Process for large-crystal zeolite manufacture

Process for large-crystal zeolite manufacture

As in previous issues, a selection of the more interesting patents that have been published recently is given below under the headings: synthesis, cat...

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As in previous issues, a selection of the more interesting patents that have been published recently is given below under the headings: synthesis, catalysis, separation processes, detergents and miscellaneous applications.

J.A. Barton

SYNTHESIS Crystalline

silicophosphoaluminates

E. G. Derouane; Mobil Oil Corp. U.S. 4,647,442,

R. von Mar.

Ballmoos

3, 1987;

Appl.

Dec.

19, 1963

Crystalline silicophospho’aluminates (designated MCM-2, structurally analogous to the zeolite chabazite) are prepared solvothermally from a 2-phase reaction mixture consisting of an organic phase immiscible with water and containing a Si source, an aqueous phase containing dissolved or partially dissnlved Al phosphate (type AlPOd-5), and a EtN+ directing agent. These materials are characterized by a given X-ray diffraction pattern and show a variety of catalytic properties.

Large

crystal

M. Kurihara; New Fuel Jpn Kokai

A paulingite-like

Research 6, 1987;

Association Appl. Aug.

28,

1985

synthetic

zeolite

D. E. W. Vaughan and Engineering Co. 213,739, Mar. 11, 1987;

U.S.

Appl.

July

29,

1985

A synthetic zeolite designated ECR-18, with faujasitic paulingite-like structure has the composition: (TEA,Na)zO:(AI,Ga)z03:3-20 SiOz (TEA = NEtd+) and is prepared by hydrothermal methods from a reaction mixture of mol composition NazO:AlzOz 0.4-3.4, (TEA)zO:AlzOs 0.8-4.5, SiOz:AlzOs 4-22, and HzO:AlzOs 86-360, with the optional inclusion of, e.g., 0.1-10 mol% (vsfinai total AlzOsj seed crystals. The zeolite is further defined in terms of its X-ray diffraction pattern, which is given.

structure

zeolite

F. Raatz; C. Marcilly; P. Dufresne lnstitut Franqais du Petrole Eur. Pat. Appl. 214,042, Mar. 11, 1987;

Fr. Appl.

Sep.

4, 1985

Dealuminated omega zeolites are characterized by a 2 1O:l SiOz/AlzOs bulk mol ratio, c 0.5 wt.% Na (in zeolite calcined at 1100°C). unit cell measurements 0.759 x 1.814 nm, and a N adsorption capacity of > 5 wt.% (measured at 77 K at a partial pressure of P/P, 0.19). After initial preparation to form a zeolite (Sioz/AlzOz mol ratio 6lO:l), alkali and organic cations are removed, the zeolite is calcined, and treated with an acid to increase the SiOz/AlzOs mol ratio to 2 10: 1.

160

L

Patents 219,354,

Inc. Apr. 22,

1987;

U.K.

Appl.

Oct.

15, 1985

The zeolite L consists of cylindrical crystallites with basal planes and with ratio of the axial length of the curved cylindrical surface to the overall axial length of the crystallite > 0.9. The zeolite is prepared from water, a source of alkali metal (M’), a source of Si, and a source of Al. The mixture contains an additional metal (M”), and the composition in molar ratios of oxides is (Mz’O + MU,“O)/SiOz = (0.18-6.36):1, HzO/(Mz’O + Ma,,“O) = (25-90):1, SiOz/AlzOs = (5-15):1, and Mz’OIfMz’O + Mu,,“01 = (0.9-6.9999):1 (M’ = alkali metal; M” = Mg, Ca, Ba, Mn, Cr, Co, Ni, or Zn; n = valence of M”). These zeolites are useful as a catalyst base for the dehydrocyclization of alkanes.

Process

for large-crystal

W. Hoelderich; BASF A.-G. Ger. Offer-r.

zeolite

manufacture

H. V. Schlimper 3,537,459,

Apr.

23,

1987;

Appl.

Oct.

22,

1985

Large, symmetrical pentasil-type zeolite crystals for conversion of organic compounds, e.g., of MeOH to hydrocarbons containing lower olefins and aromatic compounds, are prepared from highly dispersed SiOz from the combustion of Si chloride compounds, and 2 1 compound(s) of trivalent elements such as Al, B, Fe, Ga, and Cr.

Synthetic Technology 87.52.121, Mar.

Large crystal mordenite: xNaz0.yKz0.Alz03.zSiOz where x 2 0, y 2 0, x + y = 1,5 < z < 30 is manufactured from an aqueous mixture containing a Si source, an Al source, and Z 2 of a Na source, a K source, and an amino alcohol in the following mol ratios SiOz/AlzOs 2 20, NalSiOz 6-3, WSiOz &3, amino alcohol/SiOz g-10, and OH-/SiOz 0.05-6.5. The large crystal mordenite is effectively used for catalysts, catalyst supports and adsorbents.

Omega

zeolite

J. P. Verduijn Exxon Chemical Eur. Pat. Appl.

mordenite

K. Takatsu Oil Development Tokkyo Koho

K. G. Strohmaier; Exxon Research Eur. Pat. Appl.

Improved

ZEOLITES,

1988, Vol8,

March

mordenite

M. Harada; H. Miyazaki; K. ltabashi Toyo Soda Mfg. Co. Ltd. Eur. Pat. Appl. 216,312, Apr. 1, 1987;

Jpn.

Appl.

Sep.

20,

1985

Molded, synthetic mordenite is prepared by molding wetted mixtures of Si, Al, and alkali sources and mordenite seed crystals, heating the molded material, calcining it, and heating the calcined material in an aqueous Na silicate solution containing SiOz 7-25, and NazO 2-8 wt.%, and having a SiOz/NazO mol ratio of (O.w):l. This mordenite is useful as an adsorbent; it is of high purity and high crystallinity, as confirmed by X-ray diffraction: and the integrity of the molded material is not affected by the calcination.

Hexagonal

zeoliie

T. M. Wortel; Exxon Chemical Eur. Pat. Appl.

J. P. Verduijn Patents inc. 220,881, May

L

6, 1987;

U.K.

Appl.

Oct.

15, 1985

A gel having the molar composition 2.62K20:AIz0s:10Si0z: 158HzO was prepared by dissolving AI( in boiling 86% KOH to form solution A and correcting for water loss. Separately, solution B was prepared by diluting colloidal SiOz with water. The solutions were mixed to form a gel, and just before the gel became stiff it was placed in a Teflon-lined autoclave to effect crystallization. The product was highly crystalline zeolite L (by X-ray diffraction), free from contamination by zeolite W. Scanning electron micrographs showed the crystallites to be rods of hexagonal cross-section having a mean diameter of - 2 pm and an aspect ratio of 1-1.5. Zeolite L, in which the crystallites have a hexagonal cross-section, preferably being in the form of well-defined smooth-surface hexagonal rods with a mean diameter of 0.5-4 pm and an aspect ratio of 1-5, shows increased selectivity to CsHs when used as a catalyst substrate in the aromatization of Cs aliphatic hydrocarbons.

Synthesis

of zeolites

EM-22

and ZSM-23

D. J. Klocke; J. C. Vartuli; G. W. Kirker Mobil Oil Corp. Eur. Pat. Appl. 220,893, May 6, 1987; U.S. Zeolites mixtures

ZSM-22 containing

and

ZSM-23 an organic

are prepared directing

Appl.

Oct.

21, 1985

by crystallizing agent and a Clb

reaction alcohol or