Patent ID: 6020281
Filing Date: 2000-02-01
Classification: B01D,B01J,C09K,F25B

Abstract:
A desiccant suitable for use with refrigerants comprising difluoromethane which consists essentially of a modified form of zeolite A prepared by the steps of:a. potassium ion-exchanging zeolite A to provide an ion-exchanged zeolite A to a level greater than about 60 percent of a available sodium cations;b. agglomerating said ion-exchanged zeolite A with clay binder selected from the group consisting of attapulgite, kaolin, volclay, sepiolite, halloysite, palygorskite, ball clays, bentonite, montmorillonite, illite, chlorite, and mixtures thereof to produce a zeolite agglomerate; andc. pore-reducing said zeolite agglomerate in the presence of steam to provide a pore-reduced agglomerate having a water adsorption capacity greater than about 15 weight percent and essentially without a difluoromethane adsorption capacity.