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Effect of hydrogen co-firing on combustion efficiency, steam production, and emissions of a B7 diesel water-tube boiler: An experimental and semi-empirical combustion modeling study

Rattanakosin College for Sustainable Energy and Environment, Rajamangala University of Technology Rattanakosin (RMUTR), Thailand

Received: 26 May 2026; Revised: 17 Jul 2026; Accepted: 18 Sep 2026; Available online: 3 Oct 2026; Published: 1 Nov 2026.
Editor(s): H Hadiyanto
Open Access Copyright (c) 2026 The Author(s). Published by Centre of Biomass and Renewable Energy (CBIORE)
Creative Commons License This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

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Abstract

Hydrogen co-firing provides a near-term opportunity to reduce emissions from industrial steam boilers, particularly in Thailand where B7 diesel containing 7% palm-oil fatty acid methyl ester (FAME) is the required diesel fuel. However, clear evidence of this system for this type of boiler is still insufficient. In this study, a systematic investigation was performed on a 1,000 kg/h water-tube boiler (Kawasaki 15750) at hydrogen/diesel energy proportions varying from 0 to 30% under a constant low-fire condition. Supplemental oxygen was precisely controlled to maintain an almost constant stoichiometric concentration. The results were further analyzed with a semi-empirical combustion model using extended Zeldovich NOx kinetics. At an H2/diesel energy ratio of 30%, steam production increased by 24.3%, from 323.8 to 402.4 kg/hr. Although diesel consumption rate is almost constant, the addition of hydrogen increased overall fuel consumption energy input by 29 %. The concentration of CO decreased by 73.4%, from 107.0 to 28.5 ppm, and CO₂ emission per unit of steam decreased by 20.1%, from 196.9 to 157.3 g/kg. Measured NO₂ increased by 70.8%, consistent with predicted NOₓ ranges of 36–150 ppm at baseline and 62–256 ppm at 30% H₂, depending on the assumed NO₂/NOₓ fraction. Multivariable analysis indicated that hydrogen addition had a greater impact on the emission response than oxygen enrichment. System efficiency, computed using an input-output method based on ASME PTC 4.1, decreased by 3.60 percentage points. Because the drum water inventory was not recorded at the beginning and end of each test, this decrease reflected a maximum limit on the efficiency loss. Presently, the price of hydrogen costs 753 THB/kg (23 USD/kg). So, hydrogen co-firing was still more expensive than diesel-only operation at all tested ratios. As the price of hydrogen decreases to approximately 120–230 THB/kg (3.7–7.0 USD/kg), which is within the range projected by IRENA for green hydrogen before 2030, hydrogen co-firing could become economically competitive. Therefore, under current hydrogen price, the hydrogen co-firing mainly contributes to increased steam production and lower CO and CO₂ emissions, but it does not provide fuel-cost savings and results in higher NOₓ emissions.

Keywords: B7 biodiesel; Boiler efficiency; Boiler retrofit; CO reduction; Combustion emissions; Hydrogen co-firing; NOₓ; Semi-empirical combustion model; Steam production; Water-tube boiler

Article Metrics:

