Measurement: vapour recovery: How is recovered vapour measured?
Manufacturers make various claims for the efficiency of their systems but the huge throughput of a refinery can make the systems a cost-effective investment despite the fact that they have to be present by law.
A rough estimate of the amount of motor spirit expected to be recovered is one litre per 1,000 litres loaded, and for a 1,000 litres of distillates the recovery of liquid is about a quarter to a third of a litre.
Because the amounts recovered are small and many units work by adding the vapour back into a stream of product, it is often not considered possible or practicable to measure the recovered fuel with meters. Accordingly we have a complex formula to work out the amount of duty that can be reclaimed. Vapour recovery claims and this formula are under review by the Oils Team (Policy). The current formula is said by one oil firm to result in errors costing it £580,000 a year - but this is for all its operations and before vapour recovery, vapour was merely lost to the air. Claims only began in 1999.