METHOD OF TREATING OR RECOVERING GASEOUS HYDROCARBON CONTAINED IN WASTE GAS

摘要

A method of treating gaseous hydrocarbon contained in a waste gas using a single column type or multi-column type adsorbent layer, characterized in that: (1) the adsorption apparatus in use comprises a double cylinder type or multi-cylinder type adsorption apparatus adapted to cool the adsorbent layers indirectly with cooling water, (2) the adsorbent layers comprise a filler of one or not less than two kinds out of activated carbon, synthetic zeolite and hydrophobic silica gel, (3) the time for switching between the adsorption operation and the desorption operation with respect to the adsorbent layers is set to 1-15 minutes, (4) during the desorption operation, evacuation is carried out as the purging is done by using a part of the clean gas discharged from the adsorbent layers and/or air, (5) gaseous hydrocarbon is recovered from the purge waste gas. This method enables an abnormal temperature rise in the adsorbent layers to be prevented, and the safety of the apparatus to be improved. The method also enables the concentration of the residual hydrocarbon in the gas discharged to the atmospheric air to be reduced to not more than 1 vol%.