Patent ID: 6478849
Filing Date: 2002-11-12
Classification: B01D,B67D,F02M

Abstract:
A method for recovering vapors from a fuel storage tank having a ullage including VOC vapors and non-VOC vapors, comprising:monitoring the pressure in the fuel storage tank ullage; withdrawing vapors from the fuel storage tank ullage; feeding the vapors through a first canister including a VOC adsorbing material and permitting non-VOC vapors to exit the first canister; and exhausting substantially all non-VOC vapors from the first canister to the atmosphere; and if the VOC adsorbent material of the first canister becomes saturated, feeding the vapors through a second canister including a VOC adsorbing material and permitting non-VOC vapors to exit the second canister; exhausting substantially all of the non-VOC vapors from the second canister to the atmosphere; regenerating the saturated VOC adsorbent material of the first canister by evacuating the VOC vapors from the saturated VOC adsorbent material of the first canister into the fuel storage tank ullage; and determining if the VOC adsorbing material of the first canister is saturated with VOC vapors by monitoring the concentration of VOC vapors.