Abstract: A process and a plant for producing nitric acid involves oxidizing ammonia in the presence of catalysts to provide nitrogen monoxide-containing process gas in an oxidation reactor. The formed nitrogen monoxide may be supplied with oxygen-containing gas, and nitrogen monoxide is oxidized to provide nitrogen dioxide that is reacted with water in an absorption apparatus to give nitric acid, nitrous acid, and/or solutions of nitrates and/or nitrites. Oxidation of the nitrogen monoxide may be effected in an additional reactor positioned between the oxidation reactor and the absorption apparatus and traversed by the process gas. The oxidation of the nitrogen monoxide may be effected in an additional reactor parallel and connected to the absorption apparatus and traversed by the process gas. The disclosed processes and plants feature a high energy efficiency combined with a simple construction, and existing plants are easily upgradeable.

Abstract: A method is disclosed for obtaining dinitrogen monoxide by stepwise reduction of nitrates and/or nitrites from substances containing nitrate and/or nitrite, the reduction reaction being interrupted or limited after the step in which the dinitrogen monoxide is formed and the dinitrogen monoxide produced in the reduction reaction being separated, captured and/or collected.

Abstract: A graphite material suitable as an electrode material for non-aqueous electrolytic secondary batteries; a method for producing the same and a carbon material for battery electrodes; and a secondary battery. The graphite material includes crystallite graphite particles wherein an oxygen amount (a) (mass %) in a region from a particle surface of the graphite material to a depth of 40 nm is within a range of 0.010?(a)?0.04 as determined by a peak intensity of O1s obtained by HAX-PES measurement using a hard X-ray of 7,940 eV.

Abstract: A process for reducing nitrogen dioxide (NO2) to nitric oxide (NO) in a NO2-containing gaseous stream is provided. The process includes contacting the gaseous stream (12) with a catalyst system (28) comprising a catalyst selected from a platinum group metal. The contacting is done in the presence of carbon monoxide (22) and an organic compound (24), which synergistically improves NO2 reduction efficiency, particularly at low operating temperatures.

Abstract: A non-stoichiometric perovskite oxide having the general chemical formula LaXMnOY, in which the molar ratio of lanthanum to manganese (“X”) ranges from 0.85 to 0.95, can be used in particle form as an oxidation catalyst to oxidize NO to NO2 in an exhaust aftertreatment system for a hydrocarbon-fueled engine. The oxygen content (“Y”) fluctuates with variations in the molar ratio of lanthanum to manganese but generally falls somewhere in the range of 3.0 to 3.30. The crystal lattice adjustments spurred by the non-stoichiometric molar ratio of lanthanum to manganese are believed responsible for an enhanced NO oxidative activity relative to similar perovskite oxides with a higher molar ratio of lanthanum and manganese.

Abstract: Ammonia oxidizers are disclosed that can include gas distributors and distribution rings to improve the distribution of the flow of a gas feedstream across a catalyst bed in the ammonia oxidizer. The gas distributors include circular plates that have holes through which the gas feedstream is distributed across the catalyst bed. In some examples, the gas distributors also have a sidewall. The distribution rings are attached to the inner wall of the ammonia oxidizer at a predetermined distance below the gas distributor.

Abstract: A method for catalytic oxidation of NO to NO2 in the sulfur-containing exhaust gases of lean-burn engines, such as diesel engines is disclosed. The catalysts are oxide perovskites with a credible likelihood of being sulfur-tolerant.

Abstract: The oxidation of nitrogen oxide (NO) in an oxygen-containing exhaust gas flow from a diesel or other lean-burn engine may be catalyzed using particles of co-precipitated and calcined manganese (Mn), cerium (Ce) and zirconium (Zr) mixed oxides. In preferred embodiments, the molar ratios of Mn, Ce and Zr to the total amount of base metals in the ternary mixed oxide catalyst are in the range of 0.25-0.35, 0.40-0.50 and 0.20-0.25, respectively. Further, this ternary mixed oxide catalyst is less susceptible to sulfur poisoning than previously-disclosed binary mixed oxide catalysts. The ternary mixed oxide catalyst may also be regenerated—and the inhibiting effect of SO2 reversed—by briefly exposing the catalyst to a reducing exhaust gas environment.

