Process for preparing crystalline zeolite composition ERC-2
AssigneeExxon Research & Engineering Co.
InventorDavid E. Vaughan
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Abstract
A synthetic crystalline zeolite is provided characterized by having a composition, in terms of mole ratios of oxides, in the range: 0.9 to 1.1 M.sub.2/n O:Al.sub.2 O.sub.3 :2.5 to 5.1 SiO.sub.2 :xH.sub.2 O wherein M is at least one exchangeable cation, n is the valence of M, and x is 0 to 6, and characterized by having a specified X-ray powder diffraction pattern. The zeolite may be prepared by crystallization from a reaction mixture of KOH (and optionally a minor amount of NaOH), water, a source of silica, and a source of alumina preferably derived from kaolin or halloysite. Most preferably, the source of alumina is metakaolin and the source of silica is potassium silicate.
Claims11
A process for preparing a crystalline zeolite having a composition, in terms of mole ratios of oxides, in the range:
- 0.9 to 1.1 M.sub.2 O:Al.sub.2 O.sub.3 :2.5 to 5.1 SiO.sub.2 :0 to 6 H.sub.2 O
- where M is K or a mixture of K and Na, where Na is no more than 30 mole percent of the mixture, and characterized by having an X-ray powder diffraction pattern essentially identical to that given in Table IV which is characteristic of zeolite L, which comprises:
- (a) preparing a reaction mixture comprising water, a source of silica, metakaolin, KOH and up to about 30 mole percent of NaOH based on total moles of KOH and NaOH, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:
- ______________________________________ M'.sub.2 O:Al.sub.2 O.sub.3 1.0 to 1.6 SiO.sub.2 :Al.sub.2 O.sub.3 2.5 to 5.1 H.sub.2 O:Al.sub.2 O.sub.3 80 to 140 ______________________________________
- where M' is either K or a mixture of K and Na;
- and
- (b) maintaining the reaction mixture at between about 140.degree. and 300.degree. C. under autogeneous pressure for a sufficient period of time so as to form crystals of the zeolite.
A process for preparing a crystalline zeolite having a composition, in terms of mole ratios of oxides, in the range:
- 0.9 to 1.1K.sub.2 O:Al.sub.2 O.sub.3 :2.8 to 4.8SiO.sub.2
- and having atoms arranged in a hexagonal unit cell such that the X-ray powder diffraction pattern of said zeolite is essentially identical to that given in Table IV, which comprises:
- (a) preparing a reaction mixture comprising KOH, water, potassium silicate and metakaolin, said reaction mixture having a composition, in terms of mole ratios of oxides, within the following ranges:
- ______________________________________ K.sub.2 O:Al.sub.2 O.sub.3 1.0 to 1.6 SiO.sub.2 :Al.sub.2 O.sub.3 3 to 5 H.sub.2 O:Al.sub.2 O.sub.3 90 to 120 ______________________________________
- (b) blending the reaction mixture sufficiently to form a substantially homogeneous mixture;
- and
- (c) maintaining the blended reaction mixture at between 160.degree. and 240.degree. C. under autogenous pressure for a sufficient period of time to form crystals of the zeolite.
Dependencies are inferred from the claim text.