摘要:
Silica-bound extruded zeolites may be converted into binder-free zeolite aggregates by aging the zeolite in an aqueous ionic solution which contains hydroxy ions such that the initial molar ratio of OH.sup.- :SiO.sub.2 is up to 1.2 and which causes the silica binder to be converted substantially to zeolite of the type initially bound. Such extrudates have excellent mechanical strength and show advantageous properties such as adsorption comparable with non-extruded zeolite powder.
摘要:
This invention relates to a new zeolite from the class of mazzite, containing a fraction of non-exchangeable potassium cations, and also to a process for its synthesis. The crystallinity and the adsorption capacity of the protonated form of this zeolite are maintained after a prolonged hydrothermal treatment.
摘要:
Synthetic mazzite having a small particle size is advantageously prepared by making present a transparent liquid phase compound in a starting mixture containing a silica source, an alumina source, an alkali source and a tetramethylammonium source.The transparent liquid phase compound is obtained by mixing an aqueous solutuion of an alkali metal silicate, an aqueous solution of an alkali metal aluminate, an aqueous solution of an alkali metal hydroxide and a tetramethylammonium compound and aging the mixture.
摘要:
The invention concerns a stabilized and dealuminated omega zeolite, its manufacture and use in catalytic cracking.It has in particular a SiO.sub.2 /Al.sub.2 O.sub.3 molar ratio higher than 10, a sodium content lower than 0.3%, "a" and "c" crystalline parameters respectively lower than or equal to 1.814 nm and 0.760 nm, a particular capacity for nitrogen adsorption and a particular lattice of secondary pores.
摘要翻译:本发明涉及一种稳定和脱铝的ω-沸石,其制造和用于催化裂化。 特别是具有高于10,低于0.3%的钠含量,分别低于或等于1.814nm和0.760nm的“a”和“c”结晶参数的SiO 2 / Al 2 O 3摩尔比,具有特定氮吸附能力和 二次孔的特定晶格。
摘要:
The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.
摘要:
A method is provided for zeolite synthesis from a synthesis medium containing in particular a trivalent aluminum source, a tetravalent silicon source, at least an alkaline or alkaline-earth cation in hydroxide form and water in a reactor containing a solid helical moving body in a guiding tube defining an internal space and a space external to the tube. The invention is characterized in that the synthesis medium is circulated in the reactor in a continuous flow passing through the internal space then the space external to the tube and returning to the internal space, only driven by the roation of the solid helical moving body, at a speed of less than 500 rpm, in the tube which is kept fixed, the synthesis medium being kept at a temperature suitable for at least one of the ripening operations or the crystal growth of the synthesized zeolite. The invention also is directed to a device for implementing the method.
摘要:
A zeolite, designated zeolite NU-86, having a molar composition expressed by the formula 100 XO.sub.2 : equal to or less than 10 Y.sub.2 O.sub.3 : equal to less than 20 R.sub.2/n O where R is one or more cations of valency n, X is silicon and/or germanium, Y is one or more of aluminum, iron, gallium, boron, titanium, vanadium, zirconium, molybdenum, arsenic, antimony, chromium and manganese and having an X-ray diffraction pattern including the lines shown in Table 1 is prepared from a reaction mixture comprising XO.sub.2 (preferably silica), Y.sub.2 O.sub.3 (preferably alumina) and a polymethylene alpha, omega-diammonium cation. This zeolite is a useful catalyst for a variety of reactions.
摘要:
A method for increasing ion exchange capacity of a titanosilicate comprises contacting the titanosilicate with aqueous alkaline solution having a pH ranging from 7 to 10. The resulting material is especially useful as a support for highly dispersed noble metal.
摘要:
Crystalline aluminosilicate molecular sieves are prepared by (1) forming an aqueous mixture of an oxide of aluminum, an oxide of silicon, a metal or ammonium cation and a suitable oxygen-containing monomeric organic template compound, (2) maintaining the pH of such mixture between 9 and 14, and (3) crystallizing the mixture. The organic templates include ethanolamine, diethanolamine, triethanolamine, ethylethanolamine, ethyldiethanolamine, 2-amino-2-ethyl-1,3-propanediol, morpholine, and alkali metal complexed tetrahydrofuran, dioxane, dioxolane, and crown ethers. Crystalline aluminosilicates prepared include mordenite, ferrierite, ZSM-4, and ZSM-5.
摘要:
An improved method for preparing a crystalline aluminosilicate zeolite having uniform pores and greater than 40 percent crystallinity which comprises forming a critical reaction mixture containing a source of at least two cations, silica, alumina and water, wherein at least about 70 weight percent of the alumina is provided to the reaction mixture by an alumina-containing clay being added thereto, and maintaining the reaction mixture at a temperature and pressure for a time necessary to crystallize the crystalline aluminosilicate from the reaction mixture. It is desirable to preform said reaction mixture into discrete particles such as pellets or extrudates which retain their shape and acquire substantial strength in the crystallization process.