Abstract: A metal fiber based on one or several elements from the group of platinum, palladium, rhodium, ruthenium, and iridium with 0 to 30% by weight of one or several additional alloy elements from the group of nickel, cobalt, gold, rhenium, molybdenum, and tungsten, contains 1 to 500 ppm by weight of boron or phosphorus. A non-woven material or netting, in particular for the production of nitrogen oxide or for the production of hydrocyanic acid, is made of such fibers. For the production of fibers based on noble metals having up to 30% by weight of additional alloy metals by drawing the fibers from a melt, the melting point of the metal is reduced by at least 400° C., before drawing of the fibers, by additionally alloying with boron or phosphorus, and the boron or the phosphorus is removed again from the fibers.

Abstract: A catalyst charge for ammonia oxidation, including the Andrussow process, comprises a first stage ammonia oxidation catalyst capable of oxidizing 20 to 99% of designed ammonia throughput, to produce a first stage product gas comprising unreacted ammonia, oxygen and nitrogen oxides, and a second stage ammonia oxidation catalyst capable of completing the oxidation of unreacted ammonia. Low levels of nitrous oxide are produced an extended campaign lengths may be seen.

Abstract: Described is a catalyst comprising a substrate and a catalyst coating of two or more layers: (a) a first layer comprising Pt and/or Pd on the substrate; and (b) a second layer comprising Pt on the first layer; these layers each further comprising: one or more particulate support materials; one or more oxygen storage component (OSC) materials; and one or more nitrogen oxide storage materials comprising one or more elements selected from the group of alkali and/or alkaline earth metals, wherein the total amount of alkali and alkaline earth metals ranges from 0.18 to 2.5 g/in3 calculated as the respective alkali metal oxides M2O and alkaline earth metal oxides MO. Also described is a method for the production of a catalyst, as well as a process for the treatment of a gas stream comprising nitrogen oxide, in particular of an exhaust gas stream resulting from an internal combustion engine.

Abstract: The present invention relates to a catalyst for removing NOx contained in exhaust gas, more specifically to a catalyst for removing NOx using metal titanate as a support. The catalyst for removing NOx according to the present invention allows metal titanate to act as a support as well as an adsorption and storage agent (hereafter an adsorption/storage agent) of NOx in lean-burn conditions. Supported noble metals or transition metal components provide a catalyst function which helps adsorption/storage by oxidizing NOx into NO2 in lean-burn conditions and participates in the reaction of reducing the adsorbed and stored NO2 into N2 in fuel-rich conditions. The catalyst according to the present invention has twice the NOx storage amount of conventional catalysts, for example Ba, and enables effective removal even in operational conditions of a wider range than 150˜700° C.

Abstract: A metal fiber based on one or several elements from the group of platinum, palladium, rhodium, ruthenium, and iridium with 0 to 30% by weight of one or several additional alloy elements from the group of nickel, cobalt, gold, rhenium, molybdenum, and tungsten, contains 1 to 500 ppm by weight of boron or phosphorus. A non-woven material or netting, in particular for the production of nitrogen oxide or for the production of hydrocyanic acid, is made of such fibers. For the production of fibers based on noble metals having up to 30% by weight of additional alloy metals by drawing the fibers from a melt, the melting point of the metal is reduced by at least 400 ° C., before drawing of the fibers, by additionally alloying with boron or phosphorus, and the boron or the phosphorus is removed again from the fibers.

