Disclosed is a dual pressure plant for the production of nitric acid on the basis of the oxidation of ammonia. The plant comprises a reactor configured to produce a burner gas stream; a gas cooling section configured to form a cooled burner gas; a condensation section configured to form an aqueous nitric acid condensate and an uncondensed nitrogen oxides gas stream; an absorption section configured to produce raw nitric acid and a tail gas; and a tail gas treatment system configured to form a purified tail gas. In a tail gas heating section a further heat exchanger configured to receive heat from the burner gas stream, said further heat exchanger being positioned relatively close to the reactor.

A process for removing hydrocarbons from a feed stream containing hydrocarbons includes introducing ozone to the feed stream to produce an ozone doped stream containing ozone and hydrocarbons, and contacting the ozone doped stream with a supported metal catalyst at a temperature of from 100° C. to 300° C. to produce a treated stream, wherein the supported metal catalyst comprises iron supported on a support selected from aluminosilicates, silica-aluminas, silicates and aluminas. A process for removing NOx from a feed stream containing NOx, and an apparatus for removing hydrocarbons and/or NOx from a feed stream containing hydrocarbons and/or NOx are also provided.

The disclosure discloses an anti-haze anti-harmful gas air filter membrane as well as a preparation method and application thereof. The air filter membrane comprises a nano fiber membrane made of nano fibers and having a two-dimensional or three-dimensional network structure. The nano fiber membrane can be a high-molecular polymer nano fiber membrane prepared by utilizing an electrostatic spinning process, and can also be doped with an organic or inorganic additive capable of adsorbing and absorbing harmful gases, such as VOCs, NO.sub.x, SO.sub.x and NH.sub.3, in the air and/or a photocatalyst capable of degrading these harmful gases in a photocatalysis manner, or the like. The anti-haze anti-harmful gas air filter membrane disclosed by the disclosure can efficiently filter PM2.5 and PM10 particulate pollutants and the like in the air and simultaneously can efficiently identify and clear multiple harmful gases in the air. The anti-haze anti-harmful gas air filter membrane has a wide application prospect in the field of air purification, for example, can be applied to air purification devices, such as screen windows, gauze masks and filter screens.

Some embodiments of the present disclosure relate to a method of regenerating at least one filter medium comprising: providing at least one filter medium, wherein the at least one filter medium comprises: at least one catalyst material; and ammonium bisulfate (ABS) deposits, ammonium sulfate (AS) deposits, or any combination thereof; flowing a flue gas stream transverse to a cross-section of a filter medium, such that the flue gas stream passes through the cross section of the at least one filter medium, wherein the flue gas stream comprises: NOx compounds comprising: Nitric Oxide (NO), and Nitrogen Dioxide (NO.sub.2); and increasing an NOx removal efficiency of the at least one filter medium after removal of deposits.

The present disclosure is directed to the use of elemental or speciated iodine and bromine to control total mercury emissions.

Process for reducing the content of NOx and N2O from an input tail gas (10) of a nitric acid process, said input tail gas having a temperature lower than 400 C., the process comprising an abatement stage at least including a deN2O stage and deNOx stage and providing a conditioned tail gas (12) having a temperature greater than the input tail gas (10), wherein, prior to submission to said abatement stage, said input tail gas (10) is pre-heated to a temperature of at least 400 C. by indirect heat exchange with at least a portion of said conditioned gas (12).

A catalyst bed comprising a ceramic or metallic foam comprising one or more NOx reduction catalysts is described. Further, a method for reducing the concentration of NOx in a dust containing gas stream comprising: a) passing a first gas stream containing NOx into a contacting zone; b) contacting the first gas stream with a ceramic or metallic foam catalyst bed having one or more flow paths through the catalyst bed wherein the ceramic or metallic foam comprises a NOx reduction catalyst to produce a second gas stream with a reduced NOx concentration; and c) passing the second gas stream out of the contacting zone wherein the first gas stream has a dust concentration of at least 5 mg/Nm3 and the second gas stream comprises at least 50% of the amount of dust in the first gas stream.

An oxygen storage material (OSM) that exhibits enhanced redox properties, developed mesoporosity, and a resistance to sintering. The oxygen storage material (OSM) has a high oxygen storage capacity (i.e., OSC>1.5 mmol H.sub.2/g) and enhanced reducibility (i.e., bimodal TPR-H.sub.2 profile with two T.sub.max in the temperature range from 150 C. to 550 C.). The OSM is suitable for use as a catalyst and a catalyst support. The method of making the oxygen storage material comprises the preparation of a solution containing zirconium, cerium, rare earth and transition metal salts, followed by the co-precipitation of all constituent metal hydroxides with a base.

An all-condition auxiliary denitration system and an operation method thereof are provided. The system includes a heat-storage medium heater, a low-temperature reheater, an economizer, and an SCR denitration device which are successively interconnected, and further including a heat-storage medium tank and a heat-storage medium and feedwater heat exchanger. A flow of a cold heat-storage medium entering the heat-storage medium heater is regulated, so that heat absorption of the heat-storage medium is matched with a boiler load. Flows of hot heat-storage medium and feedwater, which enter the heat-storage medium and feedwater heat exchanger, are regulated through a feedwater regulating valve and a hot heat-storage medium outlet regulating valve. A total feedwater flow is regulated with assistance of a bypass feedwater regulating valve, so that a temperature of flue gas entering the SCR denitration device is kept in an optimal operation range under different boiler loads, and denitration efficiency is ensured.

Some embodiments of the present disclosure relate to a method of regenerating at least one filter medium comprising: providing at least one filter medium, wherein the at least one filter medium comprises: at least one catalyst material; and ammonium bisulfate (ABS) deposits, ammonium sulfate (AS) deposits, or any combination thereof; flowing a flue gas stream transverse to a cross-section of a filter medium, such that the flue gas stream passes through the cross section of the at least one filter medium, wherein the flue gas stream comprises: NO.sub.x compounds comprising: Nitric Oxide (NO), and Nitrogen Dioxide (NO.sub.2); and increasing an NO.sub.x removal efficiency of the at least one filter medium after removal of deposits.