ReaxFF Molecular Dynamics Simulation of Decomposition Mechanism and Kinetics of Liquid Hydrocarbon Fuel with Chemical Initiators

Eungyo Choi; Byung Hun Jeong; Dongchang Park; Jung Hoon Park; Hyung Sub Sim

doi:10.15231/jksc.2025.30.1.057

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2025 Vol.30, Issue 1 Preview Page Next Page

Research Article

ReaxFF Molecular Dynamics Simulation of Decomposition Mechanism and Kinetics of Liquid Hydrocarbon Fuel with Chemical Initiators 화학 개시제 첨가 액체 탄화수소 연료의 분해 메커니즘 및 반응 동역학에 관한 ReaxFF 분자동역학 시뮬레이션 연구

31 March 2025. pp. 57-66

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Abstract

Understanding the decomposition processes of liquid hydrocarbon fuel with chemical initiators in the regenerative cooling systems of scramjet propulsion is crucial for improving its thermal management capabilities. This study theoretically investigates the effects of chemical initiators on the decomposition of exo-tetrahydrodicyclopentadiene(exo-THDCPD) using ReaxFF molecular dynamics(MD) simulations. Triethylamine(TEA), di-tert-butyl peroxide(DTBP), and cumene hydroperoxide(CHP) were examined as potential initiators, with simulations performed at various temperatures using the Berendsen thermostat and the CHON-2019 force field. MD results demonstrate that the initiators significantly affect conversion rates, product distributions, and reaction pathways. The addition of TEA and CHP enhanced fuel conversion by reducing activation energy, whereas DTBP had minimal impact. Product analysis revealed that DTBP increased the selectivity of C₁-C₄ paraffins and C₂-C₄ olefins, while TEA promoted CH₄ and C₂H₆ formation. Moreover, CHP increased the selectivity of PAH precursors in the early stage, suggesting a higher tendency for coke formation. Reaction pathway analysis further confirmed that the initiators decompose, rapidly generating radicals that facilitate hydrogen abstraction and accelerate fuel decomposition. These findings provide a basis for optimizing fuel decomposition and thermal management performance through the use of chemical initiators.

Keywords

Molecular dynamics

Chemical initiators

Decomposition

Reaction mechanism

exo-THDCPD

References

National Research Council, Review and evaluation of the air force hypersonic technology program, National Academy Press, Washington D.C., (1998) 5-17.

D.M. Van Wie, S.M. D'Alessio, M.E. White, Hypersonic air-breathing propulsion, Johns Hopkins APL Technology Digest, 26(4) (2005) 430-437.

D.R. Sobel, L.J. Spadaccini, Hydrocarbon fuel cooling technologies for advanced propulsion, J. Eng. Gas Turbine. Power, 119(2) (1997) 344-351.

10.1115/1.2815581

T. Edwards, Liquid fuels and propellants for aerospace propulsion: 1903-2003, J. Propuls. Power, 19(6) (2003) 1089-1107.

10.2514/2.6946

T. Edwards, Cracking and deposition behavior of supercritical hydrocarbon aviation fuels, Combust. Sci. Technol., 178 (2006) 307-334.

10.1080/00102200500294346

N. Gascoin, P. Gillard, S. Bernard, M. Bou chez, Characterisation of coking activity during supercritical hydrocarbon pyrolysis, Fuel Process. Technol., 89 (2008) 1416-1428.

10.1016/j.fuproc.2008.07.004

H. Lander, A. C. Nixon, Endothermic fuels for hypersonic vehicles, J. Aircr., 8 (1971) 200-207.

10.2514/3.44255

D. T. Wickham, J. R. Engel, S. Rooney, B. D. Hitch, Additives to improve fuel heat sink capacity in air/fuel heat exchangers, J. Propuls. Power, 24 (2008) 55-63.

10.2514/1.24336

C. Qi, Q. H. Lin, Y. Y. Li, S. P. Pang, R. B. Zhang, C-N bond dissociation energies: An assessment of contemporary DFT methodologies, Journal of Molecular Structure: THEOCHEM, 961(1-3) (2010) 97-100.

10.1016/j.theochem.2010.09.005

X. Shi, Y. Pan, Z. Gong, X. Zhang, H. Zhu, Pyrolysis behaviors of di-tert-butyl peroxide in gas and liquid phases: A ReaxFF molecular dynamics simulation, Fuel, 351 (2023) 128930.

10.1016/j.fuel.2023.128930

Z. Jia, W. Zhou, W. Yu, Z. Han, Experimental investigation on pyrolysis of n-decane initiated by nitropropane under supercritical pressure in a miniature tube, Energy and Fuels, 33(6) (2019) 5529-5537.

