GB292204A - An improved process for the separation of gases or vapours from gaseous mixtures - Google Patents

Abstract

292,204. Johnson, J. Y., (I. G. Farbenindustrie Akf.-Ges.). Dec. 10, 1926. Right to Patent relinquished. Gases, separating mixtures of.-For separating components of dry gas or vapour mixtures, or for drying humid gases which do not contain any readily adsorbable gas or vapour in addition to water vapour, two or more adsorbents of different structure are employed in succession, one at least of the adsorbents being of hydrophile character. Preferably, the mixture is first brought into contact with a wide-porous adsorbent capable of adsorbing such vapours with which the mixture is saturated and then with an adsorbent which is fine-porous and capable, of adsorbing to a high degree such vapours with which the mixture is charged to a low extent. When an adsorbate such as benzol is to be expelled by means of steam, it is preferable to use a wide-porous active, silica, diatomaceous earth or the like and preferably also in rear of a fine-porous gel. The water vapour used for expelling an adsorbate which has preferably been freed from water of condensation may be mixed with warm air or warm inert gas, such as nitrogen, hydrogen or coal gas. Hydrochloric acid contaminated with hydrocarbons, for example when chlorinating organic compounds, may thus be purified, and the hydrocarbons especially those of higher boiling points may be recovered from the adsorbents by expulsion with water vapour. Liquids or mixtures of liquids may be purified or fractionated by passing them in the state of vapour mixed with inert gas or not over combinations of adsorbents, or the latter may be conveyed in the opposite direction to the gas current. The whole or a portion of the adsorbents may be cooled, or the gaseous mixture may be cooled or compressed, or combinations of these methods may be adopted; in cases where condensation of vapours takes place, it is preferable to collect the condensate separately, prior to the adsorption. Examples of technical applications are the removal of water vapour or carbon dioxide from gases intended to be liquefied as in the Linde process; the drying of gases which are to be or have been compressed, such as compressed oxygen prior to being filled into cylinders; and the adsorption of sulphuretted hydrogen from illuminating gas or water gas containing air and ammonia. All kinds of active adsorbents may be used in combination, such as natural and artificial silica or silicates, natural and artificial zeolites such as chabasite, or alumina, active charcoal &c. Adsorbents with. pores of an intermediate size may be interposed between the fine-porous and wide-porous adsorbents. The adsorbents of a combination may differ chemically instead of or in addition to physically, as, for .example, combinations of a wide-porous charcoal and a fine-porous gel, or a wide-porous gel with fine-porous charcoal One kind of adsorbent mav be made of substances which are different chemically but have pores of the same order of dimensions. Each adsorbent may be placed in a separate vessel, or several or all of the adsorbents may be placed in one vessel. Numerical data of relative adsorptions in the case of hydrogen charged with benzol are given in the Specification. Reference has been directed by the Comptroller to Specification 255,655.