Two NETL researchers were awarded a patent for improvements to laser technology that can be used to detect CO₂ leaks more efficiently from underground carbon storage sites. The technology also holds potential for use as an online sensor in a range of other hostile environments that require environmental monitoring.

NETL’s Dustin McIntyre and Daniel Hartzler were recently awarded the fifth in a series of technology patents that cover aspects of a laser induced breakdown spectroscopy (LIBS) probe for underground storage site monitoring.

“Estimates are that carbon emissions should reach net-zero by 2050 to meet important climate targets,” McIntyre said. “Carbon capture is likely necessary to reach these targets, requiring a long-term storage solution such as underground carbon sequestration in geologic formations. However, as with any subsurface activity, leakage can occur, potentially impacting groundwater quality near storage sites. Rapid detection is essential to mitigate leakage.”

A loss of containment at an underground storage site can cause subsurface brines or CO₂ to migrate into aquifers and soils, potentially contaminating groundwater, a critical resource that millions in the United States rely on for drinking or for agriculture and industry.

Leakage can be detected by monitoring groundwater composition around underground storage sites known as geologic carbon sequestration (GCS) sites. A variety of analysis techniques are currently used to measure trace elements in groundwater. However, many of them have high equipment costs, operator training requirements, and lack portability, requiring samples to be collected in the field and transported to a laboratory for analysis.

That’s where NETL’s LIBS technology presents advantages. In LIBS, an intense pulsed laser is focused into or onto a sample, breaking down the target material into a plasma. As the plasma cools, its emission spectrum is measured, permitting the elements present to be identified and quantified based on the wavelength and intensity of their characteristic emission lines. Major advantages of LIBS include little to no sample preparation; a sensitivity to both light and heavy elements; durability for continuous, in-situ measurements in hostile environments; and potential for miniaturization.

The technology is titled “Downhole Laser System with an Improved Laser Output Production and Data Collection. The patent number is 11885746 and became active Jan. 30, 2024.

Hartzler explained that “The latest patent focuses on the components necessary to modify the laser output and improve the collection of light from the laser spark. The improved collection ensures higher data quality and more efficient collection and analysis of data. Those improvements make for better signal to noise and overall higher sensitivity for the device.”

The researchers added that rapid leak detection is essential, and the technology developed at NETL provides a detection system with many advantages over conventional detection approaches.

NETL is a DOE national laboratory that drives innovation and delivers technological solutions for an environmentally sustainable and prosperous energy future. By using its world-class talent and research facilities, NETL is ensuring affordable, abundant, and reliable energy that drives a robust economy and national security, while developing technologies to manage carbon across the full life cycle, enabling environmental sustainability for all Americans.