In the efforts to address near-term decarbonization by utilization of Hydrogen as a fuel, industrial combustion devices lag other platforms such as gas turbines and fuel cells in their capability to use hydrogen effectively and cleanly. Through the proposed project, ClearSign Technologies Corporation will develop industrial-scale fuel-flexible process burners for the refining and petrochemical industry, capable of operating on up to 100% Hydrogen as well as blends of Natural Gas and Hydrogen while demonstrating sub-5 ppm NOx emissions. The burners will achieve low NOx emissions without the use of any diluents, other than air, without expensive exhaust post-treatment techniques like Selective Catalytic Reduction, and without any catalysts or chemicals. ClearSign currently has ultra-low NOx burners for different application areas including process burners, boiler burners, and flare burners. The ClearSign CoreTM process burners range from 1 to 20 MMBtu/hr in size and can currently operate on Natural Gas, various refinery fuels including ones containing up to 50% Propane, and up to 85% Hydrogen (by volume). The burners utilize premixed combustion, internally induced Flue Gas Recirculation (iFGR), enhanced flame radiation, and a distal flameholder, to provide extremely low NOx emissions. Phase 1 of this project will work to demonstrate sub-5 ppm NOx (corrected to 3% O2) for a 2 MMBtu/hr process burner operating up to 100% H2 fuel. Phase 2 will focus on scaling the burner ranging from 2 MMBtu/hr up to 20 MMBtu/hr as well as extend the design to multi-burner furnaces which are common in refining process heater applications.