Absorption of vapour on e.g. activated carbon - with regeneration of adsorbent and recovery of adsorbed vapour

摘要

A process for removing gas or vapour from a carrier gas, by absorption on activated carbon, molecular sieves, silica gel or activated alumina in a first adsorber, followed by regeneration of the adsorbent by hot gas and cooling the hot gas and sending it to a second adsorber for recovery of the adsorbed gas or vapour, incorporates distributing the adsorbent in the first adsorber in several layers, passing the carrier gas through one layer only at a speed suitable for adsorption, but passing the hot gas for regeneration through all the layers. The flow rate of the hot gas for regeneration is of the same order as that of the carrier gas, and the whole of the hot gas leaving the first adsorber goes, after cooling, to the second adsorber. The process is partic. useful in removing small quantities of solvents which evaporate into the air in printing works and during many other industrial operations. It allows the gases to flow at the same stages, thus ensuring adequate gas distribution through the adsorbant, but the total flow of gas for desorption is much less, so that the gas giving to the second absorber contains a higher proportion of the vapour and the process is more efficient than existing ones.