This disclosure provides an apparatus and method for reducing emissions of nitrogen oxides (NO.sub.x) from a combustion source. For example, a method and apparatus for injecting a urea solution directly into the flue gas stream of a coal-fired power plant that utilizes Selective Catalytic Reduction (SCR) to lower NO.sub.x emissions.

Disclosed in the present invention is a tail gas treatment catalyst. The catalyst consists of a carrier, a first catalyst, and a second catalyst. The first catalyst and the second catalyst are provided on both ends of the carrier. The first catalyst can purify pollutants in tail gas. The second catalyst can purify a byproduct, ammonia, obtained by the purification by the first catalyst and pollutants that are not completely purified by the first catalyst. The second catalyst is of a double-layer structure; the lower layer consists of an oxygen storage material, aluminum oxide, and a second active component; the second active component is a composition of Pt and Pd, or a composition of Ce, Fe, Ni and Cu; the upper layer consists of a molecular sieve and a third active component; the third active component is Cu or a composition of Cu and Fe. The tail gas treatment catalyst of the present invention has high purification treatment efficiency, and can significantly reduce the emissions of CH.sub.4, CO, and NO.sub.x in the tail gas, especially reduce the content of the byproduct, NH.sub.3, so that the tail gas can meet China VI emission standards.

A catalyst for treating an exhaust gas comprising SO.sub.2, NO.sub.x and elemental mercury in the presence of a nitrogenous reductant comprises a composition containing oxides of: (i) Molybdenum (Mo) and optionally Tungsten (W); and (ii) Vanadium (V); and (iii) Titanium (Ti); and (iv) Phosphorus (P), wherein, with respect to the total metal atoms in the composition, the composition comprises: (i) Mo in an amount of less than 2 at. %, and optionally up to 9 at. % W; (ii) from 2.5 to 12 at. % V; (iii) from 85 to 96 at. % Ti, and wherein the composition comprises (iv) P in an atomic ratio to the sum of atoms of Mo, W and V of from 1:2 to 3:2. The values expressed must total 100%.

A method for preparing a ceramic composition while simultaneously reducing the quantity of carbon dioxide from municipal solid waste that would discharge into environment includes decomposing the municipal solid waste to generate a carbon dioxide-water vapor mixture, providing a matrix, the matrix containing a reactant; and contacting the carbon dioxide-water vapor mixture with the matrix to promote a reaction between the carbon dioxide of the carbon dioxide-water vapor mixture and the reactant of the matrix. The reaction forms a product, thereby producing the ceramic composition.

Centralizing the handling and manipulating of vaporization medium to a single subsystem that supplies multiple ammonia vaporizers allows for efficient and effective production of a corresponding vaporized ammonia stream containing a controlled quantity of ammonia. These vaporized ammonia streams can then be used in conjunction with ammonia-consuming devices to reduce NOx in NOx-containing exhaust streams from multiple furnaces.

The invention pertains to processes for separating gases, acid gas, hydrocarbons, air gases, or combinations thereof. The processes may employ using a liquid phase cloud point with or without subsequent liquid-liquid separation. In some embodiments membranes can be employed with reverse osmosis to regenerate a solvent and/or an antisolvent. In some embodiments thermal switching phase changes may be employed during absorption or desorption to facilitate separation.

A carbon dioxide separation and capture apparatus includes an absorption tower configured to cause an absorbing liquid to absorb a carbon dioxide gas contained in a process gas and a regeneration tower configured to cause the absorbing liquid from the absorption tower to release the carbon dioxide gas. The carbon dioxide separation and capture apparatus further includes an inlet concentration meter configured to measure concentration of an acid component in the process gas supplied to the absorption tower and an outlet concentration meter configured to measure concentration of the acid component in the process gas discharged from the absorption tower. Also included in the carbon dioxide separation and capture apparatus are a supplementary absorbing liquid supply mechanism configured to supply a supplementary absorbing liquid to the main unit and a controller configured to control an amount of the supplementary absorbing liquid supplied to the main unit by the supplementary absorbing liquid supply mechanism based on the concentrations of the acid component measured at the inlet concentration meter and the outlet concentration meter.

A liquid film dust arrester is installed to face a gas flow containing dust and flowing out from a gas discharge pipe. The arrester includes a gas flow blocking unit arranged vis--vis the gas flow, a liquid dispersion unit having a dispersion section arranged at a position near the center of the gas flow blocking unit and upstream relative to the gas flow blocking unit as viewed in the flowing direction of the gas flow so as to face the gas flow blocking unit, a liquid ejection unit having an ejection port disposed vis--vis the dispersion section and configured to eject liquid from the ejection port, and a liquid film forming unit. The dispersion section comprises a smooth surface that causes the ejected liquid to flow and disperse on the smooth surface, and the liquid film is formed to face the gas flow flowing through the flow path.

Polymeric sorbents for aldehydes including formaldehyde are provided. More particularly, the polymeric sorbents are a reaction product of a divinylbenzene/maleic anhydride precursor polymeric material with a nitrogen-containing compound. The nitrogen-containing compound is covalently attached to the resulting polymeric sorbent. Additionally, methods of sorbing aldehydes (i.e., aldehydes that are volatile under use conditions) on the polymeric sorbents and compositions resulting from the sorption of aldehydes on the polymeric sorbents are provided. The polymeric sorbents typically are porous with the pores often being in the size range of mesopores and/or micropores.

A catalyst for treating an exhaust gas comprising SO.sub.2, NO.sub.x and elemental mercury in the presence of a nitrogenous reductant comprises a composition containing oxides of: (i) Molybdenum (Mo) and/or Tungsten (W); (ii) Vanadium (V); (iii) Titanium (Ti), and (iv) an MFI zeolite, wherein the composition comprises, based on the total weight of the composition: (i) 1 to 6 wt % of MoO.sub.3 and/or 1 to 10 wt % WO.sub.3; and (ii) 0.1 to 3 wt % V.sub.2O.sub.5, and (iii) 48.5 to 94.5 wt % TiO.sub.2; and (iv) 35 to 50 wt % MFI zeolite.