprising one or more platinum group metals supported on a particulate metal oxide support material, and wherein a layer comprising a washcoat of SCR catalyst composition is disposed on a surface in the one or more channels, wherein at least the portion of the first surface on which the first layer is disposed comprises a compound of copper, iron, cerium or zirconium or a mixture of any two or more thereof.

Abstract: A method for cleaning an off-gas from viscose production, essentially containing H2S and CS2, comprises passing the gas through a catalytic reactor containing a direct oxidation type catalyst, such as V2O5 on silica, to convert H2S in the gas to elemental sulfur, SO2 or mixtures thereof, either via the oxygen present in the gas or via oxygen added to the gas stream. Elemental sulfur and SO2 are removed from the effluent gas from the catalytic reactor, and the unconverted CS2 is recycled to the viscose production process.

Abstract: Provided is a catalyst including: a support including titanium oxide; an active catalyst component including vanadium oxide; and a co-catalyst including antimony and cerium, in which the catalyst is included in a deNox reduction reaction that decomposes nitrogen oxide. The catalyst may improve sulfur poisoning tolerance characteristics while improving the deNox efficiency at a temperature in a wide range from low temperature to high temperature.

Abstract: A catalyst article for treating a flow of a combustion exhaust gas comprises: a catalytically active substrate comprising one or more channels extending along an axial length thereof through which, in use, a combustion exhaust gas flows, the one or more channels having a first surface for contacting a flow of combustion exhaust gas; wherein the substrate is formed of an extruded vanadium-containing SCR catalyst material, wherein a first layer is provided on at least a portion of said first surface, wherein the first layer comprises an ammonia slip catalyst composition comprising one or more platinum group metals supported on titania, a silica-titania mixed oxide, a Ce—Zr mixed oxide, or a mixture thereof, and a second layer is provided on at least a portion of the first layer and comprises an SCR catalyst composition.

Abstract: An exhaust purification device for an engine facilitates thawing of a urea aqueous solution, which is frozen in a reducing agent tank of an exhaust purification device, more rapidly. When a urea aqueous solution in a reducing agent tank is frozen at a time of starting an engine, at least a part of the urea aqueous solution to be supplied to an injection nozzle is flown into a reducing agent circulation flow path, a part of which is adjacent to a heat source, and the urea aqueous solution thus heated is returned to the reducing agent tank.

Abstract: A catalyst for direct decomposition of NO and NO2 to N2 and O2 has a CoFe2O4 spinel doped with potassium cations. The catalyst has high activity and good selectivity for N2 production, when potassium cations are loaded at a density of about 0.9 weight percent. Methods for making the catalyst include wet impregnation of a CoFe2O4 spinel with a solution of potassium cations, such as a KOH solution.

Abstract: In one embodiment, a membrane of proton-electron conducting ceramics that is useful for the conversion of a hydrocarbon and steam to hydrogen has a porous support coated with a film of a Perovskite-type oxide. By including the Zr and M in the oxide in place of Ce, the stability can be improved while maintaining sufficient hydrogen flux for efficient generation of hydrogen. In this manner, the conversion can be carried out by performing steam methane reforming (SMR) and/or water-gas shift reactions (WGS) at high temperature, where the conversion of CO to CO2 and H2 is driven by the removal of H2 to give high conversions.

Abstract: A method of making a filter for filtering particulate matter from exhaust gas emitted from a lean-burn internal combustion engine, which filter comprising a porous substrate having inlet surfaces and outlet surfaces, wherein the inlet surfaces are separated from the outlet surfaces by a porous structure containing pores of a first mean pore size, wherein the inlet surfaces comprise a bridge network comprising interconnected particles of refractory material over the pores of the porous structure, which method comprising the step of contacting inlet surfaces of the filter substrate with an aerosol comprising refractory material in dry powder form. The invention also relates to a filter obtainable by such method.

Abstract: A hydrogen generator that can be operated in a broad temperature range is disclosed, which comprises a first ammonia conversion part having a hydrogen-generating material which reacts with ammonia in a first temperature range so as to generate hydrogen; a second ammonia conversion part having an ammonia-decomposing catalyst which decomposes ammonia into hydrogen and nitrogen in a second temperature range; an ammonia supply part which supplies ammonia; and an ammonia supply passage which supplies ammonia from said ammonia supply part to the first and second ammonia conversion parts. The first temperature range includes temperatures lower than the second temperature range, and hydrogen is generated from ammonia by selectively using the first and second ammonia conversion parts. An ammonia-burning internal combustion engine and a fuel cell having the hydrogen generator are also disclosed.

