Patented Innovation Allows Affordable Long-Range Detection of CO2 Leaks at Underground Storage Sites and Pipelines

NETL researchers have received a patent for an inexpensive sensing platform capable of long-range real-time monitoring to detect carbon dioxide (CO₂) leaks at remote underground storage facilities and in pipelines.

NETL demonstrated how the quicker and cost-effective real-time data collection and analysis made possible by the technology has potential to support a wide range of industries and applications, including infrastructure monitoring, oil and gas exploration and increased power grid efficiency.

The technology, known as a mixed-matrix composite integrated fiber optic CO₂ sensor, offers a more effective way to monitor CO₂ over large geographical areas with varied terrain or in areas not accessible to conventional sensing technologies.

In the patented technology, a mixed-matrix composite sensor material made up of plasmonic nanocrystals and zeolites are embedded in a polymer matrix coating on a fiber optic sensor.

• A mixed matrix composite is a type of composite material where two or more different materials are combined to create a material with properties that are superior to those of the individual components.
• Plasmonic nanocrystals, also known as plasmonic nanoparticles, are small metallic particles that exhibit unique optical properties due to the interaction of light with their free electrons.
• A zeolite is a mineral with a structure that enables it to take in and lose liquid easily. There are many different types of zeolites.

According to NETL's Ki-Joong Kim, a co-inventor of the technology with Jeffrey Culp and James Ellis, the innovation showed an ability to sense CO₂ in the presence of other gases and an ability to monitor dissolved CO₂ in natural water. He added that reproducibility was confirmed over many cycles, both in a laboratory setting and in the field.

"For safe, reliable, and robust geological storage or utilization in applications like enhanced oil recovery of CO₂ from industrial processes, strategies for leak detection, quantification and management are crucial," Kim said. ^"One strategy is monitoring solution-phase chemistry in geological formations. That requires techniques for long-range and real-time monitoring of gas-phase and dissolved CO₂ leak detection in natural water. This technology can provide that capability."

The innovation is a notable improvement over current monitoring techniques that require a large sensing volume and an expensive, bulky optical system that make them unsuitable for remote sensing applications. Kim said the NETL technology uses a wireless telemetry system to transfer data in real time through cellular lines to provide on-line monitoring capabilities.

The work supports the U.S. Department of Energy's (DOE) efforts to expand America's affordable and reliable energy and natural resources to restore American prosperity and rebuild the nation's economic and national security.

US Patent Number 12,216,310 for the innovation was issued in February 2025.