Crystalline zeolite composition (ECR-5) having a cancrinite-like structure and process for its preparation
AssigneeExxon Research & Engineering Co.
InventorDavid E. W. Vaughan
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Abstract
A crystalline zeolite may be prepared which has a composition, in terms of mole ratios of oxides, in the range: 1.0 to 1.3 Na.sub.2 O:Al.sub.2 O.sub.3 :2.1 to 8.0 SiO.sub.2 and having a cancrinite-like structure in which the twelveing channel thereof is not blocked by, for example, salt molecules. The preferred compositions are of the formula: 1.1 to 1.3 Na.sub.2 O:Al.sub.2 O.sub.3 :2.4 to 3.1 SiO.sub.2 This zeolite may be prepared from crystallization of an aged reaction mixture containing aqueous ammonia, a source of silica, a source of alumina and sodium hydroxide.
Claims13
A crystalline zeolite, being isostructural to cancrinite, in which the twelve-ring channel has a sorption of greater than about 1% by weight hexane, said crystalline zeolite having a composition, in terms of mole ratios of oxides in the range:
- 1.0 to 1.3 Na.sub.2 O:Al.sub.2 O.sub.3 :2.1 to 8.0 SiO.sub.2.
A process for preparing a crystalline zeolite having a composition, in terms of mole ratios of oxides, in the range:
- 1.0 to 1.3 Na.sub.2 O:Al.sub.2 O.sub.3 :2.1 to 8.0 SiO.sub.2
- and being isostructural to cancrinite, in which the twelve-ring channel thereof has a sorption of greater than about 1% by weight hexane, comprising the steps of:
- (a) preparing a reaction mixture comprising aqueous ammonia, a source of silica-alumina, and sodium hydroxide, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:
- Na.sub.2 O:Al.sub.2 O.sub.3 :2 to 17
- SiO.sub.2 :Al.sub.2 O.sub.3 :2 to 25
- H.sub.2 O:Al.sub.2 O.sub.3 :30 to 450
- (H.sub.2 O+NH.sub.3):Al.sub.2 O.sub.3 :50 to 600
- wherein the ammonia is present in the reaction mixture in an amount of 15 to 30 percent, based on total moles of H.sub.2 O;
- and
- (b) maintaining the reaction mixture at a temperature between about 70.degree. and 180.degree. C. and for a time of about 1 to 10 days.
A process for preparing a crystalline zeolite having a composition, in terms of mole ratios of oxides, in the range:
- 1.0 to 1.3 Na.sub.2 O.sub.3 :Al.sub.2 O.sub.3 :2.2 to 6.0 SiO.sub.2
- and being isostructural with cancrinite, in which the twelve-ring channel thereof has a sorption greater than about 1% by weight hexane, which process comprises:
- (a) preparing a reaction mixture comprising aqueous ammonia, a preformed alumina-silica gel having a Al/Si ratio of 1 to 10, and sodium hydroxide, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:
- Na.sub.2 O:Al.sub.2 O.sub.3 :2.0 to 17
- SiO.sub.2 :Al.sub.2 O.sub.3 :2 to 25
- H.sub.2 O:Al.sub.2 O.sub.3 :30 to 450
- (H.sub.2 O+NH.sub.3):Al.sub.2 O.sub.3 :50 to 600
- wherein the aqueous ammonia is present in the reaction mixture in an amount of about 15 to 30 percent, based on total moles of H.sub.2 O;
- (b) blending the reaction mixture sufficiently to form a substantially homogeneous mixture;
- and
- (c) maintaining the reaction mixture at a temperature of 70.degree. to 180.degree. C. for 1 to 10 days until crystals of the zeolite are formed.
A process for preparing a crystalline cancrinite zeolite in which the twelve-ring channel thereof has a sorption greater than about 1% by weight hexane, which process comprises the steps of:
- (a) preparing a reaction mixture comprising aqueous ammonia, a source of silica, metakaolin, sodium hydroxide, said reaction mixture having a composition, in terms of mole ratio of oxides, within the following ranges:
- Na.sub.2 O:Al.sub.2 O.sub.3 :2 to 17
- SiO.sub.2 :Al.sub.2 O.sub.3 :2 to 25
- H.sub.2 O:Al.sub.2 O.sub.3 :30 to 450
- (H.sub.2 O+NH.sub.3):Al.sub.2 O.sub.3 :50 to 600
- wherein the ammonia is present in the reaction mixture in an amount of 15 to 30 percent, based on total moles of H.sub.2 O;
- and
- (b) maintaining the reaction mixture at a temperature between about 70.degree. and 180.degree. C. for 1 to 10 days until crystals of the zeolite are formed.
Dependencies are inferred from the claim text.