Abstract: A bioreactor designed to produce N2O from organic nitrogen and/or reactive nitrogen in waste is coupled to a hardware reactor device in which the N2O is consumed in a gas phase chemical reaction, e.g., catalytic decomposition to form oxygen and nitrogen gas. Heat from the exothermic reaction may be used to generate power. The bioreactor may use communities of autotrophic microorganisms such as those capable of nitrifier denitrification, ammonia oxidizing bacteria, and/or ammonia oxidizing archaea. A portion of the N2O dissolved in aqueous effluent from the bioreactor may be separated to increase the amount of gas phase N2O product. The amount of the gas phase N2O in a gas stream may also be concentrated prior to undergoing the chemical reaction. The N2O may alternatively be used as an oxidant or co-oxidant in a combustion reaction, e.g., in the combustion of methane.

Abstract: Various methods and systems for augmenting the amount of NOX in the exhaust of an exhaust flow simulation system. These methods and system can be “combustion” or “post combustion”. A combustion embodiment injects a nitrogen-containing compound (doping agent) into the burner, so that it mixed and combusted with the fuel.

Abstract: A hydrocarbon trap comprises an Ag-zeolite which is heated by a unique steaming regimen.

Abstract: Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

Abstract: A non-chrome, copper-containing catalyst, Cu—Al—O and method of preparing the same are provided wherein the Cu—Al—O catalyst is prepared by the co-precipitation of copper nitrate (Cu(NO3)2) and sodium aluminate (Na2Al2O4) solutions using sodium carbonate (Na2CO3) as a precipitant. The precipitate is filtered, washed to removed excess sodium, and dried. The dried product, to be used in a powder form, is calcined at a preferred temperature of approximately 700° to 900° C. for approximately 1 to 4 hours. The dry powder, to be tableted or extruded, is calcined at a temperature of approximately 400° to 700° C. The activity of the Cu—Al—O catalyst can be promoted in hydrogenolysis applications by the addition of various agents. The Cu—Al—O catalyst can be employed in applications in place of Cu/Cr, or other copper based catalysts.

Abstract: Nitric oxide (NO) is oxidized into nitrogen dioxide (NO2) by the high temperature decomposition of a hydrogen peroxide solution to produce the oxidative free radicals, hydroxyl and hydroperoxyl. The hydrogen peroxide solution is impinged upon a heated surface in a stream of nitric oxide where it decomposes to produce the oxidative free radicals. Because the decomposition of the hydrogen peroxide solution occurs within the stream of the nitric oxide, rapid gas-phase oxidation of nitric oxide into nitrogen dioxide occurs.

Abstract: A method for removing NOX from gas streams emanating from stationary combustion sources and manufacturing plants utilizes the injection of hydrogen peroxide into the gas stream for rapid gas-phase oxidation of NO to NO2 and water-soluble nitrogen acids HNO2 and HNO3. The nitrogen acids may be removed from the oxidized gas stream by wet scrubbing or by contact with a particulate alkaline material to form a nitrite/nitrate salt.

Abstract: The present invention is a reactive adsorption process for separating NOx (NO and NO2/N2O4) from N2O in a mixture. The process comprises (A) selectively converting NO to NO2/N2O4 in a mixture with an oxidant and (B) selectively adsorbing NO2/N2O4 from the mixture by an adsorbent and © recovering a stream of N2O having a substantially reduced NOx concentration. The adsorbed NOx can be recovered from the adsorbent by elevated temperature, reduced pressure, inert gas purge, water wash or any combination thereof.

Abstract: A process is provided for the catalytic removal of polycyclic aromatic nitro, nitroso and/or amino compounds from the exhaust gas of a combustion system, in particular a diesel engine. The exhaust gas is brought into contact with a catalytic converter which includes a catalytically active material that contains titanium dioxide, at a temperature of from 150 to 600° C. The polycyclic aromatic compounds are oxidized at the catalytic converter through the use of oxygen to form nitrogen oxides, carbon dioxide and water.

