Flare Gas Recovery – Flare gas recovery (or zero flaring) is a strategy evolving from the need to improve environmental performance. Conventional flaring practice has been to operate at some flow greater than the manufacturer’s minimum flow rate to avoid damage to the flare (Miles, 2001).
Flare Gas Recovery in Plants & Refineries | Energy Conservation
Typically, flared gas consists of background flaring (including planned intermittent and planned continuous flaring) and upset blow down flaring. In offshore flaring, background flaring can be as much as 50% of all flared gases. In refineries, background flaring will generally be less than 50%, depending on practices in the individual refinery.
Recent discussions on emissions from flaring by refineries have highlighted the issue from an environmental perspective. The findings highlighted the higher emissions compared to previous assumptions of the Air Quality District, due to larger volumes of flared gases. Reduction of flaring will not only result in reduced air pollutant emissions, but also in increased energy efficiency replacing fuels, as well as less negative publicity around flaring.
Emissions can be further reduced by improved process control equipment and new flaring technology. Development of gas-recovery systems, development of new ignition systems with low-pilot-gas consumption, or elimination of pilots altogether with the use of new ballistic ignition systems can reduce the amount of flared gas considerably. Development and demonstration of new ignition systems without a pilot may result in increased energy efficiency and reduced emissions.
Reduction of flaring can be achieved by improved recovery systems, including installing recovery compressors and collection and storage tanks. This technology is commercially available. Various refineries now even the small ones have installed flare gas recovery systems. Any plant-wide assessment now of any old refinery highlights the potential for flare gas recovery.
In recent new project refinery design, flare gas recovery systems has reduced flaring to near zero levels. The refinery will only use the flares in emergencies where the total amount of gas will exceed the capacity of the recovery unit. The recovered gas is compressed and used in the refinery fuel system. Furthermore, flare gas recovery system offers increased flare tip life and emission reductions.