Abstract: A method of making a filter for filtering particulate matter from exhaust gas emitted from a lean-burn internal combustion engine, which filter comprising a porous substrate having inlet surfaces and outlet surfaces, wherein the inlet surfaces are separated from the outlet surfaces by a porous structure containing pores of a first mean pore size, wherein the inlet surfaces comprise a bridge network comprising interconnected particles of refractory material over the pores of the porous structure, which method comprising the step of contacting inlet surfaces of the filter substrate with an aerosol comprising refractory material in dry powder form. The invention also relates to a filter obtainable by such method.

Abstract: Provided is an ammonia detoxification device that, when detoxifying ammonia by thermal decomposition, is capable of preventing the generation of nitrogen oxides. That is, the problem is solved by configuring the ammonia detoxification device using: an electric heater; an ammonia decomposition chamber that accepts an ammonia-containing gas to be treated and thermally decomposes the ammonia in the absence of oxygen using heat from the electric heater; a thermally decomposed gas-burning chamber that accepts the nitrogen- and hydrogen-containing gas to be treated that has been generated by the thermal decomposition of the ammonia and discharged from the ammonia decomposition chamber, and an air-supplying means for supplying air from the outside into the thermally the thermally decomposed gas-burning chamber to burn the hydrogen.

Abstract: This invention relates to a process for incinerating NH3 in an NH3 incinerator comprising a first incineration step at controlled sub-stoichiometric incineration conditions and a second incineration step with at a greater than stoichiometric amount of oxygen, whereby a product stream is produced with reduced NO formation. The invention also relates to an NH3 incinerator.

Abstract: An acid-impregnated activated carbon matrix is formed from a carbonaceous material by the addition of a mineral acid, and may be used to chemisorb ammonia from a gas stream. The ammonia reacts with the acid to form a fertilizer salt. The spent matrix may be used as a fertilizer, or the fertilizer salt may be elutriated from the matrix.

Abstract: A catalyst system may include a three-way catalyst that receives exhaust gases from an engine and an ammonia slip catalyst that receives exhaust gases from the three-way catalyst. An air injection component can be configured between the three-way catalyst and the ammonia slip catalyst. A first sensor can determine first exhaust gases data and transmits that data to a controller, while a second sensor can determine second exhaust gases data and transmit that data to a controller. The controller can estimate unmeasured exhaust gases data based on the data received from the sensors and determine a setting of a component of the system and/or of the engine based on the unmeasured exhaust gases data.

Abstract: An ammonia recovery system and method for removing ammonia from a gas stream is provided. The system includes an ammonia recovery vessel for contacting a solution, having a dissolved acidic salt, with the gas stream, having ammonia. The dissolved acidic salt solution absorbs the ammonia in the gas stream to provide an ammonia-lean gas stream and an ammonia-rich solution. The ammonia-rich solution is heated within an ammonia stripper to release the ammonia from the ammonia-rich solution to thereby generate an ammonia-rich gas stream and the solution having dissolved acidic salt. A heat exchanger heats the dissolved acidic salt from the ammonia stripper prior to the solution being provided to the ammonia recovery system. The acidic salt has a low thermal decomposition.

Abstract: A method for removing ammonia from a gas stream divides the gas steam into a plurality of separate gas streams and sprays a dilute acid solution into the streams. The acid solution is aqueous sulfuric acid and ammonium sulfate is produced. A device is used to divide the gas stream, the device having a plurality of conduits in fluid communication with a plenum. Spray nozzles are located in each conduit to spray the acid solution into the gas streams. The device creates less than 10 Pa back pressure to the gas stream.

Abstract: A compacted block of material constructed of one or more units consisting of matter comprising an ammonia-saturated material capable of reversibly desorbing and ad- or absorbing ammonia surrounded by a gas-permeable, flexible material having a thermal conductivity of at least five times the thermal conductivity of said ammonia-saturated material at ?70° C. to 250° C. and methods for producing the same are described.

