Patent ID: 6074975
Filing Date: 2000-06-13
Classification: B01J

Abstract:
A process of making a composition consisting essentially of the steps of: (1) contacting an acid-leached ZSM-5 with a phosphorus compound selected from the group consisting of phosphorus oxide, phosphorus pentoxides, phosphorus oxychloride, phosphoric acid, phosphines, phosphites, phosphates, and combinations of two or more thereof to incorporate said phosphorus compound into said acid-leached ZSM-5 to produce a first promoted ZSM-5; (2) contacting said first promoted ZSM-5 with a second promoter to incorporate said second promoter into said first promoted ZSM-5 to produce a second promoted ZSM-5; and (3) heat-treating said second promoted ZSM-5 wherein said second promoter is a zinc compound selected from the group consisting of zinc nitrate, zinc titanate, zinc silicate, zinc borate, zinc fluorosilicate, zinc fluorotitanate, zinc molybdate, zinc chromate, zinc tungstate, zinc zirconate, zinc chromite, zinc aluminate, zinc phosphate, zinc acetate dihydrate, diethylzinc, zinc 2-ethylhexanoate, and combinations of two or more thereof; and further wherein said acid-leached ZSM-5 is a ZSM-5 having been suspended in an acid solution wherein said solution has a concentration of said ZSM-5 in said solution in the range of from about 0.01 to about 700 grams per liter, and further wherein said solution has an initial pH lower than about 6 and said solution is subjected to a treatment at a temperature in the range of about 70.degree. C. to about 120.degree. C. for 30 minutes to 20 hours at a pressure of about 1 atm.