Abstract: The invention relates to compositions of matter that can be used in NOx reduction. The compositions include non-zeolitic materials such as Group IIIB metal oxides which have high surface areas to promote high catalytic activity. In particular, the compositions have high surface areas comprise agglomerates of nanocrystalline metal oxide particles. The invention also provides methods for making these compositions and for using these compositions to reduce NOx compounds without a need for toxic reducing agents such as ammonia.

Abstract: The invention discloses a method for converting methane to higher order hydrocarbons. This method includes synthesizing ammonia from natural gas and nitrogen in the presence of a source of hydrogen. The ammonia is converted to nitrous oxide in the presence of a source of oxygen. Methane is coupled in the presence of the nitrous oxide to provide higher hydrocarbons. The invention also discloses a method of balancing reaction heat requirements in a process for converting methane to higher order hydrocarbons.

Abstract: A method and apparatus for the chemiluminescent determination of NO/NO.sub.x in a sample gas is disclosed in which the NO.sub.x portion of the gas stream is catalytically converted in a preconditioned vitreous carbon bed at a relatively low temperature effective to catalytically convert NO.sub.x to NO and below 200.degree. C. The vitreous carbon is preconditioned by heating at a temperature of between 300.degree. C. and about 500.degree. C. for a sufficient period of time, on the order of two to five hours. The apparatus consists of a converter containing the preconditioned vitreous carbon in communication with a reaction cell consisting of a hollow cylindrical housing having an open end closed by an optical filter. A suitable photodetecter is disposed to detect light emitted through the optical filter. A chemiluminescent reaction between ozone and NO in the sample stream occurs in a reaction chamber defined by the interior of the housing. A reflector element may be disposed in the reaction chamber.

Abstract: This invention relates to a method for catalyzing the reactionsQZ+H.sub.2 X?QZX (1)andQZX?QZ+H.sub.2 X (2)whereinQ=C or N;Z=O or S;X=O, S, NH or NR;R=C.sub.1 to C.sub.8 alkyl which may be linear, branched or cyclized,which comprises:contacting at least one polydentate nitrogen-containing chelating agent complexed with a metal atom with the reactants of one of said reactions, wherein said contacting takes place in the presence of a means for oxidizing when reaction (1) is catalyzed and in the presence of a means for reducing when reaction (2) is catalyzed. A particular reaction is the conversion of NO to NO.sub.2 using water and supported porphines, hemes, phthalocyanines, ethioporphrins sirohemes, particularly heme and heme compounds or derivatives such as methemoglobin, myoglobin, or hemin.

Abstract: A process for recovering elemental chlorine from ferrous chloride produced during chlorination of a titaniferous ore or ore beneficiate by oxidizing ferrous chloride in a fluidized bed of particulate material which is inert, e.g., sand, continuously oxidizing first to ferric chloride and then to ferric oxide as one stage.

Abstract: The fixation of nitrogen by electric arc process is made more efficient by this system which combines a low frequency electric discharge and a catalyst in such a way that an electric arc is formed entirely within a catalyst bed when the reactant gases to be reacted by the arc are admitted to the interior of the catalyst bed and form a cavity there as they expand outward, the bubble-like cavity formed within the mass of catalytic particles thereby providing a type of arc chamber from which plasma state gas particles immediately contact the catalyst particles as the plasma state, gas particles are thrust outwards from the arc zone. After the reactant gases react on catalyst particles, the outward pressure moves the product gases farther through the catalyst bed where the products are then shielded from destructive ultraviolet light from the arc.

Abstract: Mixtures of reactant gases containing nitrogen ar reacted by being raised to very high temperatures at the focal plane of a solar concentrator when radiant energy is absorbed by a metal screen or other porous material in contact with the reactants at the focal plane of a solar concentrator and the resulting products of combined nitrogen are rapidly cooled in a unique heat transfer unit which rapidly transfers the heat of the product gases to the reactant gases and the rapid cooling of the product fixes the high temperature equilibrium proportions to achieve larger proportions of product than would be possible by gradual cooling.

