초록 ▼

The invention includes a ZSM-5 composition and the preparation thereof which comprises treating ZSM-5 with solutions of salts of weak acids. The resulting ultrasmall crystal size ZSM-5 component has a sorption capacity for 2,2-dimethylbutane of at least 10 mg/g zeolite and a sorption time for 30% ca

The invention includes a ZSM-5 composition and the preparation thereof which comprises treating ZSM-5 with solutions of salts of weak acids. The resulting ultrasmall crystal size ZSM-5 component has a sorption capacity for 2,2-dimethylbutane of at least 10 mg/g zeolite and a sorption time for 30% capacity zeolitic sorption at 60°C. and P(2,2-dimethylbutane) of 60 torr, of less than about 4 minutes.

대표청구항 ▼

A process for producing ultra small crystals of ZSM-5 consisting essentially of the steps of: (a) providing a sample consisting of an unbound, neat, fresh, and unspent ZSM-5 zeolite free of non-framework aluminum having (i) a framework silica:alumina mole ratio of at least 30:1, (ii) a crystal size

A process for producing ultra small crystals of ZSM-5 consisting essentially of the steps of: (a) providing a sample consisting of an unbound, neat, fresh, and unspent ZSM-5 zeolite free of non-framework aluminum having (i) a framework silica:alumina mole ratio of at least 30:1, (ii) a crystal size at least 0.02 micron, (iii) a sorption time, t0.3, of greater than four minutes, wherein t0.3 is the time required to sorb 30% of the sorption capacity for 2,2-dimethylbutane measured at 60°C. and a partial pressure for 2,2-dimethylbutane of 60 torr; (b) contacting the sample under hydrothermal conditions, with a solution of alkali metal carbonate, said solution having a pH greater than about 8, said hydrothermal conditions being effective to remove framework silica from said zeolite to produce a product with a framework silica:alumina mole ratio less than that of the sample, an ion exchange capacity greater than that of the sample, and a t0.3 value of less than about 4 minutes; (c) recovering said product of ultra small crystals of ZSM-5.