Abstract: Particulate adsorbents composed of inorganic oxides impregnated with an indicator dye selected from the group consisting of phenolphthalein, cresol red and thymol blue; a method for the production thereof, and a method for adsorptive drying of neutral gases using the aforementioned particulate adsorbents, whereby the degree of water absorption by the adsorbent particles is indicated by a reversible color change.

Abstract: A process for separating organic compounds, such as solvents, from gases, e.g. waste gases of paint shops. The gases to be treated are conducted in an adsorber over a sorbent which is composed of particulate activated carbon in an oxidic carrier. The charged sorbent is regenerated by passing therethrough, preferably according to the countercurrent principle, a heated regeneration gas, the regeneration gas charged with desorbate is cooled so that organic compounds condense and can then be separated, whereupon the regeneration gas is reheated and reused for the desorption of the charged sorbent. Heating of the regeneration gas as well as cooling of the regeneration gas charged with desorbate are, at least partially, effected by a heat pump. It will be expedient to provide at least two adsorbers which are charged and regenerated alternately. An apparatus for carrying out the process is additionally described.

Abstract: Described is a process for the simultaneous sorption of water and organic compounds from gases selected from the group comprising natural gas and process gases (e.g. waste gases of maleic acid or terephthalic acid (anhydride) production or phthalic acid anhydride production or of steam reforming). The gas to be treated is contacted with a sorbent comprising particulate activated carbon in an oxidic carrier on a basis of silicon dioxide, aluminum oxide, aluminum phosphate or aluminosilicate. When natural gas is treated, water and C5+ hydrocarbons, for example, can be separated simultaneously. In steam reforming, with appropriate process management, C2+ hydrocarbons, CO.sub.2 and water can be absorbed simultaneously.

Abstract: Particulate adsorbents composed of inorganic oxides impregnated with an indicator dye selected from the group consisting of phenolphthalein, cresol red and thymol blue; a method for the production thereof, and a method for adsorptive drying of neutral gases using the aforementioned particulate adsorbents, whereby the degree of water absorption by the adsorbent particles is indicated by a reversible color change.

Abstract: A method for the sorption of organic compounds using a sorbent, comprising activated carbon in a preferably amorphous oxidic support is described. Novel sorbents are also described.