ClearSign Technologies Corporation, with project management and financial support from NETL, is working to advance industrial fueling technologies that will address the practical demands of U.S. refineries and chemical processing facilities by enabling the cost-effective use of diverse fuel and natural gas mixed gas blends in industrial heating applications.

Many industrial operators currently have access to a variety of opportunity fuels or specific gas compositions that remain untapped due to the inability to meet regulatory nitrogen oxide (NOx) emission limits in place to help protect air quality and respiratory health.

ClearSign’s “Flexible Fuel Ultra-Low NOx Process Burner” project, which is nearing its scheduled completion and marking a significant 2.5-year effort, resolves this issue by facilitating fuel switching and optimization without compromising emissions compliance. This innovation allows industrial facilities to enhance operational flexibility, reduce costs associated with fuel procurement and maintain uninterrupted operations — all of which will help provide Americans with more affordable, reliable and secure energy.

The ClearSign Core™ burner, scaled to 8 million British thermal units per hour, has demonstrated consistent performance across a range of fuel compositions, including 100% natural gas and various intermediate blends. It has achieved ultra-low NOx emissions that are consistently below 5 parts per million. This is accomplished through integrated features such as internally induced flue gas recirculation, fuel-lean premixing and a patented distal flameholder, all contained within a compact burner head designed for easy retrofitting into existing heater infrastructure.

“NETL’s investment in ClearSign’s technology is opening up significant operational advantages for industry,” said Drew O’Connell, NETL federal project manager. “This solution allows companies to effectively utilize a broader spectrum of available fuels, ensuring they operate within permitted NOx limits without needing additional post-combustion controls like selective catalytic reduction or diluents.”

The project, which was made possible through a $1.65 million Phase II Small Business Innovation Research (SBIR) award from the U.S. Department of Energy (DOE), is preparing for the next critical stage: field demonstrations at operational industrial sites.

Project leaders are actively discussing opportunities with multiple potential host facilities to pilot the technology in full-scale furnaces. These demonstrations are crucial for validating the burner’s performance under actual production conditions and will inform subsequent commercialization strategies.

By enabling energy-intensive industries to interchangeably use various available fuels while adhering to strict NOx regulations, ClearSign’s NETL-supported technology offers a practical and economical solution. This advancement will significantly improve operational resilience and competitiveness within the domestic refining and chemical production sectors, aligning with NETL’s commitment to providing technological solutions for U.S. industrial needs, increasing industry partnerships and advancing hydrocarbon technologies.

This initiative underscores the impact of DOE’s SBIR program, which NETL helps administer, by empowering small businesses, such as Tulsa-based ClearSign, to develop technologies that address national industrial challenges and strengthen U.S. manufacturing innovation.

NETL is a U.S. Department of Energy (DOE) national laboratory dedicated to innovating and accelerating the nation’s energy solutions in hydrocarbon, geothermal energy and critical minerals production. With research sites in Albany, Oregon; Morgantown, West Virginia; and Pittsburgh, Pennsylvania, NETL operates as one laboratory to create advanced energy technologies that support DOE’s mission and enable affordable, reliable and secure energy to fuel human prosperity.