Abstract: The solvent vapor concentration which is mixed with air and is obtained in the treatment of articles in an apparatus is controlled in the apparatus by a method comprising the following steps:a) passing gaseous solvent vapor/air mixture from the apparatus through at least one adsorber containing an adsorbent for the organic solvent and recycling the outlet gas stream from the adsorber to the apparatus;b) after completion of the adsorption, opening the apparatus to enable removal of treated articles from the apparatus and closing the apparatus;c) heating the adsorbent and passing a gas stream from the apparatus through the adsorber and recycling the outlet stream from the adsorber directly to the apparatus.

Abstract: Organic materials, for example halocarbons, hydrocarbons or halogenated hydrocarbons are recovered from fluid streams, such as air or water, by passing these streams over post-cross-linked asdorptive porous resin beads. These beads have been prepared by(a) haloalkylating cross-linked copolymer beads of i) styrene or an alkylstyrene and ii) divinylbenzene and/or trivinylbenzene,(b) purifying the haloalkylated copolymer beads,(c) swelling the haloalkylated copolymer beads in an inert organic liquid and post-cross-linking the swollen beads in the presence of a Friedel-Crafts catalyst. The cross-linked copolymer beads which are used in the haloalkylation step are microporous copolymer beads of i) 99.8 to 98.2 weight percent of styrene or an alkylstyrene and ii) 0.2 to 1.8 weight percent of divinylbenzene and/or trivinylbenzene, based on the total weight of i) and ii).