Objective The extensive consumption of fossil fuels globally has led to significant environmental pollution and climate challenges. Hydrogen is recognized as a crucial energy carrier for the future due to its clean, pollution-free properties and abundant sources. From the perspective of economical efficiency and technical feasibility, transmitting hydrogen-blended natural gas through existing natural gas pipeline networks and facilitating hydrogen-blended combustion in end-user applications offers effective ways to achieve “dual carbon” goals.

Methods To investigate the influence of hydrogen blending on fuel gas characteristics and operational conditions of end-user equipment, this paper reviews the current research status of hydrogen-blended natural gas combustion technologies in China and abroad. The analysis encompasses multiple aspects, including gas interchangeability, flammable ranges, combustion characteristics, emission characteristics, and adaptability to end-user equipment. Comparative analyses highlight findings from various scholars. The influence patterns of hydrogen blending on fuel combustion characteristics and end-user applications are elaborated. Additionally, this paper summarizes the opportunities and challenges associated with the utilization of hydrogen-blended natural gas as a fuel.

Results Evaluating the operational availability of hydrogen-blended fuel gas from the standpoint of gas interchangeability is essential for existing natural gas equipment. The characteristics of hydrogen-blended fuel gas, such as wide combustible ranges, high combustion velocities, and short ignition delays, were identified as significant factors in enhancing combustion efficiency. Regarding emission characteristics, hydrogen blending has been shown to reduce CO and CO₂ emissions. However, the effects of hydrogen blending on NO_x emissions remain uncertain due to competing influences: the increase in flame temperature from hydrogen doping promotes NO_x formation, while the generation of additional OH and H radicals can suppress it. Furthermore, hydrogen blending may introduce safety concerns, including burner backfires and potential gas appliance explosions.

Conclusion This paper emphasizes the critical challenges associated with the widespread adoption of hydrogen-blended natural gas combustion technologies, which include achieving efficient and stable combustion, minimizing pollution emissions, and ensuring safety in the combustion process.