CalEPA formed an Interagency Refinery Task Force (IRTF) on refinery safety with membership that includes ten state agencies, U.S. EPA, and local agencies from areas of the state that contain refineries. They are working to achieve the highest level of safety for refinery workers and local communities, and to prepare for and effectively respond to emergencies if they occur.
What is a Flare?
A Flare is a tall stack equipped with a burner, used to process any excess gases produced by refinery including sub-processes such as the sulfur recovery plant and tank farm. The Flare system is in operation all of the the time. Most of the time the Flare system is in standby mode, ready to combust gases as soon as they enter the Flare.
How do the Flares work?
Oil refining is a dynamic process. Temperatures, pressures and other processing conditions are carefully controlled to maintain steady-state production operations. When operating conditions in a refinery cause the pressure in the plant to rise, valves automatically open to divert gases to the Flare.
What does flaring look like?
A pilot flame must be lit whenever the Flare is in operation so that purge gases (used to keep air out of the flare) and vent gases can be readily combusted. The pilot flame is located at the tip of the Flare. When vent gases are combusted in a Flare, a larger flame is sometimes visible at the Flare tip. Sometimes steam, which is used to help burn the vent gases completely, is also seen at the Flare tip. Sometimes during a flare event when steam cannot be added to the system quickly enough, or if the smokeless capacity of the Flare is exceeded, smoke may also be visible at the edge of the flame.
What is the difference between smoke and steam?
Smoke is combustion-generated particulate matter which becomes entrained in air; the smaller the particle, the longer it is likely to remain suspended in air. Suspended particulates obscure visibility by refracting (bending) and scattering light. Measuring the density of these particles against a reference standard provides an indication of relative opacity. Whenever smoke is generated during a flaring event, it appears immediately downstream of the flame.
Steam is condensed water vapor that is added to the Flare to increase turbulence, thereby improving combustion of vent gases and reducing the potential for smoking.
What kinds of emissions are vented from the Flare?
Flare emissions can include water, carbon dioxide, oxides of sulfur (SOx), oxides of nitrogen (NOx), particulate matter (PM10), carbon monoxide (CO), and reactive organic gases (ROG) including Volatile Organic Compounds (VOC).
Under what circumstances does flaring occur?
During an emergency caused by an equipment breakdown, power outage or other upset beyond a refinery's control, the Flare is used to safely burn gases that could otherwise pose potential risks to workers, the community or the environment. The Flare is also used to ensure safety during the startup and shutdown of refinery equipment when gases generated by those processes cannot be safely recycled into the refinery.