Patent ID: 8277565

Claim:
A method for removing hazardous materials from vapour in a tank, the hazardous materials having a melting point and a self ignition point, wherein at an initial temperature, the vapour comprising hazardous materials, present in the tank, is heated by a heating means, the vapour thus formed is passed outside the tank by means of a pump through a cooler, wherein the vapour is cooled, liquefied components of the vapour comprising said hazardous materials are isolated and removed, and remaining dry vapour is recirculated to the tank, recirculating being continued until a desired level of hazardous material has been removed, characterized in that the vapour comprising hazardous material is heated in the tank to a temperature of at least 5° C. above the melting point and below the self ignition point of the hazardous material to be removed, the vapour is cooled in the cooler to a temperature of at least 5° C. lower than the initial temperature and above the melting point of the hazardous material and the remaining dry vapour comprising hazardous material is reheated in the tank to a temperature of at least 5° C. above the melting point and below the self ignition point of the hazardous material.