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2025 Vol.30, Issue 4

Research Article

Evaluation of Thermal Performance and Industrial Boiler by Carbon-Free Fuel Conversion

산업용 보일러의 무탄소 연료 전환에 따른 열 성능 평가

Jonghwan An12
,
Hyeonrok Choi12
,
Won Yang1
,
Changkook Ryu2
,
Seong-il Kim1†
안 종환12
,
최 현록12
,
양 원1
,
류 창국2
,
김 성일1†
1Low-carbon Emission Control Technology R&D Department, Research Institute of Sustainable Development Technology, Korea Institute of Industrial Technology
2School of Mechanical Engineering, Sungkyunkwan University
1한국생산기술연구원 지속가능기술연구소 저탄소배출제어연구부문
2성균관대학교 기계공학부
*Corresponding Author
31 December 2025. pp. 1-18
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Abstract

The conversion of industrial boilers to carbon-free fuels is one of the strategies for reducing carbon emissions. Hydrogen and ammonia, as representative carbon-free fuels, emit no CO2 during combustion, and when co-fired with LNG in existing boilers, affect flame temperature, flue gas composition, and flow rate, thereby influencing overall heat transfer characteristics. To evaluate these effects, a process simulation-based model dividing the boiler into radiation and convection zones was developed. The variations in radiative and convective heat transfer characteristics according to variation in the co-firing ratio were quantitatively analyzed, and boiler efficiency was assessed. Variations in flame temperature and flue gas composition affected furnace emissivity and radiative heat transfer, which in turn influenced flue gas temperature, flow rate, and convective heat transfer. As a result of the simulation, hydrogen co-firing increased radiative heat transfer and decreased convective heat transfer, leading to improved boiler efficiency. In contrast, ammonia co-firing decreased radiative heat transfer and increased convective heat transfer, resulting in degraded boiler efficiency. These findings are expected to serve as a basis for the design and operational optimization of industrial boilers utilizing carbon-free fuels.

Keywords
Industrial boiler
Hydrogen co-firing
Ammonia co-firing
Heat transfer mechanism
Boiler efficiency
References
1

Greenhouse Gas Inventory and Research Center (GIR), National Inventory Report for the Republic of Korea (1990–2022), Ministry of Environment, 2025.

2

J.H. Lee, J.H. Kim, H.J. Kim, D.H. Lee, J.H. Kim, S.H. Kang, D.W. Kim, Development trends of carbon-free fuel technologies using hydrogen and ammonia for carbon neutrality, J. Energy Climate Change, 19 (2024) 115-131.

3

International Energy Agency, Ammonia technology roadmap: Towards more sustainable nitrogen fertilizer production, 2021.

4

M.A. Habib, G.A. Abdulrahman, A.B. Alquaity, N.A. Qasem, Hydrogen combustion, production, and applications: A review, Alexandria Eng. J., 100 (2024) 182-207.

10.1016/j.aej.2024.05.030
5

Hydrogen Europe, Clean Hydrogen Monitor 2024, Hydrogen Europe, Brussels, 2024.

6

BDR Thermea Group, BDR Thermea tests first high-efficiency hydrogen boiler, 2019.

7

Hy4Heat, Hy4Heat Programme Overview, UK Department for Business, Energy & Industrial Strategy, 2022.

8

Viessmann, Viessmann H2-Ready boiler technology, Viessmann Official Website, 2023.

9

GRHYD Project, First hydrogen injection into a natural gas network in France, 2021.

10

U.S. Department of Energy, Department of Energy Hydrogen Program Plan, U.S. Department of Energy, Washington, D.C., 2024.

11

Ministry of Economy, Trade and Industry (METI), Japan Hydrogen Strategy, 2023.

12

Y. Huang, Y. Zhou, R. Zhong, C. Wei, B. Zhu, Hydrogen energy development in China: Potential assessment and policy implications, Int. J. Hydrogen Energy, 49 (2024) 659-669.

10.1016/j.ijhydene.2023.10.176
13

Ministry of Trade, Industry and Energy (MOTIE), Hydrogen Economy Roadmap of Korea, 2019.

14

K. Zhang, T. Luo, Y. Li, T. Zhang, X. Li, Z. Zhang, W. Gao, Effect of ignition, initial pressure and temperature on the lower flammability limit of hydrogen/air mixture, Int. J. Hydrogen Energy, 47 (2022) 15107-15119.

