Many service stations in the world today are equipped with:

Stage I Vapour Recovery System in which the vapours from the underground tanks of the service station are balanced back to the tank truck and the vapours in the truck are recovered by a Vapour Recovery Unit at the Storage Terminal.

Stage II, the recovery of the vapours from filling of the cars, back to the underground tank of the service station is not as widely implemented. Stage II returns the vapours from the car tanks back to the underground tank by means of a controlled vacuum system, whereby an amount of vapours, equivalent of the loaded liquid, is sucked from the opening of the car tank and pumped back to the underground tank. Stage II will evidently reduce the emissions of hydrocarbon vapours to the atmosphere during filling of cars and will as such increase the concentration of the hydrocarbon vapours present on top of the liquid product in the underground tanks.

In cases where the vapours from the underground tanks at the service stations cannot or not economically be returned to the truck tank during filling of the underground tank, a dedicated small recovery system (MINIVAC) can be installed at the service station to recover the vapours during filling of the underground tank as well as any excessive vapours from incomplete balancing between car and underground tank. Most balancing systems are not able to achieve better recovery efficiencies than 65 to 70% from the car tank.

CADABCO introduces a new, simple and innovative Vapour Recovery System (MINIVAC) to the market based on adsorption on activated carbon and regeneration by vacuum. The recovered hydrocarbon components are re-injected into one of the gasoline grades in the underground tank system. This Recovery System is able to reduce the emissions from the service station operations better than 99%.

Recovered Product Calculation

The CADABCO MINIVAC Vapour Recovery Unit will recover at least 99% of the emitted vapours.

The amount of liquid product recovered from one single truck emptying operation will therefore be around = 56 Ltrs of liquid product. This product is returned to the underground tank.