RECOVERY OF ORGANIC SOLVENT FROM SMALL AMOUNT OF GAS CONTAINING ORGANIC SOLVENT IN HIGH CONCENTRATION

PROBLEM TO BE SOLVED: To efficiently recover org. solvent gas from a small amt. of highly conc. org. solvent - containing gas. SOLUTION: A drying process introducing drying gas containing no org. solvent into an activated carbon tank in order to dry and cool the activated carbon tank 1A, 1B or 1C after a desorbing process is performed. In the drying process, the introduction of org. solvent containing gas into the activated carbon tanks 1A-1C is started after the max. humidity peaks and max. temp. peaks of the outlet gases of the activated carbon tanks 1A-1C pass. At a point of time when the adsorbing capacity of activated carbon fibers is almost restored in an adsorbing process, the continued drying process is cut off to perform only the adsorbing process and a desorbing process is subsequently performed. Three activated carbon tanks 1A-1C are pref. used and, at a point of time when the drying process in one activated carbon process is completed, one activated carbon bed 1B among other two activated carbon tanks enters the drying process and the adsorbing and drying processes of one activated carbon tank 1B are successively changed over to those of the activated carbon tank 1C to continuously recover an org. solvent.