Abstract: A catalyst article for treating an emission gas is provided comprising (a) an oxidation catalyst comprising at least one noble metal on a WO3—TiO2 support, wherein the support contains about 1 to about 20 weight percent WO3 based on the combined weight of the WO3 and TiO2; and (b) a substrate, wherein the first and second catalyst layers are on and/or within the substrate.

Abstract: This invention relates to processes for the selective removal of contaminants from effluent gases. More particularly, various embodiments of the present invention relate to selective removal and recovery of sulfur dioxide from effluent gases in a regenerative sulfur dioxide absorption/desorption process that achieves favorable energy efficiency. Energy is recovered from a wet stripper overhead gas stream produced in the desorption cycle by indirect transfer of heat from the stripper gas to a cooling medium and used to generate steam for use in stripping contaminants from the absorption liquor. The absorption zone may optionally be cooled to enhance the capacity of the absorption medium for absorption of a contaminant gas, thereby lowering the volume of absorption medium and contaminant-enriched absorption liquor that must be pumped, handled, heated and cooled in the absorption/desorption cycle.

Abstract: Systems and Methods for manufacturing ZPGM catalysts systems that may allow the prevention of formation or the conversion of corrosion causing compounds, such as hexavalent chromium compounds, within ZPGM catalyst systems are disclosed. ZPGM catalysts systems, may include metallic substrate, which may include alloys of iron and chromium, a washcoat and an overcoat. Disclosed manufacturing processes may include a thermal decomposition of hexavalent chromium compounds which may allow the decomposition of such compounds into trivalent chromium compounds, and may also produce metallic catalyst, such as silver.

Abstract: One embodiment includes an oxidation catalyst assembly formed by applying a washcoat of platinum and a NOx storage material to a portion of a substrate material.

Abstract: A system and method for passive capture of ammonia in an enclosure containing material that gives off ammonia. The invention allows for the passage of gaseous NH3 through microporous hydrophobic gas-permeable membranes and its capture in a circulated acidic solution with concomitant production of a concentrated non-volatile ammonium salt.

Abstract: There are provided methods capable of easily and efficiently recovering and recycling ammonia from exhaust gas containing a small amount of ammonia, the exhaust gas being exhausted from a production process of a gallium nitride compound semiconductor. The method of recovering ammonia includes filtering exhaust gas containing ammonia, hydrogen, nitrogen, and a solid compound with a filter to remove the solid compound from the exhaust gas; pressurizing and cooling the filtered exhaust gas with a heat pump to liquefy ammonia contained in the filtered exhaust gas; and separating liquefied ammonia from hydrogen and nitrogen to recover liquefied ammonia. The method of recycling ammonia includes evaporating recovered liquid ammonia; mixing the evaporated ammonia with another crude ammonia to obtain mixed gas; purifying the mixed gas; and supplying the purified gas to the production process of a gallium nitride compound semiconductor.

Abstract: A catalytic reactor (16) is provided for purposes of effecting therewith the removal of nitrogen oxides from a process gas (F) that includes at least two catalyst bed segments (48, 50, 52), each of which is provided with a closing device (60, 62, 64). The catalytic reactor (16) is operative for causing said process gas (F) to flow through a first catalyst bed segment (48). Said process gas (F) is at a first temperature at which the sulphur trioxide that is entrained in said hot process gas is at least partially precipitated out on to the catalytic material that said first catalyst bed segment (48) embodies. Periodically said closing device (60) is operated in order to thereby isolate said first bed segment (48) from the flow therethrough of said hot process gas (F). A regeneration system (34, 36, 38) is also provided that is operative for purposes of causing a regenerating gas to flow through the first bed segment (48).

Abstract: Combustion flue gas containing NOX and SOX is treated to remove NOX in a multistep system in which NOX is reduced in the flue gas stream via selective catalytic reduction or selective non-catalytic reduction with ammonia or an ammonia-forming compound, followed treatment with hydrogen peroxide to remove residual ammonia and, optionally, treatment with an alkali reagent to reduce residual NOX in the flue gas stream. The NOX-depleted flue gas stream may also be subjected to a desulfurization treatment for removal of SOX.

