The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A cracking catalyst composition for petroleum feedstocks b. >343°C, with increased selectivity to C 3-4 -alkenes and a C 5+ -gasoline fraction, consists of zeolite β and a shape-selective zeolite with a constraint index of 3-12, at a (wt% shape-selective zeolite)/(wt% shape-selective zeolite + zeolite β) ratio of 0.01-0.95 (matrix-free basis). Suitable shape-selective...
A particulate detergent composition (especially with bulk density 700 g/l) containing an organic surfactant system, a zeolite P builder having a SiAl ratio 1.33 (zeolite MAP), and a bleach catalyst containing Mn and/or Fe ions and a ligand such as 1,4,7-trimethyl-1,4,7-triazacyclonane shows better resistance of the bleach catalyst against discoloration during storage than a similar composition...
A new method describing the in situ synthesis of azo dyes in the mesopores of acidic faujasites is presented, where the coupling component N,N-dimethylaniline is adsorbed by interaction with the acidic centers, and zinc double salts of diazo compounds are added in weak acidic solution. Ship-in-the-bottle synthesis is achieved for azo dyes where the largest dimension of one component, i.e., approximately...
m-Xylene is separated from a mixture of C 8 aromatic hydrocarbons (e.g., a raffinate from a p-xylene plant) by chromatography and distillation. Toluene (desorbent) and a mixture of C 8 aromatic hydrocarbons containing m-xylene are applied to a chromatographic separation apparatus packed with a zeolite strongly adsorbing m-xylene for separating the mixture into them -xylene fraction...
The catalyst comprises a surface-modified crystalline aluminosilicate zeolite, such as a ZSM-5-type zeolite in a matrix or binder, such as alumina, having a specified metal content. The process is especially useful for dewaxing lubricating oil basestocks.
Fibers are immersed in an aqueous dispersion of superfine zeolite particles (average diameter 0.01-1.5 μm) and used as antibacterial or adsorbent fibers. Cotton, polyester, or acrylic fibers treated with cationic surfactants were dipped into an aqueous dispersion of zeolite Y (average diameter 0.657 μm) to absorb 26.6, 14.8, and 22.7 mg of zeolite Y/10 g of fiber, respectively, with good washfastness...
Pressure swing adsorption for the separation of air and other gases is carried out using specific preferred zeolite adsorbent compositions based on the symmetry of the framework atoms and cations. Particular SiO 2 /Al 2 O 3 and cation/cation ratios for enhanced performance are specified, especially LiX (SiO 2 /Al 2 O 3 ratio 2.0, 2.8, 2.364), CaLiX...
A process for the manufacture of zeolite crystal membranes comprises impregnating Al 2 O 3 substrates with slurries containing zeolite crystals in binder solutions; optionally washing and drying the substrates; and hydrothermally reacting the substrates containing adhered zeolite crystals by immersion in a solution containing zeolite precursor raw materials. The binders may be water...
m-Xylene is recovered from a mixture of C 8 aromatic hydrocarbons including PhEt and 2 other xylenes by liquid phase adsorptive separation using a Na, or Na- and Li-exchanged Y zeolite as the adsorbent. Performance is improved by maintaining the adsorbent in narrow ranges of temperature and hydration. PhMe is the preferred desorbent.
The catalyst comprises a first catalyst from Pt, Pd, and Ir and their oxides, at 0.1-10 g/l catalyst supported on silica-boria-alumina composite oxides and zeolites with silica/alumina molar ratio >30. It may further comprise one of Au, Ag, Cu, Fe, Sb, Se, Te, and Ta and their oxides as a 2nd catalyst, at 0.01-5 g/l catalyst, and 2nd/1st catalyst support weight ratio <1. The catalyst is...
Low sulfur gasoline of relatively high octane number is produced from a catalytically cracked, sulfur-containing naphtha by hydrodesulfurization followed by treatment over an acidic catalyst comprising zeolite β. The treatment over the acidic catalyst in the second step restores the octane loss that takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product...
A process is described for producing alkyl tertiary-alkyl ethers in one step which comprises reacting tertiary-butanol with an alkanol in the presence of a catalyst which exhibits extended life comprising β-zeolite modified with one or more metals selected from groups IA (especially Li) and IIIB (especially rare earth) of the Periodic Table and continuously contacting the alkanol and tertiary-butanol...
The process for the manufacture of A-type zeolites comprises heating mixtures containing fly ash and solid NaOH at 90-180°C for 60 min, preferably at 100-150°C for 5-20 h, to obtain a slurry; mixing with more NaOH and water; and hydrothermally reacting the slurry. The mixtures may contain 5:1-1:2 (weight ratio) of fly ash and solid NaOH. The fly ash may contain 15% Al 2 O 3 ...
Y-type zeolites with mesopore volume of 0.05 to 0.6 cm 3 /g (derived from pores of 2 to 60 nm diameter) are prepared by hydrothermal treatment of Y zeolites with an aqueous solution containing dissolved salts, acids, bases, or water-soluble organic compounds at a temperature greater than the atmospheric boiling point of the solution. The mesopore volume of the hydrothermally treated...
High cobalt-containing CoAPO-34 has been synthesized using tetraethylammonium hydroxide (TEAOH) and [(CH 3 CH 2 ) 4 N] 2 CoCl 4 as a cobalt source and additional templating agent. Pure CoAPO-34 was obtained by replacing up to 0.4 mol fraction of the aluminum by cobalt in the reaction gel at varying template concentrations. The crystallization of CoAPO-34 with...
The alkylation of benzene with dodecene over HY zeolite is studied in a stirred batch reactor. A special feature of the effect of the benzene to dodecene ratio on the reaction conversion is found. Even a low water content (0.04%) in the reactants greatly decreases the reaction conversion. The catalyst is deactivated quickly because of the coke formation in the zeolite. A special method of regenerating...
β-Zeolites are synthesized by using a directing agent prepared by dissolving an Al salt (preferably NaAlO 2 ) in an aqueous solution containing a tetraethylammonium hydroxide (TEAOH) template and NaOH and adding activated SIO 2 . The directing agent has a composition expressed in terms of oxide mol ratios:SiO 2 Al 2 O 3 = 20-120, TEAOH/SiO 2 = 0.2-0...
An adsorber containing refractory zeolites, for example, dealuminated mordenite, dealuminated zeolite Y, and/or zeolite ZSM-5 with SiO 2 Al 2 O 3 molar ratios of >8 is used to remove Pb, P, S, Zn, and other contaminants from the exhaust gases. The adsorbents may be doped with Cu, Fe, Na, and/or K or may be in the acid H-form.
A process for preparing a crystalline metallosilicate for use as a catalyst includes the steps of: forming a mixture of at least one nonalkali metal, a templating agent, and an organic base; adding a silicon additive to the mixture so as to form a metallosilicate hydrogel; aging the hydrogel to obtain a crystalline metallosilicate composition; and washing, drying, and then calcining the crystalline...
Aluminosilicate zeolite LZ-277 is synthesized hydrothermally from aqueous Na 2 O-Al 2 O 3 -SiO 2 gels in the absence of an organic templating agent. The as-synthesized LZ-277 has a chemical composition on an anhydrous basis expressed in terms of molar oxide ratios of (1.0 ± 0.1)Na 2 O:Al 2 O 3 :(3-16)SiO 2 and has a low adsorptive capacity...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.