Vapor recovery system

PCT No. PCT/GB97/01366 Sec. 371 Date Apr. 13, 1998 Sec. 102(e) Date Apr. 13, 1998 PCT Filed May 20, 1997 PCT Pub. No. WO96/41781 PCT Pub. Date Dec. 27, 1996Apparatus for recovering volatile organic compounds (VOC) from VOC/inert gas mixtures leaving tanker holds during crude oil loading includes an absorption column 12 in which incoming VOC is absorbed into cold kerosene, a portion of the VOC rich kerosene leaving the absorption column being cooled in a cooler 88 and returned to the absorption column to contact incoming VOC/inert gas mixture and absorb further VOC. The remainder of the rich kerosene leaving the absorption column 12 passes to a buffer tank 34 where it is held. It is then pumped to an elevated pressure distillation (stripper) column 46, where VOC is separated from the kerosene by conventional rectification. VOC vapor leaving the top of the distillation column is condensed in condenser 72 and held in the VOC reflux tank 76. Liquid VOC from the reflux tank is passed to a crude oil pipeline 82; a portion of the liquid VOC from the reflux tank enters the top of the distillation column to act as reflux. Kerosene leaves the bottom of the distillation column 46 and passes to a storage tank 60 where it is held. From there, it passes through a cooler 66 to the absorption column, to absorb further VOC from incoming VOC/inert gas mixture. The coolers for this lean kerosene and for the rich kerosene which re-enters the absorption column are preferably cooled by the same refrigeration system 68. The buffer and storage tanks are size that the elevated pressure distillation column can run continuously.