  1. ASME. (1964). PTC 4.1-1964, Steam Generating Units. American Society of Mechanical Engineers
  2. ASME. (2018). PTC 19.1 Test Uncertainty (2018 (Reaffirmed 2024) ed.). American Society of Mechanical Engineers. https://www.asme.org/codes-standards/find-codes-standards/test-uncertainty
  3. Boulahlib, M. S., Medaerts, F., & Boukhalfa, M. A. (2021). Experimental study of a domestic boiler using hydrogen methane blend and fuel-rich staged combustion. International Journal of Hydrogen Energy, 46(75), 37628-37640. https://doi.org/10.1016/j.ijhydene.2021.01.103
  4. Burnham, K. P., & Anderson, D. R. (2002). Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach (2nd ed.). Springer. https://doi.org/10.1007/b97636
  5. Capurso, T., Stefanizzi, M., Torresi, M., & Camporeale, S. M. (2022). Perspective of the role of hydrogen in the 21st century energy transition. Energy Conversion and Management, 251. https://doi.org/10.1016/j.enconman.2021.114898
  6. Department of Energy Business. (2020). Notification of the Department of Energy Business Re: Characteristics and Quality Specifications of Diesel Fuel, B.E. 2563 (2020). In Royal Thai Government Gazette (Vol. 137, pp. 11). Bangkok, Thailand: Ministry of Energy
  7. Department of Industrial Works. (2024). Retrieved Data on Boiler Registration
  8. Dryer, F. L., & Glassman, I. (1973). High temperature oxidation of CO and CH4. Symposium (International) on Combustion, 14(1), 987-1003. https://doi.org/10.1016/S0082-0784(73)80090-6
  9. Energy Policy and Planning Office. (2023). Annual Carbon Dioxide Emissions from the Energy Sector. Bangkok: Ministry of Energy
  10. Energy Policy and Planning Office, Energy Research Institute, Chulalongkorn University, & Energy Research and Development Institute, Chiang Mai University. (2021). A Study Project on the Development of Hydrogen Production and Use to Promote Renewable Energy
  11. EPRI. (2020). Phase II Assessment of NO2/NOx Ratios at Fossil Fuel Power Plants. Electric Power Research Institute
  12. Erdener, B. C., Sergi, B., Guerra, O. J., Lazaro Chueca, A., Pambour, K., Brancucci, C., & Hodge, B.-M. (2023). A review of technical and regulatory limits for hydrogen blending in natural gas pipelines. International Journal of Hydrogen Energy, 48(14), 5595-5617. https://doi.org/10.1016/j.ijhydene.2022.10.254
  13. Fenimore, C. P. (1971). Formation of nitric oxide in premixed hydrocarbon flames. Symposium (International) on Combustion, 13(1), 373-380. https://doi.org/10.1016/S0082-0784(71)80040-1
  14. Gersen, S., Slim, B., Zeijlmaker, R., van Essen, M., & Tichelaar, R. (2020). The Development of a Natural Gas/Hydrogen Boiler System. in IGRC 2020. Muscat
  15. Glanville, P., Fridlyand, A., Sutherland, B., Liszka, M., Zhao, Y., Bingham, L., & Jorgensen, K. (2022). Impact of Hydrogen/Natural Gas Blends on Partially Premixed Combustion Equipment: NOx Emission and Operational Performance. Energies, 15(5). https://doi.org/10.3390/en15051706
  16. Glarborg, P., Miller, J. A., Ruscic, B., & Klippenstein, S. J. (2018). Modeling nitrogen chemistry in combustion. Progress in Energy and Combustion Science, 67, 31-68. https://doi.org/10.1016/j.pecs.2018.01.002
  17. Goodwin, D. G., Moffat, H. K., Schoegl, I., Speth, R. L., & Weber, B. W. (2025). Cantera: An Object-oriented Software Toolkit for Chemical Kinetics, Thermodynamics, and Transport Processes (Version 3.2.0). https://doi.org/10.5281/zenodo.17620923
  18. Heeley, A. D., Finney, K. N. N., Szuhánszki, J., Gheit, A., Hee, J. L., & Pourkashanian, M. (2026). Pilot scale demonstration of potential for decarbonisation of industrial heating processes using hydrogen cofiring. Frontiers in Fuels, 4, 1756561. https://doi.org/10.3389/ffuel.2026.1756561
  19. Hosseini, S. H., Tsolakis, A., Alagumalai, A., Mahian, O., Lam, S. S., Pan, J., Peng, W., Tabatabaei, M., & Aghbashlo, M. (2023). Use of hydrogen in dual-fuel diesel engines. Progress in Energy and Combustion Science, 98. https://doi.org/10.1016/j.pecs.2023.101100
  20. IEA. (2024). Southeast Asia Energy Outlook 2024. https://www.iea.org/reports/southeast-asia-energy-outlook-2024
