Recent published data suggests that flaring equipment used in the oil and gas (O&G) industry may have an average destruction and removal efficiency (DRE) in the range of 91 to 92%, which is lower than the standard accepted default DRE of 98%. The lower DRE can be caused by venting from unlit flaring systems.
Unlit flares are an invisible enemy of effective emission control for oil and gas (O&G) operations because they vent VOCs and methane into the atmosphere.
Flaring is widely used to control natural gas released from O&G industry operations. Natural gas is flared at O&G facilities and pipelines for operational, safety and environmental regulatory reasons. Devices used for flaring gas include open-tipped, candlestick flares and enclosed combustion devices (ECD). These devices should combust the gas stream on a consistent basis and at the highest possible DRE.
When flares are properly designed, operated and monitored, they can maximize DRE and minimize venting from an unlit flare. This is especially true for air-assisted flares that can consistently achieve a 99%+ DRE and ECDs that achieve a 98%+ DRE.
Regulatory Required Monitoring of Flaring
Federal New Source Performance Standards OOOO/OOOOa and state air permits and regulations require combustion control devices to operate a reliable, continuous pilot flame. The following steps are used to ensure combustion when gas is sent to the flare/ECD.
- Install and operate a continuous burning pilot flame.
- Heat sensing monitoring devices that indicate the continuous ignition of the pilot flame.
- Continuous recording device that indicates the continuous ignition of the pilot flame.
- Alerts to operators to take corrective actions when the pilot flame is not lit.
Compliance considerations are important when optimizing a flare for maximum control of the natural gas stream. The DRE of flares is used to calculate emissions for air permits, NSPS OOOO/OOOOa compliance, state annual emission inventories and annual greenhouse gas (GHG) reporting rules. Starting in 2024, the federal government will assess a methane emissions charge for excess methane emissions from O&G facilities. A consistently high DRE flare or ECD is key to minimizing methane fees due to the future methane charge.
The use of optical gas imaging (OGI) cameras and satellite monitoring for methane emissions from O&G operations increases the likelihood that venting from unlit flares and low DRE flares are detected and reported. This is especially true for super emitters of methane. The USEPA’s proposed rule in 40 CFR 60 Subpart OOOOb would define a super emitter as emitting 100 kg of methane per hour.
Flaring Removal and Destruction Efficiency (DRE)
According to the USEPA emission factors guidance in AP-42, Section 13.5 Industrial Flares, flares combusting hydrocarbons have an estimated destruction efficiency of 98%.This is the typical, default value used for emission calculations for air permits and reporting of GHG emissions to the USEPA e-GGRT system.
Recent studies and reports indicate that the typical open-tipped flare has a DRE less than 98%.
A September 2022 report from the International Energy Agency (IEA) estimated for worldwide flaring of natural gas the DRE was approximately 92%.
A September 2022 article in Science addressed the destruction efficiency of natural gas flaring in the U.S. The authors estimated that the combination of unlit flares and inefficient combustion by flares resulted in a destruction efficiency of 91.1% for methane with a 95% confidence interval of 90.2% to 91.8%.
Solution to Reduce Frequency of Unlit Flares
- Monitor pilot flames continuously to ensure a flame is present.
Pilot flames can be monitored using the following Cimarron systems:
- For ECDs, use Cimarron’s ARC™ Burner Management System to ensure the pilot flame is lit.
- For typical candlestick pipe flares, use Cimarron’s Sytelink360™ to continuously detect the presence of a pilot flame.
- If pilot flame (ECD, flare) is not lit, then send an automated alert to field operations.
Cimarron’s Sytelink360™ system can handle continuous pilot flame monitoring and alerts to field operations. Also, the system can track, store and report hours that a pilot flame was present for the ECD and flare system.
- Avoid over-aeration of air assisted flares.
For air-assisted flares, use Cimarron’s DRE-Max™ as a smart control system. DRE-Max™ is an innovative device that implements a sophisticated algorithm using field data to manage air assisted flares to achieve 99%+ DRE and minimize smoking. Combine the DRE-Max™ with continuous monitoring and alerts for the pilot flame and a facility can maximize the DRE along with greater uptime for a continuous combustion of gas at the flare tip.
- Take corrective actions to fix the issue and conduct a root cause analysis to determine the cause and corrective actions to fix the issue and actions to prevent recurrence.
Summary and Conclusions
Flaring equipment used in the oil and gas industry may have an average destruction and removal efficiency (DRE) in the range of 91 to 92%, which is lower than the standard accepted default DRE of 98%. The lower DRE can be caused by venting from unlit flaring systems. Unlit flares are an invisible enemy of effective emission control for oil and gas (O&G) operations because they vent VOCs and methane into the atmosphere.
Regulatory required monitoring of flaring require combustion control devices to operate a reliable, continuous pilot flame. To achieve this, devices used for flaring gas should combust the gas stream on a consistent basis and at the highest possible DRE. When flares are properly designed, operated and monitored, they can maximize DRE and minimize venting from an unlit flare. This is especially true for air-assisted flares that can consistently achieve a 99%+ DRE and ECDs that achieve a 98%+ DRE.
Cimarron Solutions provides services to help clients optimize their flare systems. These include flare system design, installation, commissioning, testing, maintenance and repair. With over 30 years of experience in the industry, Cimarron Solutions has the expertise to help clients achieve maximum control of their natural gas stream while minimizing emissions.
Cimarron – Who We Are
Cimarron’s vision is to work with our clients to create a cleaner environment. The company engineers and manufactures environmental, production and process equipment for the upstream, midstream and downstream energy industries, as well as environmental control solutions for biogas at wastewater facilities, digester tanks and landfills. Our flares and ECDs meet all federal and state environmental regulatory requirements for control efficiency and destruction efficiency.
Cimarron offers our customers the know-how and environmental expertise to meet the environmental standards of today and tomorrow. Cimarron is committed to bring value to the Energy industry and their shareholders based on our financial strength, experienced personnel, and engineering capabilities.
As a company, we thrive every day to make a difference through innovation (e.g. ESG), customer focus, and operational efficiency. In addition to being present in all major regions in the US, Cimarron serves more than 45 countries around the world, ranging from offshore to desert. From key operational centers in the United States, Italy and the United Arab Emirates, Cimarron offers ongoing service and support through its own field service personnel and strategic third-party partners, creating a cleaner environment for our customers and their shareholders.
Since its founding in the mid-1970’s in Oklahoma, the company’s product offering has expanded from production equipment to include the largest line of environmental solutions that capture or incinerate fugitive vapors. With the acquisitions of HY-BON/EDI in 2019 and AEREON (including Jordan Technologies) in 2020, Cimarron has added strong brands, products, and services to its portfolio.
Please contact us to learn more about our products and services and about all our ESG solutions at firstname.lastname@example.org or visit our website www.cimarron.com.