10.1016/j.ijhydene.2022.02.224
15

R. Li, Z. Liu, P. Li, M. Li, Y. Zhao, Investigation on the flammability limit and limiting oxygen concentration of N2-diluted H2/CO/air mixtures at high temperature and pressure, Fuel, 308 (2022) 121955.

10.1016/j.fuel.2021.121955
16

H. Miao, L. Lu, Z. Huang, Flammability limits of hydrogen-enriched natural gas, Int. J. Hydrogen Energy, 36 (2011) 6937-6947.

10.1016/j.ijhydene.2011.02.126
17

N. Schmidt, M. Müller, P. Preuster, L. Zigan, P. Wasserscheid, S. Will, Development and characterization of a low-NOx partially premixed hydrogen burner using numerical simulation and flame diagnostics, Int. J. Hydrogen Energy, 48 (2023) 15709-15721.

10.1016/j.ijhydene.2023.01.012
18

M. Dutka, M. Ditaranto, T. Løvås, NOx emissions and turbulent flow field in a partially premixed bluff body burner with CH4 and H2 fuels, Int. J. Hydrogen Energy, 41 (2016) 12397-12410.

10.1016/j.ijhydene.2016.05.154
19

A. Frassoldati, T. Faravelli, E. Ranzi, A wide range modeling study of NOx formation and nitrogen chemistry in hydrogen combustion, Int. J. Hydrogen Energy, 31 (2006) 2310-2328.

10.1016/j.ijhydene.2006.02.014
20

A. Hayakawa, K. Kobayashi, T. Kudo, Y. Okafor, E. Kurata, S. Somarathne, T. Nakamura, Laminar burning velocity and Markstein length of ammonia/air premixed flames at various pressures, Fuel, 159 (2015) 98-106.

10.1016/j.fuel.2015.06.070
21

X. Han, Y. Li, Z. Tian, H. Qi, Y. He, Y. Ju, Experimental and kinetic modeling study of laminar burning velocities of NH3/air, NH3/H2/air, NH3/CO/air and NH3/CH4/air premixed flames, Combust. Flame, 206 (2019) 214-226.

22

K.P. Shrestha, Y. Li, S. Somarathne, A. Hayakawa, H. Kobayashi, An experimental and modeling study of ammonia with enriched oxygen content and ammonia/hydrogen laminar flame speed at elevated pressure and temperature, Proc. Combust. Inst., 38 (2021) 2163-2174.

10.1016/j.proci.2020.06.197
23

R. Ichimura, K. Kitagawa, K. Sato, S. Hasegawa, Extinction limits of an ammonia/air flame propagating in a turbulent field, Fuel, 246 (2019) 178-186.

10.1016/j.fuel.2019.02.110
24

Y. Xia, Z. Tian, X. Han, Y. Li, Y. Ju, Turbulent burning velocity of ammonia/oxygen/nitrogen premixed flame in O2-enriched air condition, Fuel, 268 (2020) 117357.

10.1016/j.fuel.2020.117383
25

J. Li, H. Xiao, Z. Huang, A review on combustion characteristics of ammonia as a carbon-free fuel, Front. Energy Res., 9 (2021) 760356.

10.3389/fenrg.2021.760356
26

F. Ma, K. Li, C. Ji, Y. Wang, A review of current advances in ammonia combustion from the fundamentals to applications in internal combustion engines, Energies, 16 (2023) 6304.

10.3390/en16176304
27

H. Kobayashi, A. Hayakawa, K.D. Kunkuma A. Sakai, T. Okafor, Science and technology of ammonia combustion, Proc. Combust. Inst., 37 (2019) 109-133.

10.1016/j.proci.2018.09.029
28

S. Gubbi, J. Nogueira, E. Frassoldati, T. Faravelli, Evaluation of minimum NOx emission from ammonia combustion, J. Eng. Gas Turbines Power, 146 (2024) 031013.

10.1115/1.4064219
29

Y. Xu, S. Liu, Y. Zhao, Z. Huang, Mitigating CO2 emission in pulverized coal-fired power plant via co-firing ammonia: A simulation study of flue gas streams and exergy efficiency, Energy Convers. Manage., 256 (2022) 115328.