Abstract: The present invention relates to methods and systems for improving the utilization of energy in a cement manufacturing plant comprising an absorption based contaminant, e.g. CO2, capture process using thermal regeneration of a liquid absorbent. The methods and systems of the present invention are characterized in that the thermal regeneration of the liquid absorbent is at least partially effected using a hot exhaust gas stream generated in the kiln of the cement manufacturing plant.

Abstract: This invention relates to a process for incinerating NH3 in an NH3 incinerator comprising a first incineration step at controlled sub-stoichiometric incineration conditions and a second incineration step with at a greater than stoichiometric amount of oxygen, whereby a product stream is produced with reduced NO formation. The invention also relates to an NH3 incinerator.

Abstract: Disclosed herein is a process and a plant for recovering ammonia from a mixture including ammonia, acid gas containing H2S and/or CO2 and low-boiling water-soluble organic components. To avoid an enrichment of volatile organic compounds in the acid gas absorber, a partial stream of the liquid phase is withdrawn from an acid gas absorber and processed such that gaseous ammonia with a reduced content of volatile organic components is obtained, which is recirculated into the acid gas absorber.

Abstract: A process for treating a milled product to reduce microbial activity at a high confidence level is disclosed. A sterile ready to eat milled product at a high confidence of sterility is also disclosed.

Abstract: For the purification of waste gas containing nitrogen oxides in combination with CO, VOCs or nitrous oxide, in particular waste gas resulting from the production of cement clinker, nitric acid, adipic acid, fertilizers and uranium trioxide, a regenerative thermal post-combustion system with at least two regenerators (A, B) is used by means of which the CO, VOCs and nitrous oxide are thermally purified in the combustion chamber (1) at a temperature of 800 to 1000° C. and the nitrogen oxides are thermally reduced with the SCR catalyst (6) by adding a nitrogen-hydrogen compound, wherein the waste gas already thermally purified is removed from the respective two-part regenerator (A or B) at a suitable place at a temperature of approx. 300° C., guided via the SCR catalyst (6) in a constant direction of flow and subsequently fed back to the remaining section (A?, B?) of the regenerator (A or B).

Abstract: A catalyst article for treating an emission gas is provided comprising (a) a first catalyst layer having a plurality of consecutive sub-layers, wherein each sub-layer includes vanadium on a first refractory metal oxide support selected from alumina, titania, zirconia, ceria, silica, and mixtures of these; (b) a second catalyst layer comprising one or more noble metals disposed on a second refractory metal oxide support; and (c) a substrate, wherein the first and second catalyst layers are on and/or within the substrate.

Abstract: An adsorbent material comprising a porous inorganic oxide material grafted with a molecule comprising a carbonyl functional group is provided. The porous inorganic oxide material can be a porous silica material or Zr(OH)4. The adsorbent material can be a synthesized by grafting an organosilane molecule containing the carbonyl functional group onto the porous inorganic oxide material. The porous inorganic oxide material can be grafted with a second molecule comprising an amine functional group. Methods of making the adsorbent material and methods of removing molecules from a fluid using the adsorbent material are also provided.

Abstract: The present invention provides a method of treating an off-gas stream (80) comprising NH3 and H2S to provide a sulphate stream (910), the method comprising the steps of: (i) providing a first off-gas stream (80) comprising NH3, H2S, CO2 and optionally one or more of HCN, COS and CS2; (ii) passing the first off-gas stream (80) to an incinerator (300) to oxidize NH3, H2S, and optionally one or more of HCN, COS and CS2 to provide a second off-gas stream (310) comprising N2, H2O, SO2 and CO2; (iii) scrubbing the second off-gas stream (310) with a first aqueous alkaline stream (380, 876a) in a caustic scrubber (350) to separate SO2 and a part of the CO2 from the second off-gas stream to provide a spent caustic stream (360) comprising carbonate and one or both of sulphite and bisulphite and a caustic scrubber off-gas stream (370) comprising N2 and CO2; and (iv) passing the spent caustic stream (360) to an aerator (900) comprising sulphur-oxidizing bacteria in the presence of oxygen to biologically oxidize sulphite

Abstract: A process for dewatering biomass material comprising polysaccharide and water. The process comprises wetting the biomass material with a wetting composition comprising an alcohol to form a biomass slurry comprising wetted biomass material and a liquid component, mechanically separating a portion of the liquid component from the biomass slurry, and mechanically separating at least a portion of the water from the wetted biomass material. A process for extracting polysaccharide from the biomass material and a dewatered biomass material are also disclosed.