  21. IEA. (2025). Renewables 2025. https://www.iea.org/reports/renewables-2025
  22. IEA. (2026). Energy Technology Perspectives 2026. https://www.iea.org/reports/energy-technology-perspectives-2026
  23. IRENA. (2020). Green Hydrogen Cost Reduction: Scaling up Electrolysers to Meet the 1.5 °C Climate Goal. International Renewable Energy Agency
  24. Jankowski, R., Ślefarski, R., Bauma, I., & Varlamov, G. (2025). Thermal and Emission Performance Evaluation of Hydrogen-Enriched Natural Gas-Fired Domestic Condensing Boilers. Energies, 18(13), 3240. https://doi.org/10.3390/en18133240
  25. Jayabal, R., & Sivanraju, R. (2025). Environmental and Emission Analysis of Biodiesel/Bioethanol/Nanoparticles Blends With Hydrogen Addition in Diesel Engine. Energy Science & Engineering, 13(8), 4024-4031. https://doi.org/10.1002/ese3.70151
  26. Jung, L., Mages, A., & Sauer, A. (2024). Numerical Investigation and Simulation of Hydrogen Blending into Natural Gas Combustion. Energies, 17(15), 3819. https://doi.org/10.3390/en17153819
  27. Kannan, J., Gadalla, M., Tekgül, B., Karimkashi, S., Kaario, O., & Vuorinen, V. (2021). Large-eddy simulation of tri-fuel ignition: diesel spray-assisted ignition of lean hydrogen–methane–air mixtures. Combustion Theory and Modelling, 25(3), 436-459. https://doi.org/10.1080/13647830.2021.1887525
  28. Khiraiya, K., Ramana, P. V., Panchal, H., Sadasivuni, K. K., Doranehgard, M. H., & Khalid, M. (2021). Diesel-fired boiler performance and emissions measurements using a combination of diesel and palm biodiesel. Case Studies in Thermal Engineering, 27. https://doi.org/10.1016/j.csite.2021.101324
  29. Laget, H., Griebel, P., Gooren, L., Hampp, F., Jouret, N., & Lammel, O. (2023). Demonstration of Natural Gas and Hydrogen Cocombustion in an Industrial Gas Turbine. Journal of Engineering for Gas Turbines and Power, 145(4), 041007. https://doi.org/10.1115/1.4056046
  30. Lan, Y., Wang, Z., Xu, J., & Yi, W. (2024). The Impact of Hydrogen on Flame Characteristics and Pollutant Emissions in Natural Gas Industrial Combustion Systems. Energies, 17(19). https://doi.org/10.3390/en17194959
  31. Lin, K.-W., & Wu, H.-W. (2023). Emissions and energy/exergy efficiency in an industrial boiler with biodiesel and other fuels. Case Studies in Thermal Engineering, 50. https://doi.org/10.1016/j.csite.2023.103474
  32. Long Huynh, D. N., Nguyen, T. H., Nguyen, D. C., Vo, A. V., Nguyen, D. T., Nguyen, V. Q., & Le, H. C. (2024). Using hydrogen as potential fuel for internal combustion engines: A comprehensive assessment [Emission reduction; Internal combustion engines; Alternative fuel; Hydrogen; Sustainability; Net-zero goal]. International Journal of Renewable Energy Development, 14(1), 83-103. https://doi.org/10.61435/ijred.2025.60707
  33. Ministry of Industry. (2006). Notification of the Ministry of Industry on the Determination of Air Pollutant Concentrations Emitted from Factories, B.E. 2549 (2006) (Royal Thai Government Gazette, Vol. 123, Special Part 125 Ngo, pp. 7–11, 4 December 2006)
  34. Ministry of Industry. (2026). Notification of the Ministry of Industry on the Determination of Air Pollutant Concentrations Emitted from the Stacks of Boilers and Thermal Oil Heaters of Factories Located in the Bangkok Metropolitan Area, B.E. 2569 (2026) (Royal Thai Government Gazette, Vol. 143, Special Part 41 Ngo, pp. 49–51, 12 February 2026)
  35. NASA. (1997). Safety Standard for Hydrogen and Hydrogen Systems: Guidelines for Hydrogen System Design, Materials Selection, Operations, Storage, and Transportation (NSS 1740.16)
  36. Nemitallah, M. A., Aliyu, M., Hamdy, M., & Habib, M. A. (2024). Retrofitting Natural Gas–Fired Boiler for Hydrogen Combustion: Operational Performance and NOx Emissions. Journal of Energy Resources Technology, 146(10), 1-12. https://doi.org/10.1115/1.4065205
  37. Nguyen, D., Nguyen, L. H., Nguyen, D. T., Chung, N., & Truong, T. H. (2026). Integrated multi-objective optimization of fuel injection and engine strategy in oxyhydrogen/producer gas-powered dual-fuel diesel engine. International Journal of Renewable Energy Development, 15(1), 147-159. https://doi.org/10.61435/ijred.2026.62062