10.1016/j.enconman.2022.115328
30

S. Ishihara, J. Zhang, T. Ito, Numerical calculation with detailed chemistry on ammonia co-firing in a coal-fired boiler: Effect of ammonia co-firing ratio on NO emissions, Fuel, 274 (2020) 117742.

10.1016/j.fuel.2020.117742
31

S. Kim, M. Lim, Y. Lee, J. Lee, W. Yang, Evaluation of effects of ammonia co-firing on the thermal performances of supercritical pulverized coal and circulating fluidized bed boilers, Energy Convers. Manage., 276 (2023) 116528.

10.1016/j.enconman.2022.116528
32

H. Choi, Y. Lee, W. Yang, C. Ryu, S. Kim, Performance evaluation of the natural gas combined cycle with various hydrogen co-firing rates, Energy Convers. Manage., 341 (2025) 120051.

10.1016/j.enconman.2025.120051
33

H. Yang, X. Lin, H. Pan, S. Geng, Z. Chen, Y. Liu, Energy saving analysis and thermal performance evaluation of a hydrogen enriched natural gas-fired condensing boiler, Int. J. Hydrogen Energy, 48 (2023) 19279-19296.

10.1016/j.ijhydene.2023.02.027
34

IEA-ETSAP, Industrial combustion boilers - Technology brief I01, International Energy Agency - Energy Technology Systems Analysis Programme (ETSAP), 2010.

35

F.P. Incropera, D.P. DeWitt, T.L. Bergman, A.S. Lavine, Fundamentals of heat and mass transfer, 6th ed., Wiley, New York, 1996.

36

M.H. Bordbar, G. Węcel, T. Hyppänen, A line by line based weighted sum of gray gases model for inhomogeneous CO2-H2O mixture in oxy-fired combustion, Combust. Flame, 161 (2014) 2435-2445.

10.1016/j.combustflame.2014.03.013
37

H. Bordbar, G.C. Fraga, S. Hostikka, An extended weighted-sum-of-gray-gases model to account for all CO2-H2O molar fraction ratios in thermal radiation, Int. Commun. Heat Mass Transf., 110 (2020) 104400.

10.1016/j.icheatmasstransfer.2019.104400
38

P. Basu, C. Kefa, L. Jestin, Boilers and burners: design and theory, Springer Science & Business Media, 2012.

39

S.I. Kim, H.G. Kwak, W. Yang, Process simulation of the effect of ammonia co-firing on the supercritical boiler system for reduction of greenhouse gas, J. Korean Soc. Combust., 26(4) (2021) 1-12.

10.15231/jksc.2021.26.4.001
40

W. Sutherland, The viscosity of gases and molecular force, Phil. Mag., 36 (1893) 507-531.

10.1080/14786449308620508
41

NIST, Reference Fluid Thermodynamic and Transport Properties Database (REFPROP): Version 10, Available at: <https://www.nist.gov/srd/refprop> (accessed 22 October 2020).

42

C. R. Wilke, A viscosity equation for gas mixtures, J. Chem. Phys., 18 (1950) 517-519.

10.1063/1.1747673
43

M. Xu, X. Xu, Y. Wang, H. Li, J. Zhang, Effect of hydrogen-blending ratio and wall temperature on establishment, NO formation, and heat transfer of hydrogen-enriched methane MILD combustion, Int. J. Hydrogen Energy, 44 (2019) 28204-28218.

44

IPIECA, Pinch Analysis - Energy Efficiency Compendium, IPIECA, London, 2022.

45

T. Wang, H. Zhang, Y. Zhang, H. Wang, J. Lyu, G. Yue, Efficiency and emissions of gas-fired industrial boiler fueled with hydrogen-enriched natural gas: A case study of 108 t/h steam boiler, Int. J. Hydrogen Energy, 47 (65) (2022) 28188-28203.

10.1016/j.ijhydene.2022.06.121
Information
  • Publisher :The Korean Society of Combustion
  • Publisher(Ko) :한국연소학회
  • Journal Title :Journal of the Korean Society of Combustion
  • Journal Title(Ko) :한국연소학회지
  • Volume : 30
  • No :4
  • Pages :1-18
  • Received Date : 2025-07-10
  • Revised Date : 2025-09-26
  • Accepted Date : 2025-09-26
  • DOI :https://doi.org/10.15231/jksc.2025.30.4.001
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