GB811627A - Process and apparatus for the continuous separation of gas mixtures by means of gas chromatography - Google Patents

Abstract

In the separation of gaseous mixtures by the chromatographic method there is used a series of vertical absorbent columns rotatably mounted on a circular base provided with two chambers with which the columns may be brought into communication in succession, and also provided with a receiving head comprising a number of chambers to draw off the carrier gas, and components separately. One chamber at the base is supplied continuously with the carrier gas, and the other with the gas mixture to be separated. The sizes of the receiving and base chambers are co-ordinated with the separating capacity of each column so that the cycle of operations in each column is completed at each revolution of the battery of columns. For example, a circular tower of separating columns makes one complete revolution in 7 minutes, during which the inert gas and the slower moving component emerges at the top and is removed, followed by inert gas alone, and finally inert gas and the slower component. These gas mixtures are separately collected in the receiving chambers as each column is brought into communication therewith in turn. The initial charging and flow of first separated component may take up to several minutes, when only inert gas will appear at the exit to the column, for example, when CO2 is used as carrier gas. The process may be applied to multi-component mixtures by arranging a suitable number of receiving chambers for the separated components, each alternating with a receiving chamber for the carrier gas. In the case of difficultly condensible gases, absorbents such as activated carbon, silica gel or aluminium oxide are used, otherwise kieselguhr, or glass powder impregnated with a low vapour pressure liquid, e.g. a hydrocarbon oil, alcohol or a silicone oil is used.