New EU regulation on methane emissions:
What are the available gas leak detection technologies to comply with?
A key part of the EU Methane Strategy, the first-ever EU regulation on reducing methane emissions in the energy sector (EU/2024/1787) took effect on August 4, 2024. The regulation mandates the implementation of Leak Detection and Repair (LDAR) programs across all oil and gas facilities in the European Union. There are various technologies available to perform LDAR programs such as Acoustic Leak Imaging (ALI) cameras (ultrasonic cameras), Optical Gas Imaging (OGI) cameras, and Flame Ionisation Detectors (FID).
A comparison of the Distran ultrasonic camera with a combination of an FID and an OGI camera showed: The ultrasonic camera required only 20% of the inspection time to detect the gas leaks accounting for 80% of the methane emissions.The Oil and Gas Industry is a significant contributor to greenhouse gas emissions, mainly through methane (CH4) emissions from its operations. Reducing those emissions is hence highly relevant for the fight against climate change. Methane’s impact on climate change:the Global Warming Potential of methane is 84 times higher than CO2 over a 20-year period.
LDAR as a key strategy to help reduce methane emissions
Designed to identify and address fugitive emissions and gas leaks effectively and promptly, leak detection and repair programs (LDAR) in the energy sector come off as one of the key strategies for reducing methane emissions and their impact on the environment, human safety, and financial costs.
The IEA indicates that implementing LDAR programs could prevent the emission of around 17.2 megatons of methane, or 514.79 megatons of carbon dioxide equivalents, from which 65% (or 11.2 megatons CH4) could be achieved at no net cost. This translates to a promising saving potential of 618 kilotons of methane at the European level.
LDAR programs could prevent the emission of 618 kilotons of methane in Europe per year.
Few member states of the European Union(EU) have issued national rules to mandateLDAR programs. However, they intend to make considerable progress towards meeting methane reduction objectives by fostering a regulatory framework at the European level. As part of the EU methane strategy, the European Commission adopted a regulation on methane emissions reduction in the energy sector on August 4th 2024.
The regulation defines obligations to detect and repair methane leaks from all installations in the Oil and Gas Industry. To this extent, companies must submit LDAR programs to national authorities six months after the regulation comes into force. The regulation defines two levels of inspections for methane emissions: Type 1 and Type 2.
Operators must repair or replace all aboveground components emitting methane at or above specified thresholds:
• Type 1 LDAR Surveys: Components emitting 7,000 ppm or 17 grams/hour of methane.
• Type 2 LDAR Surveys: Components emitting 500 ppm or 1 gram/hour.
Frequency of LDAR surveys depends on the type of facility to be inspected and is defined in the Annex I of the regulation.
Repairs must be conducted immediately after detection. If immediate repair is not possible, it must be attempted within 5 days and completed within 30 days. Operators should prioritize fixing larger leaks and ensure minimal environmental impact while addressing safety and technical considerations. Besides the minimum detection limit, the planned regulation stipulates no other requirement regarding gas leak detection technologies. Organisations in the energy sector will probably be free to choose which technology best fits their needs
Different technologies to detect methane leaks
There are two main categories of methane leak detectors:
- Remote sensors including infrared-based methods such as ultrasonic cameras based on Acoustic Leak Imaging (ALI), and Optical Gas Imaging (OGI) cameras.
- Direct contact sensors such as Flame Ionization Detectors (FID), Photoionization Detectors (PID), catalytic bead sensors, etc.
Ultrasonic cameras (remote sensors)
Ultrasonic cameras that harness Acoustic Leak Imaging (ALI) combine an array of ultrasound- sensitive microphones and an optical camera. They take advantage of the fact that gas leaks generate ultrasounds due to the pressure difference between the pressurized system and the environment.
Every microphone receives the ultrasonic waves at a different time, and acoustic imaging algorithms combine the temporal signals of the microphones to obtain an image. This acoustic image is overlaid in real-time onto the optical image, indicating precisely the location of the leak. Provided there is a minimum pressure difference of a few millibars, some models of ultrasonic cameras can allow for the detection of small leaks (for example 0.3L/h
of methane). Ultrasonic cameras allow for the detection of leaks of any pressurized gas at a distance, independently from the environmental conditions (wind, temperature etc.).They simplify the inspection of large areas in little time and some of them provide real-time quantification of leak rates on the device‘s screen.
