초록 ▼

The invention relates to faujasite-containing compositions in which the original hydrogen or monovalent forms are ion exchanged to their polyvalent form and then thermally activated to promote dehydration and dehydroxylation of the faujasite while maintaining substantially the same zeolite content.

The invention relates to faujasite-containing compositions in which the original hydrogen or monovalent forms are ion exchanged to their polyvalent form and then thermally activated to promote dehydration and dehydroxylation of the faujasite while maintaining substantially the same zeolite content. The resulting compositions containing faujasites substantially in their dehydrated/dehydroxylated state have been found to have surprisingly high selectivities and capacities for the separation of air into nitrogen and oxygen.

대표청구항 ▼

A polyvalent ion exchanged adsorbent composition comprising at least 50% by weight faujasite and the faujasite portion thereof having a majority of its exchangeable ion capacity in the polyvalent form prepared by aprocess which comprises: (a) ion exchanging said faujasite-containing composition with

A polyvalent ion exchanged adsorbent composition comprising at least 50% by weight faujasite and the faujasite portion thereof having a majority of its exchangeable ion capacity in the polyvalent form prepared by aprocess which comprises: (a) ion exchanging said faujasite-containing composition with polyvalent ions, and (b) thermally activating the polyvalent exchanged composition to remove a substantial portion of its zeolitic water in said composition in such a manner as to produce a preponderance of said polyvalent ions in a dehydrated/dehydroxylated state under conditions to minimize the water vapor pressure throughout this step by subjecting the polyvalent exchange composition containing up to about 30% by weight of water to pressures in the range of about 0.1 to 10 atmospheres while maintaining a flow of a non-reactive purge gas at a molar mass velocity of about 0.5 to 100 kg. mole/m2-hr. and a residence time of no greater than about 2.5 minutes, heating said composition at a temperature ramp of 0.1°to 40°C./min. up to temperatures at least about 300°C. and no greater than 650°C. and maintaining said composition at these temperatures for a period such that the resulting nitrogen capacity and selectivity ratio of the resulting polyvalent exchanged composition for the separation of a binary mixture of oxygen and nitrogen is substantially greater than such a polyvalent ion exchanged composition that has not undergone such a thermal activation step. The use of the composition of claim 1 in the separation of air into nitrogen and oxygen.