Process for the preparation of catalysts comprising a pentasil-type zeolite
View Patent ↗A process for the preparation of a composition comprising a pentasil-type zeolite, which process comprises the following steps: a) hydrothermally treating an aqueous slurry comprising an aluminium source, a silicon source, a seeding material, and optionally a divalent metal source, thereby forming a pentasil-type zeolite and at least one other compound, and b) shaping the product of step a). Examples of the at least one other compound are anionic clay, cationic clay, Si—Al cogel, and (pseudo)boehmite.
1. A process for the preparation of a composition comprising a pentasil-type zeolite, which process comprises the steps of:
a) hydrothermally treating an aqueous slurry comprising an aluminium source, a silicon source, a seeding material, and optionally a divalent metal source, thereby forming a pentasil-type zeolite and at least one other compound selected from the group consisting of anionic clay, cationic clay, Si—Al cogel, and (pseudo)boehmite, and
b) shaping the product of step a).
2. The process of claim 1 wherein the pentasil-type zeolite is a ZSM-type zeolite or zeolite beta.
3. The process of claim 1 wherein a doped seed is used as the seeding material in step a).
4. The process of claim 1 wherein step a) comprises mixing of an aluminium source, a silicon source, a seeding material, and a divalent metal source in a slurry, and wherein the divalent metal source is a magnesium source.
5. The process of claim 1 wherein the magnesium source is selected from the group consisting of MgO, Mg(OH) 2 , hydromagnesite, magnesium carbonate, magnesium hydroxycarbonate, Mg-acetate, Mg-hydroxy-acetate, and mixtures thereof.
6. The process of claim 1 wherein the aluminium source is selected from the group consisting of aluminium trihydrate, flash-calcined aluminium trihydrate, boehmite, pseudoboehmite, aluminium sol, amorphous alumina, gel alumina, transition alumina, and mixtures thereof.
7. The process of claim 1 wherein the silicon source is sodium (meta) silicate, silica sol, or a mixture thereof.
8. The process of claim 1 wherein step a) is performed continuously in a series of at least two reaction vessels.
9. The process of claim 1 wherein step a) comprises mixing of an aluminium source, a silicon source, a seeding material, and a divalent metal source in a slurry, thereby forming a pentasil-type zeolite and an anionic or cationic clay as the other compound.
10. The process of claim 1 wherein step a) comprises mixing of a silicon source, an excess of aluminium source, and a seeding material, thereby forming a pentasil-type zeolite and (pseudo)boehmite as the other compound.