Hydrogen for decarbonized energy systems: combustion characteristics, and applications in furnaces, engines, turbines, and microgrids

Abstract

Abstract

Hydrogen is becoming a key part of global plans to cut carbon emissions in power generation, transportation, industrial heat, and integrated microgrid systems. This paper examines the production pathways of hydrogen specifically grey, blue, green, pink, brown/black, and naturally occurring white hydrogen and assesses their techno-economic maturity in relation to projected demand trajectories through 2050. The combustion properties of hydrogen are analyzed comprehensively, highlighting its extensive flammability limits, elevated flame velocities, minimal ignition energy requirements, diffusive-thermal instabilities, and tendencies for NOₓ formation. These characteristics have a big impact on how hydrogen-fired furnaces, spark-ignition (SI) and compression-ignition (CI) engines, and advanced gas turbine combustors are designed and used. In furnaces, using hydrogen-enriched and pure-H₂ operation can greatly lower CO₂ levels, but the burners need to be redesigned to stop flashback and NOₓ. SI hydrogen engines are getting continue to improve, thanks to direct injection, Exhaust Gas Recirculation (EGR), boosting, and knock mitigation. Hydrogen-diesel dual-fuel CI systems, on the other hand, are very efficient and produce less carbon. Gas turbines have problems with flashback, thermoacoustic instabilities, and mixing non-uniformities. This has led OEMs to use multi-nozzle, cluster-type, and low-NOₓ combustor architectures. The study also talks about how hydrogen is used in hybrid renewable microgrids, which use electrolysis, Combined Heat and Power (CHP) units, and thermal recovery to store energy for a long time. Collectively, the findings demonstrate hydrogen’s strong potential to decarbonize multi-sector energy systems.