Abstract: The invention relates to a method for reducing aerosol emissions from a urea granulation plant with a recovery of the resulting scrubber bleeds, with a granulator producing urea from a concentrated urea solution and an evaporation of the included water, giving urea granulates and an exhaust of dust, ammonia and ammonium cyanate, and a following scrubbing or removing stage for the dust, and a following scrubbing acid stage, resulting in a first stream comprising mainly aerosols and a second stream comprising ammonium salts, and a following aerosol stage with spray and collection devices, releasing a first stream of an exhaust of air, and a second stream of ammonium cyanate and water, and the second stream of the aerosol stage of ammonium cyanate and water is recovered into the urea granulation plant or into a urea fertilizer plant.

Abstract: A process for the recovery of ammonia contained in a gaseous stream is described, said process comprising the following phases: (a) subjecting the gaseous stream containing ammonia to a washing (S) with an aqueous washing solution (5a) having a pH lower than 7.0, with the formation of a purified gaseous stream (6) and an aqueous solution (7) containing an ammonium salt; (b) subjecting the aqueous solution containing the ammonium salt coming from phase (a) to a distillation process (MD) with a hydrophobic microporous membrane at a temperature ranging from 50 to 250° C. and a pressure ranging from 50 KPa to 4 MPa absolute with the formation of a regenerated washing solution (16) and a gaseous stream (18) comprising NH3 and H2O; (c) recycling said generated washing solution to phase (a). The equipment for carrying out the above process is also described.

Abstract: Provided are catalysts comprising a small pore molecular sieve embedded with platinum group metal (PGM) and methods for treating lean burn exhaust gas using the same.

Abstract: An apparatus for recycling exhaust gas includes a vessel containing a reversible ammonia sorber material which is exothermic when sorbing (“loading”) ammonia and which is endothermic when releasing (“unloading”) ammonia. A first valve selectively couples a source of exhaust gas including ammonia to a first port of the vessel, a second valve selectively couples a vacuum pump to the vessel, and a third valve selectively coupling a second port of the vessel to an output. A controller opens and closes the first valve, the second valve and the third valve to implement a loading phase, an intermediate venting phase and an unloading phase for the vessel.

Abstract: This disclosure provides methods of making an enhanced activity nanostructured thin film catalyst by radiation annealing, typically laser annealing, typically under inert atmosphere. Typically the inert gas has a residual oxygen level of 100 ppm. Typically the irradiation has an incident energy fluence of at least 30 mJ/mm2. In some embodiments, the radiation annealing is accomplished by laser annealing. In some embodiments, the nanostructured thin film catalyst is provided on a continuous web.

Abstract: Provided is a catalyst article for treating an emission gas comprising (a) a noble metal catalyst layer comprising one or more noble metals disposed on a first refractory metal oxide support; and (b) a vanadium catalyst layer comprising vanadium pre-fixed on a second refractory metal oxide support selected from alumina, titania, zirconia, ceria, silica, and mixtures of these, wherein the first catalyst layer is in physical contact with said second catalyst layer. Also provided is a method for making such a catalyst article, a method for treating gas emissions using such an article, and an emission gas treatment system incorporating such an article.

Abstract: A process for producing soda ash from brine waste, the process including reacting brine waste with carbon dioxide and ammonia to produce soda ash, where in at least a portion of the ammonia is regenerated from the ammonium chloride produced during the reaction, the regeneration ideally be achieved by the use of a weak base anion exchange resin.

Abstract: An exhaust gas treatment apparatus comprises an ammonia absorption system and an ammonia conversion system. The ammonia absorption receives ammonia-containing tail gas generated by a semiconductor process, and removes dust from the tail gas, absorbs and decomposes ammonia gas from the tail gas, converts the ammonia gas into aqueous ammonia, and emits the tail gas without the dust and the ammonia to an external environment. The ammonia conversion system receives the ammonia solution from the ammonia absorption system, and converts it into gaseous ammonia, and then converts the gaseous ammonia to produce liquid ammonia by vaporization and cooling-pressurized liquefaction. After that, the liquid ammonia is purified by a purification system to formed hi-purity liquid ammonia.