Abstract: A process for the removal of NO.sub.x impurities from a gas stream which comprises treating the gas stream containing NO.sub.x impurities under cryogenic conditions with oxygen and an unsaturated hydrocarbon, removing solid N.sub.2 O.sub.3 and recovering a gas stream reduced in NO.sub.x.

Abstract: This invention relates to a method for catalyzing the reactionsQZ+H.sub.2 X.fwdarw.QZX (1) psandQZX.fwdarw.QZ+H.sub.2 X (2)wherein Q=C or N;Z=O or S;X=O, S, NH or NR;R=C.sub.1 to C.sub.8 alkyl which may be linear, branched or cyclized,which comprises:contacting at least one polydentate nitrogen-containing chelating agent complexed with a metal atom with the reactants of one of said reactions, wherein said contacting takes place in the presence of a means for oxidizing when reaction (1) is catalyzed and in the presence of a means for reducing when reaction (2) is catalyzed.

Abstract: Hydrogen sulfide and hydrogen cyanide are catalytically removed from air at room temperatures. Air containing H.sub.2 S and HCN in dilute concentrations is contacted with a dry, activated catalyst formed of palladium (II) and copper (II) salts such as chlorides, on an alumina substrate, at a temperature in the range of -20.degree. C. to 85.degree. C. The catalyst may also contain nickel (II) chloride.

Abstract: A system and a method of nitrogen fixation is disclosed in which nitrogen and other gases such as oxygen are electrically activated and reacted on a catalyst-like material to provide a fixed nitrogen product in such a way that the reactant gases are first placed into an excited state by a single electrode electric discharge acting on a gas stream and then by means of the stream the reactants are contacted on the catalyst-like material on which they are then combined and the product compounds which are thereby formed are shielded by the same catalytic material from ultra violet radiation generated by the electric excitation, said shielding being to prevent subsequent disassociation of the product compounds, and the gas stream emerging on the downstream side of the catalyst carries the products to an absorption bed on which they are absorbed and concentrated and then reacted with a periodic flow of hydrogen to provide ammonia.

Abstract: A process for the fixation of nitrogen is disclosed which comprises combining a mixture of nitrogen, oxygen, metal oxide and water vapor, initially heating the combination to initiate a reaction which forms nitrate, but at a temperature and pressure range below the dissociation pressure of the nitrate. With or without the water component, the yield of fixed nitrogen is increased by the use of a Linde Molecular Sieve Catalyst.

Abstract: The concentrations of NO and NO.sub.2 in nitrogen oxides contained in an exhaust gas are adjusted to substantially equal mol concentrations, whereupon the exhaust gas is held in contact with a metallic oxide catalyst together with ammonia. Owing to the adjustment of the NO and NO.sub.2 concentrations in the nitrogen oxides, the reaction rate is enhanced, and the nitrogen oxides are reduced even at a low temperature. The adjustment of the concentrations of NO and NO.sub.2 in the nitrogen oxides is done by the oxidation of NO with ozone, the catalytic oxidation of NO with air or oxygen, the addition of nitric acid, the addition of NO or NO.sub.2, etc.

Abstract: Nitrous oxide can be produced by reacting nitric oxide and carbon monoxide in the presence of a catalyst in an anhydrous system. The preferred catalyst is a mixture of PdCl.sub.2, CuCl.sub.2 and LiCl, which is dissolved in anhydrous methanol.

Abstract: A process for the fixation of nitrogen comprising, combining a gaseous nitrogen and oxygen at a total pressure of above 100 atmospheres with a solid oxide which can produce a nitrate, in the presence of an oxide of silicon catalyst for the acceleration of a reaction between nitrogen and oxygen to produce nitrogen oxides, initially heating the combination to a temperature of between 600.degree. C. to 800.degree. C. and below the dissociation pressure of the nitrate to start an exothermic reaction for producing nitrogen oxides from the nitrogen and oxygen and for producing nitrate from the solid oxide and to establish an equilibrium between the nitrogen, oxygen, nitrogen oxides, solid oxide and nitrate. The reacting combination in equilibrium is then cooled and either the nitrate or the nitrogen oxides are removed from the reaction as products.

