Molecular sieve SSZ-93, catalyst, and methods of use thereof
AssigneeChevron U.S.A. Inc.
InventorsAdeola Florence Ojo, Yihua Zhang, Guan-Dao Lei, Howard S. Lacheen
Life of this patent
Estimating the term…
Abstract
The present application pertains to family of new crystalline molecular sieves designated SSZ-93. Molecular sieve SSZ-93 is structurally similar to sieves falling within the MTT structure type such as SSZ-32x, SSZ-32, ZSM-23, EU-13, ISI-4, and KZ-1 family of molecular sieves. SSZ-93 is characterized as having magnesium.
Claims25
A molecular sieve comprising an MTT-type framework, a mole ratio of from about 20 to about 72 of silicon oxide to aluminum oxide, a total micropore volume of between 0.005 and 0.04 cc/g;
- and magnesium;
- wherein, the molecular sieve comprises one or more of the following conditions:
- the magnesium comprises magnesium oxide and the molecular sieve comprises a magnesium oxide to silicon dioxide ratio of from about 0.005 to about 0.4, or from about 0.01 to about 0.25, or from about 0.04 to about 0.22, or from about 0.05 to about 0.2;
- or
- the molecular sieve has less ammonia desorbing above 300° C. than a comparable molecular sieve lacking magnesium in an ammonia temperature programmed desorption test;
- or
- the molecular sieve exhibits an FTIR vibrational mode at 3670 cm−1 and 3700 cm−1;
- or
- the molecular sieve exhibits an FTIR vibrational mode at 3600 cm−1 before exposure to pyridine that is not present upon exposure to pyridine;
- or
- the molecular sieve has an external surface area of 260-300 m2/g and a BET surface area of 350-370 m2/g.
A method of preparing a molecular sieve comprising an MTT-type framework, a mole ratio of from about 20 to about 72 of silicon oxide to aluminum oxide, a total micropore volume of between 0.005 and 0.04 cc/g;
- and magnesium, the method comprising:
- (a) preparing a reaction mixture containing:
- at least one source of silicon, at least one source of aluminum, at least one source of an element selected from Groups 1 and 2 of the Periodic Table, at least one source of magnesium, hydroxide ions, hexamethonium cations, and water;
- and
- (b) subjecting the reaction mixture to crystallization conditions sufficient to form crystals of the molecular sieve.
A process for converting hydrocarbons, comprising contacting a hydrocarbonaceous feed under hydrocarbon converting conditions with a catalyst comprising a molecular sieve, the molecular sieve comprising an MTT-type framework, a mole ratio of from about 20 to about 72 of silicon oxide to aluminum oxide, a total micropore volume of between 0.005 and 0.04 cc/g, and magnesium;
- optionally,
- wherein, the magnesium comprises magnesium oxide and the molecular sieve comprises a magnesium oxide to silicon dioxide ratio of from about 0.005 to about 0.4, or from about 0.01 to about 0.25, or from about 0.04 to about 0.22, or from about 0.05 to about 0.2.
A method of preparing molecular sieve SSZ-93, comprising:
- (a) preparing a reaction mixture comprising:
- (i) at least one active source of silicon;
- (ii) at least one active source of aluminum;
- (iii) at least one active source of magnesium;
- (iv) at least one active source of an alkali metal;
- (v) hydroxide ions;
- and
- (vi) an organic templating agent having the structure:
- wherein R is a C1-C5 alkyl group and A is an anion which is not detrimental to the crystallization of the molecular sieve;
- and
- (b) maintaining the reaction mixture under conditions sufficient to form crystals of the molecular sieve wherein the molecular sieve is prepared in the absence of an amine component;
- (c) recovering the crystals of the molecular sieve;
- wherein the molecular sieve has, in the calcined form, an X-ray diffraction pattern substantially as shown in the following Table:
- Relative
- Absolute
- 2-Theta(a)
- d-spacing
- Intensity
- (Degrees)
- (Angstroms)
- (%)(b)
- 8.22
- 10.749
- m
- 8.98
- 9.837
- w
- 11.52
- 7.674
- m
- 16.02
- 5.528
- vw
- 16.54
- 5.356
- w
- 18.36
- 4.828
- w
- 18.78
- 4.721
- m
- 19.80
- 4.480
- vs
- 21.10
- 4.207
- vs
- 21.58
- 4.115
- m
- 23.02
- 3.860
- vs
- 24.14
- 3.684
- vs
- 24.78
- 3.590
- vs
- 25.35
- 3.511
- s
- 26.14
- 3.406
- s
- 27.18
- 3.278
- w
- 28.32
- 3.148
- w
- 29.66
- 3.010
- w
- 31.80
- 2.812
- w
- 35.50
- 2.527
- m
- 36.62
- 2.452
- w
- 37.82
- 2.377
- w
- 38.24
- 2.352
- m
- (a)±0.20
- (b)The powder XRD patterns provided are based on a relative intensity scale in which the strongest line in the X-ray pattern is assigned a value of 100:
- vw = very weak (>0 to <10);
- w = weak (10 to ≤20);
- m = medium (>20 to ≤40);
- s = strong (>40 to ≤60);
- vs = very strong (>60 to ≤100).
Dependencies are inferred from the claim text.