There is disclosed a method for the removal and recovery of hydrocarbons which are contained within the air/vapor mixture in bulk oil or gasoline storage tanks using fractional condensation with cryogenic cooling. The air/vapor mixture is flushed from the tank with fresh air and passed, successively,...http://www.google.com/patents/US5144807?utm_source=gb-gplus-sharePatent US5144807 - Vapor treatment facilities for petroleum storage tank cleaning
