Solvent vapour recovery in two successive absorption towers - with low compression eliminating explosion risk and freezing

摘要

A method of recovering a solvent vapour from a mixt. comprising solvent vapour and air is described. The gas mixt. retained in a storage vessel, is slightly compressed and then supplied to a first absorption column where a major part of the solvent vapour is recovered by gas-liquid contact absorption in contraflow witha first absorption agent, typically cooled gasoline liquid. The gas from the top of this first absorption column is conducted to a second absorption column and there brought into absorption gas-liquid contraflow contact with a cooled, circulating second absorption agent, typically a heavy, liquid hydrocarbon. Used in partic. for the extn. of solvent vapours which can lead to a substantial explosion risk.