摘要:
A gas stream containing nitrous oxide and ammonia is contacted with a catalyst composition containing a zeolite. N2O is reduced to N2 and H2O at low temperatures in a highly efficient manner. Ammonia-mediated reduction of nitrous oxide can be effectuated from gas streams having N2O concentrations as low as 1%. The gas stream may also contact a catalytic composition selective for the reduction of NOx. In this way, N2O and NOx treatment may be effectuated in a single process stream.
摘要:
A structure and system for the adsorption of carbon dioxide from air, the system comprising a sorbent structure comprising a porous substrate having a porous alumina coating on the surfaces of said substrate, and the sorbent for carbon dioxide is embedded on the surfaces of said porous alumina coating. The substrate is preferably a porous monolith, formed from silica or mesocellular foam. The sorbent is an amine group-containing material, preferably loaded at 40 to 60 percent by volume relative to the porous alumina coating.
摘要:
Sorbents for removal of mercury and other pollutants from gas streams, such as a flue gas stream from coal-fired utility plants, and methods for their manufacture and use are disclosed. The methods include mixing fly ash particles with a sulfide salt and a metal salt to form a metal sulfide on the outer surface of the fly ash particles.
摘要:
The invention pertains to a layered ammonia oxidation catalyst. The layered catalyst causes ammonia to be selectively oxidized in the presence of an oxidant such as air, while minimizing the formation of nitrogen oxides (NOx). The layered catalyst comprises a refractory oxide support such as gamma alumina upon which a platinum component is deposited and a vanadia component is deposited on the platinum. The catalyst is preferably disposed on a substrate such as a metal foil whose surface contains a “herringbone” pattern.
摘要:
The present invention is directed to an iron-promoted zeolite beta catalyst useful in the selective catalytic reduction of nitrogen oxides with ammonia in which the iron-promoted zeolite beta is treated so as to provide increased amounts of the iron promoter in the form of Fe(OH). The stabilized zeolite is formed by cation exchange of an iron salt into a zeolite beta which has a reduced sodium content such as by exchanging a sodium beta with ammonium or hydrogen cations. A zeolite beta having a reduced carbon content and a Si/Al ratio of no more than 10 also increases the Fe(OH) content of the iron-promoted catalyst. The iron-promoted catalyst which has the iron in the form of Fe(OH) is characterized by a peak at 3680±5 cm−1 in the IR spectra.
摘要:
Sorbents for removal of mercury and other pollutants from gas streams, such as a flue gas stream from coal-fired utility plants, and methods for their manufacture and use are disclosed. The methods include mixing sorbent substrate particles with a sulfide salt and a metal salt to form a metal sulfide on the outer surface of the sorbent particles.
摘要:
Catalysts, catalyst systems, and methods for removing ammonia and/or carbon monoxide in flue gases are provided where ammonia is used with a selective catalytic reduction catalyst for reducing oxides of nitrogen. An oxidation catalyst is utilized, which comprises particulate platinum or platinum/palladium dispersed on zirconia particles, the particulate platinum or platinum/palladium having an average particle size less than about 10 nm. The catalyst is effective to convert less than 20% of NO to NO2 passing through the oxidation catalyst.
摘要:
A catalyst for the oxidation of volatile organic compounds and carbon monoxide comprising manganese and alumina, such catalyst having been impregnated with a phosphorus compound. The presence of the phosphorus compound results in a significant oxidative conversion of both the volatile organic compounds and the carbon monoxide. The catalyst is especially useful for treating gaseous streams that emanate from industrial sources, such as wood pulp manufacturing plants. The manganese portion of the catalyst is preferably comprised of manganese compounds comprising a defect non-stoichiometric manganese oxide of the type β-Mn3O4+x, wherein x has the value of 0.1≦x≦0.25 in respect to about 80 to about 95% of all manganese atoms, and manganese aluminate in respect to the balance of the manganese atoms. The alumina portion of the catalyst is preferably comprised of high temperature forms of alumina of the type comprising α-Al2O3 and (α+δ+θ)-Al2O3.
摘要翻译:用于氧化包含锰和氧化铝的挥发性有机化合物和一氧化碳的催化剂,这种催化剂已经用磷化合物浸渍。 磷化合物的存在导致挥发性有机化合物和一氧化碳的显着氧化转化。 催化剂特别适用于处理从工业来源产生的气流,如木浆制造厂。 催化剂的锰部分优选包含锰化合物,其包含类型为β-Mn 3 O 4 + x N的缺陷非化学计量的氧化锰,其中x具有 相对于锰原子的平衡,相对于约80至约95%的所有锰原子,0.1 <= x <= 0.25的值和铝酸锰。 催化剂的氧化铝部分优选由包含α-Al 2 O 3 3和(α+δ+θ)3 Al 3+的类型的高温形式的氧化铝组成, SUB> 2 O> 3。
摘要:
Methods of manufacturing bentonite sorbents for removal of pollutants including mercury from gas streams, such as a flue gas stream from coal-fired utility plants are disclosed. The methods include mixing bentonite sorbent particles with a sulfide salt and a metal salt to form a metal sulfide on the outer surface of the bentonite sorbent particles.