HFC detection using optical gas imaging increases safety/efficiency while reducing emissions

C. O’Neill, Teledyne FLIR, Dallas, Texas; and R. A. Chochran, Contributor, Parkersburg, West Virginia

The use of optical gas imaging (OGI) cameras has benefited the oil and gas industry greatly by improving worker safety and plant efficiency while reducing emissions; however, the technology has yet to gain a similar foothold in the petrochemical industry, despite offering similar advantages. Comfort with existing gas-detection methods and a lack of familiarity with the full capabilities of OGI cameras often act as barriers to implementation. However, with commercial hydrofluorocarbon (HFC) gas emissions now under increased scrutiny by governments and regulators around the globe, there is increased impetus for HFC producers and industrial HFC users to deploy new and emerging technologies to ensure the mechanical integrity of their processes and equipment.

Many well-prepared companies already have environmental, social and governance (ESG) programs driving sustainability, including initiatives tied to emissions reduction. Still, the continued use of ambient air monitoring utilizing Fourier transform infrared (FTIR) spectroscopy, supplemented by handheld leak detectors, is only a partial solution to the need for more comprehensive industrial monitoring, especially as regulators begin to employ state-of-the-art instrumentation.

This incumbent system of leak detection has several constraints that must be understood by industrial practitioners. On-demand point leak detection generally takes place either during routine maintenance or when a FTIR ambient monitor alarm is triggered by a possible gas leak. A production operator with appropriate personal protective equipment (PPE) must then be positioned close to the leak source to confirm its existence by using a handheld refrigerant leak detector (referred to as a toxic vapor analyzer, organic vapor analyzer, or “sniffer”).

A handheld vapor analyzer may be unable to accurately identify the leaking component—this is key when repairing or understanding the challenges associated with a leak (FIG. 1). The emissions source may also be in a difficult-to-access location, making leak confirmation with a handheld detector difficult or even impossible.

OGI cameras can detect leaks from a safe distance and can identify leaks in locations or volumes that otherwise would not be discovered. These cameras supply visible confirmation of emissions—whereas, a vapor analyzer’s readings can vary from one minute to the next, depending on environmental conditions, even when sampling in the exact same location. Meeting the industry’s demand for more precise and safer refrigerant leak detection, the co-author’s company offers OGI cameras that satisfy a range of use scenarios, from pinpointing difficult-to-find leaks to identifying different gases with a single device.

The co-author’s company’s proprietary OGI camera^a is the industry’s only cooled OGI camera filtered specifically to detect fluorocarbons. In addition to visualizing refrigerant leaks precisely from a distance, this proprietary OGI camera^a can accurately measure temperatures, allowing users to note temperature differentials and improve visual contrast for better gas plume detection (FIG. 2A).

Another proprietary OGI camera^b detects hydrocarbon and volatile organic compound (VOC) emissions from natural gas production and use. With this OGI camera, inspectors can check thousands of components and see potential gas leaks in real time. This camera is lightweight, offers both a viewfinder and LCD monitor, and has direct access to controls. Embedded GPS data helps in identifying the precise location of faults and leaks for faster repairs.

A third proprietary OGI camera^c is an uncooled OGI camera with interchangeable lens options capable of detecting fluorocarbons, methane, sulfur hexafluoride and other gas emissions. While not as precise as the HFC-focused proprietary OGI camera^a, this technology offers lower-cost utility to users hunting different types of gas leaks (FIG. 2B).

Case study: Petrochemical company adopts OGI technology for detection. Chemours—a global manufacturer of advanced materials for critical applications—was introduced to OGI technology by a European third party that provides on-demand site surveys using the technology. In 2019, Chemours adopted OGI as a component of its mechanical integrity and reliability programs, and purchased the first set of cameras^a,b.

Building on the success of the European adoption of OGI technology, Chemours began working with the cameras at its U.S. sites in early 2021. Eager to bolster its leak detection capability, the operator organized a demonstration of the OGI camera at one of its major manufacturing facilities. Technical personnel from across the site gathered for an hour-long presentation before the vendor placed the camera in the hands of the site’s process analyzer staff engineer.

Over the course of its first day of use, the OGI technology located opportunities for maintenance and inspection that were previously impossible. This initial positive trial and the subsequent productive days of monitoring led to both an acceptance of the technology and a return on the investment in the camera. OGI technology offers distinct and demonstrated advantages for operators that include fewer false-positive detections and more precise location of areas of concern.

The OGI technology’s capabilities were then showcased at other sites. Several types of leaks were among the training examples used to introduce OGI to Chemours’ Reliability Network (i.e., an interorganizational team that evaluates new technologies—also called an innovation division at some companies):

1. Pipe bridge leak: This “up-in-the-air,” pinhole-sized leak was discovered in piping (not on a connection point) that was transferring finished product into a storage tank during a periodic shutdown maintenance activity. This leak would not have been found by using an ambient air tester or a handheld analyzer (FIG. 3). Its discovery and subsequent repair eliminated a safety hazard, an out-of-compliance emission and a direct loss of profit. One of the benefits of OGI is the ability to quickly validate mechanical integrity after a site-wide maintenance shutdown. The camera’s sensitivity, precision and portability allow for a very efficient series of inspections (FIG. 4).
2. Truck-loading leaks: Leaks created when connecting hoses to trucks to transport product are generally not identified or gauged, resulting in incalculable losses between how much product a company may produce vs. how much is actually loaded and shipped. OGI cameras help organizations improve worker safety during loading, while also helping them better understand the product loss and increased return on investment.
3. Incorrectly recorded leaks: A leak identified with a handheld analyzer was to be confirmed with an OGI camera. The camera operator determined that the handheld analyzer had misdiagnosed the leak location. Had the leak been incorrectly tagged, a more than $5,000 repair would have been executed—emptying the trailer and replacing the incorrect component needlessly. Using OGI, the leak was correctly tagged and the correct component replaced, thus avoiding the need to empty the trailer and ensuring safer work conditions.

After the proprietary OGI cameras^a,c were introduced and demonstrated to various Chemour production sites, they were quickly adopted by local mechanical integrity teams. These teams maintain a steady training schedule on the technology to utilize its capabilities to optimize leak detection. This approach and team structure enhance mechanical integrity, reliability, and leak detection and repair programs, with the capability to be timelier and more proactive.

Several operators per shift are trained to use the OGI camera, providing them with a more effective means to find leaks. OGI provides surety to that investigation—whereas, the use of a handheld analyzer can require more time and still not yield localized leak sources. In addition, the OGI camera^c offers the utility to find natural gas leaks (e.g., from onsite furnaces).

Takeaways. While OGI cameras provide the petrochemical industry with a powerful addition to the corporate leak-detection toolbox, their effective use requires proper training. Many different variables can affect measurement, from ambient air temperature behind the leak and the angle of measurement, to the color palette applied and the distances from which the leak is measured. Ultimately, experience is the best teacher. The investment in OGI cameras provides numerous benefits. Worker safety is improved by providing confidence in predictive maintenance, proactive inspections and repair validation. Manufacturing organizations can also have confidence in their ability to meet corporate ESG goals. HP

NOTES

^a Teledyne FLIR GF304

^b Teledyne FLIR GF320

^c Teledyne FLIR GF77