- Sensitivity – High
- Ease of use – High
- Time requirement – Low
- Detection at a distance – Yes
- Real-time quantification – Yes
OGI cameras (remote sensors)
OGI cameras are a special type of infrared camera. The detection of leaks with such a device relies on
the visualisation of the absorption of gases in the infrared domain. These cameras are specifically tuned
to detect methane and other hydrocarbon gases, as these gases absorb enough infrared light in the spectral domain where the OGI sensors are sensitive (depending on the device, typically between 2 to 8 μm wavelength). This absorption is detected from the contrast between the background radiation and
the gas plume, making the gas plume visible for the operator. OGI cameras are usually able to detect gas concentrations above 5,000 to 10,000 ppm in industrial conditions. However, weather conditions can significantly impact their capacity to detect leaks by altering the visualization of the plume. In this case, the interpretation of the images can be tedious and highly depends on the user experience.
- Sensitivity – High (hydrocarbon gases)
- Ease of use Time requirement – Low
- Detection at a distance – Low
- Real-time quantification No
FIDs (direct contact sensors)
Among the numerous kinds of direct contact detectors for detecting fugitive emissions, Flame Ionization Detectors (FIDs) are the most common devices in the gas industry. They estimate the concentration of the target gas by measuring the charge (or number of ions) produced by the ionisation of a sample of
the atmosphere with a hydrogen-air flame. FIDs feature a high sensitivity to hydrocarbon gases such as methane, meaning they can detect small concentrations of gas (<1 ppm) in the atmosphere and hence small leaks. However, employing FIDs for surveys can be tedious and labor-intensive, requiring the inspection of each potentially leaky component through direct contact. Moreover, as FIDs detect a gas concentration, the presence of a significant nearby leak with a high concentration can mask smaller leaks that might go unnoticed. The accuracy of the detection and the measurements can thus vary based on the operator‘s experience.
- Sensitivity – High (hydrocarbon gases)
- Ease of use – Medium
- Time requirement -High
- Detection at a distance – No
- Real-time quantification – Yes
In short, various technologies are available to detect methane leaks. The specific challenges an industrial site faces are crucial to determine which is the best-fitting technology. With regard to the planned EU regulation on methane emissions, all three technologies explained above meet at least one of the two stipulated LDAR criteria. Both Optical Gas Imaging (OGI) and Acoustic Leak Imaging (ALI) satisfy the Type 1 requirement, while the sniffer technology fulfills both Type 1 and Type 2 requirements. Differing considerably in various regards, they all may contribute to reducing methane emissions and counteract climate change.
Inspection time
The simultaneous use of the OGI + FID devices resulted in an inspection time of 2.5 days. It is to be noted that an OGI-only inspection would have been faster, but fewer leaks would have been found due to the lower sensitivity (5,000 to 10,000 ppm, see above ). On the other hand, the inspection of the same area with the Distran ultrasonic camera took 4 hours, 20% of the time the combined technologies needed for the same inspection.
Inspection duration: OGI + FID: 2.5 days Ultrasonic camera: 0.5 days.
Detected leaks & measured emissions
Both approaches, ALI on one hand and OGI + FID on the other, resulted in some missed leaks. Notably, those which ALI failed to detect were associated with lower emissions compared to those missed by the OGI + FID. In other words: the ultrasonic camera managed to detect emissions equivalent to the emissions detected by OGI + FID – within just 20% of the inspection time. Although this study is based on a reduced sample size, the results appear to be representative of the leak count and emissions at larger gas stations. Indeed, studies carried out on a larger scale, have led to similar findings, acknowledging that a limited number of significant leaks contribute to most of the total emission.
Compliance of the studied technologies with the new EU regulation
As stated above, the new EU regulation introduced two different inspection levels with different limits of detection and varying inspection frequencies which would require different inspection devices.
The first level of detection aims to target the largest leaks in terms of emissions, defined by a leak rate above 17g/h. In this study, 3 leaks exceeding this threshold were reported, all successfully detected by the ultrasonic camera, while one remained undetected by the other approach. The inability of the OGI + FID to detect this significant leak can be attributed to a potential oversight by the operator. While both devices had the capacity to detect the leak,
it could have easily gone unnoticed due to human error during the inspection. This contrasts with the ALI device, which eliminates the need for image interpretation. The precise location of the leak source is explicitly and clearly indicated on the camera’s screen, making any such oversight highly unlikely.
Conclusions
The European Union recognised the importance of addressing methane emissions from the Oil and Gas Industry by adopting a regulation for the mandatory implementation of LDAR programs.
According to the presented study, inspecting facilities similar to the one surveyed would result in the detection of an equivalent amount of methane emissions, whether utilizing the Distran ultrasonic camera or employing OGI + FID.
Nevertheless, only the ultrasound camera detected 100% of the type 1 leaks (all leaks with a rate exceeding 17 g/h). In addition, the use of the ultrasonic camera is expected to enable significantly faster inspection times, up to 5 times faster compared to an equivalent survey using OGI + FID.
