Zeolite catalyst for skeletal isomerisation of olefins

A method for the manufacture of a zeolite catalyst, wherein the method comprises the following steps:

• a) preparing a gel mixture capable of forming crystalline material using a gel ripening pre-treatment step which is carried out by adding one or more sources of alkali or alkaline earth metal (M) selected from the group consisting of sodium, potassium, magnesium, and calcium to water whereby Solution A is obtained, then adding one or more sources of an oxide of a tetravalent element (Y) selected from the group consisting of silicon and germanium to Solution A with continuous stirring whereby Solution B is obtained, then preparing Solution C by adding a source of an oxide of a trivalent element (X) selected from the group consisting of aluminum and gallium to water and adding to the obtained mixture a directing agent (R) selected from pyrrolidine and diethanolamine, adding the obtained Solution C to Solution B to obtain a gel mixture, stirring the gel mixture, then adding sulfuric acid to adjust the pH to a range of 8.5-13.5 and stirring the mixture, said mixture having a composition, in terms of molar ratios, within the following ranges:
• Molar ratio
• Range
• YO2/X2O3
• 30 to 300
• H2O/YO2
• 20 to 100
• OH−/YO2
• 0.1 to 0.4
• M/YO2
• 0.05 to 1.0
• R/YO2
• 0.02 to 1.0
• b) carrying out hydrothermal synthesis wherein said mixture from step a) is maintained at a temperature from about 100° C. to about 250° C. under a dynamic mode of stirring until crystals of said material are formed, recovering the said material;
• and
• c) removing the directing agent (R) partly or totally with a stepwise calcination procedure wherein the temperature of the zeolite product obtained from step b) is raised to an intermediate temperature followed by raising the temperature to a final calcination temperature and obtaining a zeolite catalyst having a MTT structure with the following XRD pattern:
• D/n
• Intensity I/I0
• 10.8
• 42
• 9.95
• 16
• 7.77
• 37
• 4.507
• 90
• 4.241
• 79
• 3.88
• 100
• 3.704
• 80.