Patent ID: 7553790

Claim:
A method to improve the properties of a ZSM-5 zeolite catalyst consisting essentially of the following steps in order: a. treating said catalyst with a first potassium salt solution, b. decanting said first potassium salt solution from said catalyst, c. treating said catalyst with a second potassium salt solution, d. decanting said second potassium salt solution from said catalyst, e. treating said catalyst with a third potassium salt solution, f. decanting said third potassium salt solution from said catalyst, g. performing a hybrid calcination upon said catalyst wherein the catalyst is subjected to a first heat treatment in a nitrogen atmosphere at a temperature of about 200 to 760° C., then held at that temperature for about 1 hour, followed by a second heat treatment at a temperature of about 200 to about 820° C. for a period of about 1 hour to about 100 hours in an atmosphere selected from the group consisting of: aa) substantially pure nitrogen, bb) substantially all air, and cc) a combination of substantially pure nitrogen and air, h. treating said hybrid calcined catalyst with an ammonium salt solution, i. decanting said ammonium salt solution from said treated calcined catalyst, and j. calcining said catalyst in air at a temperature of about 480° C. to about 600° C.