Abstract: A system for reducing ammonia (NH3) emissions includes (a) a first component comprising a first substrate containing a three-way catalyst, wherein the first component is disposed upstream of a second component comprising a second substrate containing an ammonia oxidation catalyst, wherein said ammonia oxidation catalyst comprises a small pore molecular sieve supporting at least one transition metal; and (b) an oxygen-containing gas input disposed between the components. For example, a CHA Framework Type small pore molecular sieve may be used. A method for reducing NH3 emission includes introducing an oxygen-containing gas into a gas stream to produce an oxygenated gas stream; and exposing the oxygenated gas stream to an NH3 oxidation catalyst to selectively oxidize at least a portion of the NH3 to N2. The method may further include the step of exposing a rich burn exhaust gas to a three-way catalyst to produce the gas stream comprising NH3.

Abstract: The invention relates to the use of aqueous guanidinium formiate solutions, optionally combined with urea and/or ammonia and/or ammonium salts, for the selective catalytic reduction of nitrogen oxides using ammonia in exhaust gases of vehicles. The inventive guanidinium formiate solutions enable a reduction of the nitrogen oxides by approximately 90%. Furthermore, said guanidinium formiate solutions can enable an increase in the ammonia forming potential from 0.2 kg, corresponding to prior art, up to 0.4 kg ammonia per liter of guanidinium formiate, along with freezing resistance (freezing point below ?25° C.). The risk of corrosion of the inventive guanidinium formiate solutions is also significantly reduced compared to that of solutions containing ammonium formiate.

Abstract: Apparatus, methods and systems reside in the decomposition of ammonia into a hydrogen-containing product mixture. An ammonia-rich gaseous mixture containing ammonia and oxygen enters a conduit, within which combustion and decomposition of the mixture is initiated, thereby liberating hydrogen. A mixture of products, resulting from the reactions, is expelled from the outlet of the conduit, the mixture including non-combusted hydrogen gas, which may then be used for other purposes. The incoming reactants, including ammonia and oxygen, are heat exchanged with the outgoing product mixture containing non-combusted hydrogen gas.

Abstract: A process for the catalytic removal of hydrogen cyanide, formic acid and formic acid derivatives from synthesis gas comprising these compounds, carbon monoxide and hydrogen, the process comprising contacting the synthesis gas with a catalyst comprising one or more metals selected from the group consisting of silver, gold, copper, palladium, platinum and their mixtures and supported on a carrier comprising at least one of the oxides of scandium, yttrium, lanthanum, cerium, titanium, zirconium, aluminum, zinc, chromium and molybdenum.

Abstract: The invention relates to a process for finally removing sulphur-containing, nitrogen-containing and halogen-containing impurities contained in a synthesis gas, said process including: a) a joint step for hydrolysing COS and HCN contained in the gas and for collecting the halogen-containing compounds, using a TiO2-based catalyst, b) a washing step using a solvent, c) a step for desulphurization on a collecting or adsorbing mass. The synthesis gas purified in accordance with the process of the invention contains less than 10 ppb by weight, less than 10 ppb by weight of nitrogen-containing impurities and less than 10 ppb by weight of halogen-containing impurities.

Abstract: A method of converting nitrogen oxides in a gas to nitrogen by contacting the nitrogen oxides with a nitrogenous reducing agent in the presence of a zeolite catalyst containing at least one transition metal, wherein the zeolite is a small pore zeolite containing a maximum ring size of eight tetrahedral atoms, wherein the at least one transition metal is selected from the group consisting of Cr, Mn, Fe, Co, Ce, Ni, Cu, Zn, Ga, Mo, Ru, Rh, Pd, Ag, In, Sn, Re, Ir and Pt.

Abstract: The methods are utilized to recover ammonium from waste water using CO2 acidified absorption water. The process is particularly suited for utilization of cellular matter and a CO2 rich tail gas from a syngas fermentation process and derives significant benefit from the recovery of ammonium bicarbonate and ammonium carbonate. Ammonia and ammonium are recovered from the treatment of the syngas as an ammonium rich solution, at least a portion of which is recycled to the fermentation zone to aid in the production of liquid products. A carbon dioxide rich gas produced by fermentation is used to capture the ammonia and ammonium, forming the ammonium rich solution.