Flaring is the practice of burning flammable gases and vapors, (and sometimes liquids), in order to convert them to the, relatively innocuous, products of combustion – carbon dioxide and water – in preference to discharging them in a potentially harmful, untreated manner into the environment, in circumstances when they must be treated as waste Flaring is most commonly seen within Oil Refineries and on Oil Production Platforms, where elevated flares are present as tall, chimney-like structures with visible flames at the top.

What is Flaring?

Flaring is the practice of burning flammable gases and vapors, (and sometimes
liquids), in order to convert them to the, relatively innocuous, products of
combustion – carbon dioxide and water – in preference to discharging them in
a potentially harmful, untreated manner into the environment, in circumstances
when they must be treated as waste Flaring is most commonly seen within Oil
Refineries and on Oil Production Platforms, where elevated flares are present
as tall, chimney-like structures with visible flames at the top.

Why is Flaring Necessary?

Typically, Petroleum and Chemical plants are made up of many independent but
inter-dependent processes operating in a fine balance. In day-to-day operations,
slight operational imbalances between the processes sometimes cause the production
of excess product which cannot be safely handled by the equipment without creating
a dangerous over-pressure. Relieving this excess to a flare allows the plant
to continue to function regularly and safely without danger of explosion, and
avoids the possibility of relieving hazardous chemicals directly into the environment.
In the extreme case of a major upset, discharging the contents of a plant rapidly
to a flare allows operators to avert danger of fire or explosion.

Who Uses Flares?

Flares are used by many industries and for many applications in which handling
of flammable gases is involved.
Typical applications include :

  • Oil and Gas Production Wells, Oil and Gas Pipeline Pumping Stations, Oil Refining,
    Petrochemical Processing, Pharmaceutical , Manufacture, Storage Tank Farms,
    Tanker , loading and unloading
  • [Marine, Rail and Road], Steel making Plants, Coal and Wood Gasifiers Landfill
    Venting, Sewage Treatment Plants

Do Flares Waste Energy?

There can, indeed, be a lot of energy wasted when materials are flared. A
really large flare can be designed to relieve much more than 1 million pounds
per hour of hydrocarbon which releases about 6,000 kW of energy and is on the
scale of a small power station.

Looking at this in context however, we must remember that this usually represents
the entire inventory of the plant being relieved in an emergency, that it only
runs at this rate for about 5 to 10 minutes and, probably, never actually occurs
at all. When plants actually have an ‘excursion’ leading to a minor emergency
relief, it is more likely to be in the range of 20,000 to 100,000 pounds per
hour [100 – 500 kW] and will only last for 5 minutes or so.
For almost all their operating lifetime, most flares will operate with little
to zero flow, being simply on standby to guard against the emergency event.

Are there other uses for Flared Gases?

Almost all responsible operators attempt to minimize the amount of relief
to the plant Flare and many also utilize equipment which can recover relieved
gases before they reach the Flare, in order to recycle them through the plant
for efficient use.
In a few cases however, some of the materials are not able to be re-processed
and, in these cases plants attempt to recover them for use as fuels either to
operate the processes themselves or to generate alternative energy forms, such
as steam or
electricity, in a manner known as co-generation.
When the amounts of relieved gases exceed the re-processing or re-use capacity,
or become otherwise unmanageable, they must be sent to the flare.
The most severe cases of long term gas flaring occur in the oil producing fields
where there is no immediately available use for the gases which escape from
the oil as it is pumped from underground wells.