  38. Pan, H., Geng, S., Yang, H., Zhang, G., Bian, H., & Liu, Y. (2023). Influence of H2 blending on NOx production in natural gas combustion: Mechanism comparison and reaction routes. International Journal of Hydrogen Energy, 48(2), 784-797. https://doi.org/10.1016/j.ijhydene.2022.09.251
  39. Periyathambi, V., Ezhumalai, M., Govindasamy, M., Dhairiyasamy, R., Varshney, D., & Singh, S. (2025). Balancing Efficiency and Emissions: A Study on Biodiesel‐Hydrogen Dual‐Fuel Engine Performance Under Varying Injection Timings. Engineering Reports, 7(5), e70174. https://doi.org/10.1002/eng2.70174
  40. Premsathit, S., Palamanit, A., Mohideen Batcha, M. F., & Wae-hayee, M. (2025). Study of Diesel Combustion Combined with Hydrogen using an Industrial Burner. International Journal of Integrated Engineering, 17(8), 181-189. https://journal.uthm.edu.my/index.php/ijie/article/view/24025
  41. Ranzi, E., Frassoldati, A., Grana, R., Cuoci, A., Faravelli, T., Kelley, A. P., & Law, C. K. (2012). Hierarchical and comparative kinetic modeling of laminar flame speeds of hydrocarbon and oxygenated fuels. Progress in Energy and Combustion Science, 38(4), 468-501. https://doi.org/10.1016/j.pecs.2012.03.004
  42. Ranzi, E., Frassoldati, A., Stagni, A., Pelucchi, M., Cuoci, A., & Faravelli, T. (2014). Reduced Kinetic Schemes of Complex Reaction Systems: Fossil and Biomass-Derived Transportation Fuels. International Journal of Chemical Kinetics, 46(9), 512-542. https://doi.org/10.1002/kin.20867
  43. Schwarz, S., Daurer, G., Gaber, C., Demuth, M., Prieler, R., & Hochenauer, C. (2024). Experimental investigation of the combustion characteristics in oxy-fuel combustion of hydrogen-enriched natural gas on a semi-industrial scale. International Journal of Hydrogen Energy, 49, 323-337. https://doi.org/10.1016/j.ijhydene.2023.07.268
  44. Smith, G. P., Golden, D. M., Frenklach, M., Moriarty, N. W., Eiteneer, B., Goldenberg, M., Bowman, C. T., Hanson, R. K., Song, S., Gardiner, W. C., Lissianski, V. V., & Qin, Z. (1999). GRI-Mech 3.0. http://combustion.berkeley.edu/gri-mech/version30/text30.html
  45. Song, Y., Marrodan, L., Vin, N., Herbinet, O., Assaf, E., Fittschen, C., Stagni, A., Faravelli, T., Alzueta, M. U., & Battin-Leclerc, F. (2019). The sensitizing effects of NO2 and NO on methane low temperature oxidation in a jet stirred reactor. Proceedings of the Combustion Institute, 37(1), 667-675. https://doi.org/10.1016/j.proci.2018.06.115
  46. Spirax Sarco. (2026). Separators. Learn about Steam: Pipeline Ancillaries, Block 12.5. https://www.spiraxsarco.com/learn-about-steam/pipeline-ancillaries/separators
  47. Sun, C., Wang, T., Wang, P., Zhang, Y., Cui, C., Lu, Y., Liu, W., Zhang, Y., & Zhang, Y. (2024). Numerical Simulation and Field Experimental Study of Combustion Characteristics of Hydrogen-Enriched Natural Gas. Processes, 12(7), 1325. https://doi.org/10.3390/pr12071325
  48. Turns, S. R. (2012). An Introduction to Combustion: Concepts and Applications (3rd ed.). McGraw-Hill
  49. Wang, T., Zhang, H., Zhang, Y., Wang, H., Lyu, J., & Yue, G. (2022). Efficiency and emissions of gas-fired industrial boiler fueled with hydrogen-enriched nature gas: A case study of 108 t/h steam boiler. International Journal of Hydrogen Energy, 47(65), 28188-28203. https://doi.org/10.1016/j.ijhydene.2022.06.121
  50. Wang, Z., & Yang, X. (2024). NOx Formation Mechanism and Emission Prediction in Turbulent Combustion: A Review. Applied Sciences, 14(14). https://doi.org/10.3390/app14146104
  51. Warasinchai, S., & Kachapongkun, P. (2026). Effects of Hydrogen Gas Addition on Combustion Efficiency and Pollutant Emissions in a 1-ton/hour Diesel B7 Boiler [in Thai]. The Journal of Industrial Technology, in press
  52. Xin, Y., Wang, K., Zhang, Y., Zeng, F., He, X., Takyi, S. A., & Tontiwachwuthikul, P. (2021). Numerical Simulation of Combustion of Natural Gas Mixed with Hydrogen in Gas Boilers. Energies, 14(21). https://doi.org/10.3390/en14216883

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