At the 2020 4C Health, Safety & Environment conference, Emerson’s Jamie Marsden presented, New Refinery Flare Regulations 40 CFR Part 63. The rule, 40 CFR 63 Subparts CC and UUU, affects any refinery with a flare used as a control device for an emission point, and those refineries must have been in compliance by January 30, 2019.
These regulations set flare operating limits, require a flare management plan (FMP), and require a continuous parameter monitoring system (CPMS) plan. The regulations also cover pilot flame monitoring, visible emissions and flare tip velocity—requirements previously found in earlier versions of the rule.
Jamie explained that the FMP rule specifically states:
For each flare, the owner or operator shall operate the flare to maintain the net heating value of flare combustion zone gas (NHVcz) at or above 270 British thermal units per standard cubic feet (Btu/scf) determined on a 15-minute block period basis when regulated material is routed to the flare for at least 15 minutes.
For each flare actively receiving perimeter assist air, the owner or operator shall operate the flare to maintain the net heating value dilution parameter (NHVdil) at or above 22 British thermal units per square foot (Btu/ft2) determined on a 15-minute block period basis when regulated material is being routed to the flare for at least 15 minutes.
It allows the (EPA) Administrator to confirm that the selected site-specific operating limit(s) adequately ensures that the flare destruction efficiency is 98 percent or greater or that the flare combustion efficiency is 96.5 percent or greater at all times. Combustion efficiency, net heating value in the combustion zone, and net heating value dilution parameter are calculated as defined in rule CFR 63.670.
The gas chromatograph performing these measurements average continuous emissions monitoring system (CEMS) calibration response must not differ by more than 10 percent of calibration gas value at each level after each 24-hour period. Any one injection shall not deviate more than 5 percent from the average concentration measured at that level. The linear regression curve for each organic compound shall have an r 2 ≥0.995.
The sample to be analyzed shall flow continuously through the sampling system. The sampling system time constant shall be ≤5 minutes or the sampling frequency specified in the applicable regulation, whichever is less.
Here’s a typical flare system to meet the 40 CFR 63.670 controls:
Jamie shared the basics of a gas chromatograph system:
There are two standard Rosemount gas chromatograph solutions to meet the flare vent gas composition monitoring requirement of 40 CFR Part 36. The first solution, a Rosemount 1500XA process gas chromatograph measures hydrocarbons, H2S, H2, CO and CO2. The second 1500XA option measures hydrocarbons, H2S, H2, CO, CO2 and Benzene.
Jamie also noted that custom solutions are also available since the downstream hydrocarbon producer is responsible for confirming the components that are in the flare that need to be measured.
Visit the Gas Chromatography for Environmental Monitoring section on Emerson.com for more on solutions to comply with flare regulatory reporting. You can also connect and interact with other gas chromatograph experts in the Measurement Instrumentation group in the Emerson Exchange 365 community.