Dominant and dramatic as flares are in the landscape of communities near oil refineries, for residents they symbolize the sources of health-threatening air pollution from refineries. Residents in these neighborhoods have further suspected the flares have been used, not only as safety devices, but also for routine disposal of gases that could be collected and reused. The current actions of the Bay Area Air Quality Management District (Air District) to regulate the use of refinery flares have been particularly welcome in these communities.
A flare is a safety device that burns off gases vented from refinery process units. The gases from the process units are collected for use as fuel at the refinery, with any excess vented to flares. An alternative would be to vent the excess gas directly into the atmosphere. Excess gases are produced during startups and shutdowns of process units and equipment, as well as during emergency or upset conditions. Flares range in size, but most are tall—about twenty feet high and about four feet in diameter—and all are noisy when in operation.
In preparing the Bay Area 2001 Ozone Attainment Plan, air quality planners identified several measures that showed promise for reducing emissions of ozone precursors, but could not be developed within the time frame of the Plan. These Future Study Measures (FSMs) in the Plan included FSM-8: Refinery Pressure Vessels, Blowdown Systems, and Flares.
As the Air District staff began investigating the available information on the Bay Area's refinery flares, the lack of sufficient data to use as a basis for developing regulations became apparent. To gather needed information, Regulation 12, Rule 11: Flare Monitoring at Petroleum Refineries was adopted by the Air District Board of Directors in June 2003 (see August/September 2003 issue). Under this rule, each refinery prepares monthly reports sent to the Air District. The reports must contain detailed information of each flaring event of 15 minutes or longer. The amount and composition of the gases vented to each flare must be recorded, using specified monitoring and analyzing equipment and procedures. Flare activity is recorded with video cameras. Using the information in these reports, the Air District staff prepared the draft Regulation 12, Rule 12: Flares at Petroleum Refineries.
The Bay Area is home to five oil refineries, four in Contra Costa County and one in Solano County. The five refineries have a total of 23 flares currently subject to the flare monitoring rule. In evaluating the monitoring data gathered under Regulation 12, Rule 11, the Air District staff found that each refinery is unique in its operations, each with its own list of products that it manufactures. The staff also found that the attention focused on flares during development of Rule 11 caused the refineries to scrutinize flare operation of flares and flare-associated equipment, to reduce the number of flaring events, and to take measures to reduce emissions from the processes associated with flares. All in all, emissions from flares were significantly reduced; the current estimate, on an annualized average basis, is now 2 tons per day for total (methane and non-methane) hydrocarbons.
The goal of the proposed Rule 12 is to assure that the emissions reductions that have been achieved since Rule 11 was adopted are maintained, and to further reduce flare emissions. The draft rule proposes prohibiting routine flaring, except for safety reasons or when the gas, because of its quantity or quality, cannot be recovered for use as fuel. The draft rule would also require refineries to prepare a Flare Management Plan (FMP) for each of their flares.
A FMP would be expected to contain a detailed description and technical information for the flare and all equipment and processes that vent to the flare, including an accurate flow chart and dimensions and capacities of vapor recovery systems. Monitoring and control equipment would be fully and accurately described. Any equipment, process, or procedure that the refinery has installed or implemented in the past to reduce flaring would be described. Similarly, such equipment, process, or procedure planned for the future would also be described.
Flaring that has occurred in the past or is expected to occur during planned major maintenance, including startup and shutdown, would be described and evaluated to determine the feasibility of performing these activities without flaring. Flaring that may occur because of the quality or quantity of gas released would be described and evaluated to determine the feasibility of recovering and treating the gases for use as fuel or for other purposes, thus avoiding flaring.
A procedure for eliminating avoidable flaring events caused by recurring equipment breakdown would be required. A process for identifying additional equipment, processes, and procedures to reduce flare use would also be required. Implementation schedules for capital improvements and for measures to prevent flaring would be prepared.
The rule also contains time schedules for the preparation and submission of FMPs to the Air District, the review and approval of the FMPs by the Air Pollution Control Officer, the updating of the FMPs, and annual reports on the flaring of gases flowing at a lower rate than would be designated as a flaring event (less than one million standard cubic feet per day).
In March, the Air District held two public workshops in Martinez and Richmond to take comments on the draft rule. The draft Regulation 12, Rule 12 may be found on the Air District website and comments can be made by e-mail, phone, or mail.
Adelia Sabiston
For more information:
Alex Ezersky, Principal Air Quality Specialist, BAAQMD, 415-749-4650; aezersky@baaqmd.gov
The draft of Rule 12 is online at http://www.baaqmd.gov/pln/ruledev/12-12/1212_dr_0215.pdf
Flare monitoring reports are online at http://www.baaqmd.gov/enf/flares