The invention relates to a catalyst comprising a mixture of AFX-structure and BEA-structure zeolites and at least one additional transition metal, to the process for preparing same and to the use thereof for the selective catalytic reduction of NOx in the presence of a reducing agent such as NH.sub.3 or H.sub.2.

The present invention discloses a method for ammonium-enhanced flue gas desulfurization (FGD) by using red mud slurry. The method specifically includes: crushing red mud, sieving the crushed red mud, slurrying the red mud, conducting aeration treatment, adding an ammonium salt and/or ammonia, and conducting natural sedimentation to obtain pretreated red mud slurry and pretreated red mud liquor; adding an ammonium salt and/or ammonia to the slurry, adding water and conducting uniform mixing, conducting pre-FGD, conducting deep desulfurization on treated flue gas by using the pretreated red mud liquor, and directly discharging desulfurized flue gas; and charging the pretreated red mud slurry and the pretreated red mud liquor obtained after the treatment to a replacement tank below, adding lime milk to the replacement tank, conducting stirring and natural sedimentation, conducting soilization on subnatant thick red mud slurry, and refluxing the supernatant to a red mud aeration tank.

Disclosed is a method for diagnosing a first exhaust treatment component for treatment of an exhaust gas stream comprising means for oxidizing nitric oxide into nitrogen dioxide. A first reduction catalytic converter is arranged upstream said means for oxidizing nitric oxide into nitrogen dioxide, and a second reduction catalytic converter is arranged downstream said means. A reagent is for reduction of nitrogen oxides in said first catalytic converter, and a first sensor measures an occurrence of nitrogen oxide downstream said means but upstream said second reduction catalytic converter. The method comprises: causing a supply of reagent upstream said first reduction catalytic converter to an extent exceeding the extent to which reagent is consumed by the first reduction catalytic converter, determining a first measure of the occurrence of reagent downstream said means for oxidizing, and diagnosing said means for oxidizing nitric oxide into nitrogen dioxide based on said first measure.

Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

A denitration device comprising a duct (22) that leads and distributes exhaust gas from a turbine (56) of a gas turbine (50) including a compressor (52) and the turbine (56), an ammonia injection grid (24) that sprays, into the duct (22), an mixed gas in which ammonia gas and dilution air are mixed with each other, and a denitration catalyst (26) that is installed on a downstream side of flow of the exhaust gas of the ammonia injection grid in the duct (22), and there is provided an air bleeding line (76) that is connected to a low compression portion of the compressor (52) of the gas turbine (50) and supplies air bled of the compressor (52) into the ammonia injection grid (24) as the dilution air.

The present invention relates to a process for the preparation of a zeolitic material SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein X stands for a trivalent element, wherein said process comprises interzeolitic conversion of a first zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein the first zeolitic material has an FER-, TON-, MTT-, BEA-, MEL-, MWW-, MFS-, and/or MFI-type framework structure to a second zeolitic material comprising SiO.sub.2 and X.sub.2O.sub.3 in its framework structure, wherein the second zeolitic material obtained in (2) has a different type of framework structure than the first zeolitic material. Furthermore, the present invention relates to a zeolitic material per se as obtainable and/or obtained according to the inventive process and to its use, in particular as a molecular sieve, as an adsorbent, for ion-exchange, or as a catalyst and/or as a catalyst support.

Apparatus and methods for treating acid gas, which utilizes multi-stage absorption cycle of ammonia desulfurization to treat acid tail gas after pre-treatment of the acid gas, thereby achieving the purpose of efficient and low-cost treatment of acid tail gas. The parameters of the acid tail gas may be adjusted by a regulatory system such that the enthalpy value of the acid tail gas is in the range of 60-850 kJ/kg dry gas, for example, 80-680 kJ/kg dry gas or 100-450 kJ/kg dry gas, to meet the requirements of ammonia desulfurization, and achieve the synergy between the acid gas pre-treatment and ammonia desulfurization. Furthermore, hydrogen sulfide may be converted into sulfur/sulfuric acid plus ammonium sulfate at an adjustable ratio.

A material (such as potassium hydroxide or ammonia) capable of reacting with ambient carbon dioxide to produce fertilizer is placed in the path of ambient air movement. Desirably the material is associated with a fabric which in turn is associated with a vane of a vertical axis wind turbine, the turbine performing useful work as well as supporting the material which produces a fertilizer. A misting system controlled by a controller may automatically apply a water mist to the material if the humidity is below a predetermined level. The fabric with produced nitrogen and/or potassium fertilizer may be placed directly into contact with soil, or shredded first, or burned to produce energy and an ash (and the ash applied to the soil). The wind turbine may have a convenient, versatile mounting system with three adjustable legs supporting a central component, and the spokes of the wind turbine may be slotted for easy assembly with vanes.

A catalyst composition for selective catalytic reduction of NO.sub.x by ammonia or compounds, such as urea, generating ammonia under exhaust gas conditions. The composition includes a) a copper ion exchanged zeolite particles having a Si/Al.sub.2 molar ratio (SAR) of 15 or less and a copper content sufficiently high to perform the catalytic reduction, b) a nanocrystalline aluminium compound in an amount sufficient for stabilizing the zeolite, and c) a zirconium compound in an amount sufficient to improve hydrothermal durability of the catalyst composition.

The present invention relates to the technical field of flue gas denitration catalysts, and discloses a hydrogenated TiO.sub.2 denitration catalyst and a preparation method and use thereof. The hydrogenated TiO.sub.2 denitration catalyst has a crystal form of anatase form, with oxygen vacancies and surface hydroxyl groups; wherein the hydrogenated TiO.sub.2 denitration catalyst contains TiO.sub.2, SO.sub.3 and P.sub.2O.sub.5, and based on the total weight of the hydrogenated TiO.sub.2 denitration catalyst, the content of TiO.sub.2 is 98-99.8% by weight, the content of SO.sub.3 is 0.2-1% by weight, and the content of P.sub.2O.sub.5 is 0.1-0.2% by weight. The hydrogenated TiO.sub.2 denitration catalyst has high denitration activity at 300-400° C. and N.sub.2 selectivity as high as 85% or more, and can be used in NH.sub.3—SCR denitration.