Catalyst compositions and methods of preparation comprising: preparing a promoter metal-molecular sieve catalyst composition comprising a promoter metal and a molecular sieve; and incorporating an iron salt into the promoter metal-molecular sieve catalyst composition.

A process for recovering nitric acid or salts thereof, comprising: contacting, in the presence of water, an water-immiscible ionic liquid of the formula [A.sup.+][X.sup.−], wherein [A.sup.+] represents a phosphonium or ammonium cation and [X.sup.−] represents a counter anion which is NO.sub.3.sup.−, an halide anion displaceable by NO.sub.3.sup.−, or both, with a fluid which contains HNO.sub.3 and at least one more mineral acid, or precursors of said acids, and partition, under mixing, said acids between aqueous and organic phases and form nitrate-loaded ionic liquid of the formula [A.sup.+][NO.sub.3.sup.−].sub.z>0.25 where Z indicates a molar amount of nitrate held in the ionic liquid beyond the positions occupied by the nitrate counter ions; separating the so-formed mixture into an organic phase comprising a nitrate-loaded ionic liquid of the formula [A.sup.+][NO.sub.3.sup.−].sub.z>0.25 and an aqueous phase consisting of a nitrate-depleted aqueous solution that contains the other mineral acid(s); stripping the nitric acid from said nitrate-loaded ionic liquid to create an aqueous nitrate solution and regenerate ionic liquid of the formula [A.sup.+][NO.sub.3.sup.−].sub.z≥0 with reduced nitrate loading, or unloaded [A.sup.+][NO.sub.3.sup.−].sub.z=0 ionic liquid.

A device and method of simultaneously removing flammable gases and nitrous oxide are provided. The device includes a thermal oxidation chamber, a high-temperature resistant dust filter, and a catalyst chamber. The thermal oxidation chamber is configured to receive an exhaust gas from a process tool. The exhaust gas includes flammable gases and nitrous oxide. The thermal oxidation chamber has a first exhaust pipe to emit nitrous oxide and dust generated after the exhaust gas is thermally oxidized. The high-temperature resistant dust filter receives dust and nitrous oxide from the first exhaust pipe, wherein the high-temperature resistant dust filter has a filter fiber net and a second exhaust pipe, and the second exhaust pipe is configured to emit nitrous oxide. The catalyst chamber receives nitrous oxide from the second exhaust pipe, wherein the catalyst chamber has a nitrous oxide decomposition catalyst to decompose nitrous oxide into nitrogen and oxygen.

A process for producing nitric acid comprising: catalytic oxidation of ammonia in the presence of oxygen to form a nitrous gas containing NO, O2, N2O and water vapor; a catalytic abatement of N2O which is performed over a first catalyst; a catalytic conversion of NO into NO2 which is performed over a second catalyst; the so obtained nitrous gas is then subject to absorption in water to produce nitric acid.

In a process for preparing nitric acid, nitrogen oxides are first produced in an ammonia combustion plant and cooled in a condenser to form a nitric acid-containing solution. The nitric acid-containing solution is then supplied to at least one absorption tower in which the nitrogen oxides are brought into contact with water and oxygen, wherein the nitrogen-containing gas mixture reacts with the water and the oxygen at least in part to form an aqueous nitric acid-containing solution which accumulates at the base of the absorption tower and is then compressed and recycled via a conduit back into the absorption tower. In order to minimize the concentration of nitrogen oxides in the offgas from such a plant and to increase the efficiency of the process, the invention proposes injecting ozone into a connection conduit which leads from the condenser to a first absorption tower and conducts the nitric acid-containing solution.

The removal of acid gases (e.g., non-carbon dioxide acid gases) using sorbents that include salts in molten form, and related systems and methods, are generally described.

A gas purification catalyst device comprises: a substrate; and one or more catalyst layers on the substrate. Among the one or more catalyst layers, at least one catalyst layer contains both Cu-CHA-type zeolite particles and iron-supporting metal oxide particles in which iron is supported on metal oxide particles.

The present invention relates to an adsorption process for xenon recovery from a cryogenic liquid or gas stream wherein a bed of adsorbent is contacted with a xenon-containing liquid or gas stream selectively adsorbing the xenon from said stream. The adsorption bed is operated to at least near full breakthrough with xenon to enable a deep rejection of other stream components, prior to regeneration using the temperature swing method. After the stripping step, the xenon adsorbent bed is drained to clear out the liquid residue left in the nonselective void space and the xenon molecules in those void spaces is recycled upstream to the ASU distillation column for increasing xenon recovery. The xenon adsorbent bed is optionally purged with oxygen, followed by purging with gaseous argon at cryogenic temperature (≤160 K) to displace the oxygen co-adsorbed on the AgX adsorbent due to higher selectivity of argon over oxygen on the AgX adsorbent. By the end of this step, the xenon adsorbent bed is filled with argon and xenon. Then the entire adsorbent bed is heated indirectly without utilizing any of the purge gas for direct heating. Operating the adsorption bed to near full breakthrough with xenon and displacing the adsorbed oxygen and other residues with argon, prior to regeneration, along with indirect heating of the bed, enables production of a high purity product ≥40 vol % xenon from the adsorption bed and further enables safely heating without any purge gas and ease for downstream product collection, even in cases where hydrocarbons are co-present in the feed stream.

The present invention relates to a catalyst for the oxidation of NO, for the oxidation of ammonia and for the selective catalytic reduction of NOx, comprising a substrate, a first coating comprising one or more of a vanadium oxide and a zeolitic material comprising one or more of copper and iron; and a second coating comprising a platinum group metal component supported on a non-zeolitic oxidic material, wherein the second coating further comprises a zeolitic material comprising one or more of copper and iron.

The present invention relates to a catalyst for the selective catalytic reduction of nitrogen oxide, the catalyst comprising a first coating comprising a 12-membered ring pore zeolitic material comprising a first metal which is one or more of copper and iron, and a second coating comprising an 8-membered ring pore zeolitic material comprising a second metal which is one or more of copper and iron.