Abstract: A process for the fixation of nitrogen comprising, combining a gaseous nitrogen and oxygen at a total temperature of about 100 atmospheres with a solid oxide which can produce a nitrate, in the presence of a catalyst for the acceleration of a reaction between nitrogen and oxygen to produce nitrogen oxides, initially heating the combination of a temperature of between 600.degree. C. to 800.degree. C. and below the dissociation pressure of the nitrate to start an exothermic reaction for producing nitrogen oxides from the nitrogen and oxygen and for producing nitrate from the solid oxide and to establish an equilibrium between the nitrogen, oxygen, nitrogen oxides, solid oxide and nitrate. The reacting combination in equilibrium is then cooled and either the nitrate or the nitrogen oxides are removed from the reaction as products.

Abstract: The present invention relates to a process for the preparation of nitrogen oxides (NO and NO.sub.2) by the reaction of nitrogen and oxygen in a plasma furnace.According to this process, a plasma of oxygen and nitrogen is introduced into the reaction chamber of the plasma furnace, whereof the internal surface of the walls is covered with a catalyst chosen from tungsten trioxide (WO.sub.3) and molybdenum trioxide (MoO.sub.3).

Abstract: A process for the oxidation of nitric oxide to nitrogen dioxide in the presence of elemental nitrogen with minimal oxidation thereof which comprises combining the nitric oxide with a predetermined amount of oxygen containing gas to give at least 1% stoichiometric excess of oxygen for the oxidation of nitric oxide to nitrogen dioxide and passing the resulting mixture over a ceramic catalyst of the following empirical formula at a temperature between about 100.degree. C. and about 400.degree. C.;W.sub.k X.sub.n J(l-k-n).sup.ZO (3.+-.m) wherein W is Zirconium, Tin or Thorium or mixtures thereof; X is an alkaline earth metal or mixture thereof; J is scandium, yttrium; a rare-earth element or mixture thereof; Z is a metal of the first transition series or a mixture thereof, at least 0.01% of said metal having an oxidation state other than +3; k is a number having a value between 0 and about 0.1; m is a number having a value of from 0 to about 0.26; and n is a number having a value from 0 to about 0.

Abstract: Nitrous oxide (laughing gas) is produced by continuous decomposition of ammonium and nitrate ions fed into an aqueous, strongly acid reaction liquor containing chloride ion as catalyst. N.sub.2 O and water are continuously removed.Preferred parameters areHydrogen ion 3 - 7 M, preferably, 4 - 6M, say 5-5.7M; chloride ion 0.05 - 0.45 M, preferably 0.05-0.3M, say 0.1-0.2M; nitrate ion 4-16M, preferably 8.5 - 15M, say 12-14.5M; ammonium ion 1M or more, preferably 4.5 - 9M, say 7 - 9M. temperature: above 80.degree. C, preferably 105.degree.-120.degree. C.The temperature is so maintained that the reaction liquor boils at the reaction temperature, the excess water being continuously removed by fractional distillation. The N.sub.2 O which is withdrawn overhead, is scrubbed with caustic alkali to remove chlorine contamination in the form of hypochlorite byproduct.The process offers a high degree of safety, flexibility and ease of control and can be carried out with inexpensive technical grades of ammonium nitrate.

Abstract: The present invention provides a novel process for treating a fluid stream carrying various components including nitrogen oxides, wherein the stream is subjected to oxidative reactions under gaseous and absorptive conditions to convert a portion of the nitrogen oxides to nitric acid and thereby simultaneously reduce the concentration of nitrogen oxides in the stream discharge.

Abstract: Process for removing nitrogen oxides from a gaseous mixture comprises contacting the mixture with an aqueous liquid in the presence of a knitted wire mesh packing material of stainless steel containing at least 8% Ni and having a diameter of from 0.003 to 0.015 inches.