Improvements in or relating to method for separating the components of gaseous mixtures mixtures in fluidized adsorption system

摘要

Gaseous components of a mixture are separated by means of a fluidized solid adsorbent by passing said mixture into the absorption section of a column consisting from top to bottom of sections for (a) disengaging, cooling, absorption, rectifying, desorption and dehydration, or for (b) disengaging, adsorption, rectification desorption, dehydration and cooling, whilst the adsorbent passes downwardly through said sections. Tail gas is passed from the disengaging section to the dehydrating section (in arrangement (b), via the cooling section) to contact the wet adsorbent passing therethrough, and is also used to recirculate by entrainment the adsorbent from the lowest section to the disengaging section; in arrangement (b) part of this gas is withdrawn as the less adsorbed product gas but in arrangement (a) the latter is withdrawn from the upper part of the adsorption section; from the rectifying section an intermediate fraction or fractions, if present, are withdrawn; heat and stripping steam are applied to the desorption section, and steam and the more adsorbable component withdrawn therefrom; from the dehydrating section, a stream of mixed gases and steam is withdrawn, which may be added after drying to the tail gases from the disengaging section; all or a part of said mixed gases may alternatively in arrangement (a) be introduced into an intermediate section of the adsorption section. In one embodiment of arrangement (a), gas in addition to that required as less adsorbed product is withdrawn from the adsorption section and added to the tail gas, and this mixture used to assist fluidization in the cooling zone in addition to its use for dehydration and recirculation. It is stated that the whole of the wet product gases may be removed from the desorption section, dried and returned to the rectification section after removal of heavy fractions, in arrangement (a). Mixtures to which the process can be applied are:- separations between individual hydrocarbons as in residual gases from cracking of all kinds, separation of gases such as hydrogen and nitrogen from hydrocarbons (activated carbon adsorbent may be used), particularly the products of hydroforming; benzene and an inert carrier such as air, hydrogen and nitrogen; nitrogen and methane.