摘要:
A method is provided for reducing NO.sub.x for high flow applications such as NO.sub.x abatement in an exhaust gas from an internal combustion engine operating under lean burn conditions wherein NO.sub.x is reduced by hydrocarbon reductants. The method employs a hydrothermally stable catalyst comprising transition metal-containing ZSM-5 which is prepared by in-situ crystallization of an aggregate comprising ZSM-5 seeds, silica, and a crystalline silicate.
摘要:
A new zeolite, designated ZSM-22, is disclosed and claimed. The new zeolite has the composition, in the anhydrous state, expressed in terms of mole ratios of oxides as follows:(x)Q.sub.2 O:(y)M.sub.2/n O:(z)L.sub.2 O.sub.3 :100SiO.sub.2wherein Q.sub.2 O is the oxide form of an organic compound containing an element of Group 5-B (as defined in the Table of the Elements--National Bureau of Standards, Fischer Scientific Co. Catalog No. 5-702-10), e.g., N or P, preferably N, containing at least one alkyl or aryl group having at least 2 carbon atoms, M is an alkali or alkaline earth metal having a valence n, e.g., Na, K, Cs or Li and wherein x=0.01-2.0, y=0-2.0, z=0-5, and L=Al. The zeolite is useful in the process of catalytic conversion of alcohols and/or oxygenates to gasoline-grade hydrocarbons.
摘要:
A process for catalytically cracking a hydrocarbon feed in a reaction zone under catalytic cracking conditions in the absence of added hydrogen with a catalyst comprising a conventional cracking catalyst. The improvement comprises adding to the conventional cracking catalyst a thermally treated zeolite having a mole ratio of SiO.sub.2 :Al.sub.2 O.sub.3 of about 10:1 to 100:1 and a constraint index of about 1 to 12. Thermal treatment reduces the additive zeolite's alpha activity to about 1 to 10 prior to use.
摘要翻译:在催化裂化条件下,在没有加入氢气的情况下,用含有常规裂化催化剂的催化剂,在反应区中催化裂化烃原料的方法。 改进包括向常规裂化催化剂中加入具有约10:1至100:1摩尔比的SiO 2 :Al 2 O 3的热处理沸石,约1至12的约束指数。热处理将添加沸石的α活性降低至约 使用前1至10。
摘要:
The invention provides a method of making large crystallite zeolites by a method comprising forming the zeolite in a medium containing a combination of two different alkylammonium cations or a combination of an alkylammonium cation and a metallic cation. In the combination at least one of the cations will have an ionic radius of from about 1.40 to the pore size of the specific zeolite.
摘要:
Propylation of toluene with selective production of cymene is accomplished by vapor phase reaction of toluene and propylene at a temperature between about 400.degree. and about 600.degree. F. in the presence of a catalyst comprising a crystalline aluminosilicate zeolite, said zeolite having a silica to alumina ratio of at least about 12 and a constraint index, as hereinafter defined, within the approximate range of 1 to 12.
摘要:
As synthesized by conventional technique, zeolite ZSM-5 is crystallized in the presence of substantial amount of tetraalkylammonium cations, the alkyl groups of which contain 2 to 5 carbon atoms, such as, for example, tetrapropylammonium. When synthesized in the conventional way, ZSM-5 contains tetraalkylammonium cations as well as a substantial amount of sodium ions. To obtain a more catalytically active form of ZSM-5, the sodium ions must be exchanged to very low levels. By synthesizing zeolite ZSM-5 according to the present method, i.e., in the presence of a combination of an amine and a halide in the presence of a mutual solvent and with a specifically defined reaction mixture composition, ZSM-5 having different organic nitrogen-containing cations but the same crystal structure as conventionally prepared ZSM-5 is obtained. The ZSM-5 prepared in accordance herewith is very low in sodium content as synthesized and has a crystal size of from about 0.05 microns to about 20 microns.
摘要:
A method of removing the organic cation from an organic cation-containing zeolite which comprises contacting the zeolite at low temperatures with an aqueous sodium hypochlorite solution.
摘要:
An improved method is disclosed for converting synthesis gas to hydrocarbon mixtures wherein the syngas is contacted with a special catalyst comprising a crystalline zeolite having a silica-to-alumina ratio of greater than 200 (including zeolites containing essentially no alumina) and an (R.sub.2 O+ M.sub.2 /.sub.n O): SiO.sub.2 ratio of less than 1.1:1 where M is a metal other than a metal of Group IIIA, n is the valence of said metal, and R is an alkyl ammonium radical, said organosilicate being characterized by a specified x-ray diffraction pattern. In a specific embodiment of this invention, synthesis gas is contacted with a catalyst comprising an intimate mixture of said crystalline zeolite catalyst and iron-containing, Fischer-Tropsch catalyst to produce a liquid hydrocarbon product having a boiling range of less than 400.degree. F. at a 90 percent overhead and being a predominantly olefinic product, wherein the structure of the olefins is substantially branched chain with internally-positioned double bonds.
摘要:
The conversion of methanol to gasoline boiling products in a plurality of sequentially arranged catalyst beds comprising a dehydration catalyst followed by a special class of crystalline zeolite conversion catalyst is described wherein the dehydration catalyst life is prolonged and durene formed in the process is recycled to the zeolite catalyst conversion step.