10.1021/acs.energyfuels.9b00593

K. J. Laidler, J. Keith, Chemical kinetics, New York: McGraw-Hill, (1965).

V. Kalyan, S. Konda, K. B. Vipin, S. Dinda, In-situ cooling capacity of a hydrocarbon fuel under supercritical conditions: heat sink, coke deposition, and impact of initiator, Fuel Communications, 12 (2022) 100075.

10.1016/j.jfueco.2022.100075

S. Priyadarshi, M. S. N. Kishore, R. Vinu, Analytical pyrolysis of jet fuel using different free radical initiators to produce low molecular weight hydrocarbons, J. Anal. Appl. Pyrolysis, 162 (2022) 105430.

10.1016/j.jaap.2021.105430

G. He, X. Wu, D. Ye, Y. Guo, S. Hu, Y. Li, W. Fang, Hyperbranched poly (amidoamine) as an efficient macroinitiator for thermal cracking and heat-sink enhancement of hydrocarbon fuels, Energy and Fuels, 31(7) (2017) 6848-6855.

10.1021/acs.energyfuels.7b00751

R. Chen, Y. Liu, C. Yin, L. Wang, L. Zhang, J. Song, H. Sun, A study on the pyrolysis of n-hexane initiated by 1-nitropropane: Molecular dynamics simulations and SVUV-PIMS experiments, J. Anal. Appl. Pyrolysis, 175 (2023) 106194.

10.1016/j.jaap.2023.106194

Q. D. Wang, X. X. Hua, X. M. Cheng, J. Q. Li, X. Y. Li, Effects of Fuel Additives on the Thermal Cracking of n-Decane from Reactive Molecular Dynamics, J. Phys. Chem. A, 116(15) (2012) 3794-3801.

10.1021/jp300059a

Y. Guan, J. Lou, R. Liu, H. Ma, J. Song, Reactive molecular dynamics simulation on thermal decomposition of n-heptane and methylcyclohexane initiated by nitroethane, Fuel, 261 (2020) 116447.

10.1016/j.fuel.2019.116447

K. Chenoweth, A. C. T. Van Duin, W. A.Goddard, ReaxFF reactive force field for molecular dynamics simulations of hydrocarbon oxidation, J. Phys. Chem. A, 112 (2008) 1040-1053.

10.1021/jp709896w

M. Kowalik, C. Ashraf, B. Damirchi, D. Akbarian, S. Rajabpour, A. C. T. Van Duin, Atomistic scale analysis of the carbonization process for C/H/O/N-Based polymers with the ReaxFF reactive force field, J. Phys. Chem. B, 123 (2019) 5357-5367.

10.1021/acs.jpcb.9b04298

A. M. Kamat, A. C. T. van Duin, A. Yakovlev, Molecular Dynamics Simulations of Laser-Induced Incandescence of Soot Using an Extended ReaxFF Reactive Force Field, J. Phys. Chem. A, 114 (2010) 12561-12572.

10.1021/jp1080302

P. Nageswara Rao, D. Kunzru, Thermal cracking of JP-10: Kinetics and product distrubution, J. Anal. Appl. Pyrolysis, 76 (2006) 154-160.

10.1016/j.jaap.2005.10.003

Y. Liu, R. Chen, J. Liu, X. Zhang, Research progress of catalysts and initiators for promoting the cracking of endothermic hydrocarbon fuels, Trans. Tianjin Univ., 28(3) (2022) 199-213.

10.1007/s12209-022-00315-0

D. Sun, C. Li, Y. Du, L. Kou, J. Zhang, Y. Li, Z. Wang, J. Li, H. Feng, J. Lu, Effects of endothermic hydrocarbon fuel composition on the pyrolysis and anticoking performance under supercritical conditions, Fuel, 239 (2019) 659-666.

10.1016/j.fuel.2018.11.003

D. Wickham, G. Alptekin, J. Engel, M. Karpuk, Additives to reduce coking in endothermic heat exchangers, In 35th Joint Propulsion Conference and Exhibit, (1999) 2215.

10.2514/6.1999-2215

R. Edina, B. Bela, F. Bela, Formation and growth mechanisms of polycyclic aromatic hydrocarbons: A mini-review, Chemosphere, 291 (2022) 132793.

10.1016/j.chemosphere.2021.132793

H. Liu, J. Liang, R. He, X. Li, M. Zheng, C. Ren, G. An, X. Xu, Z. Zheng, Overall mechanism of JP-10 pyrolysis unraveled by large-scale reactive molecular dynamics simulation, Combust. Flame, 237 (2022) 111865.

10.1016/j.combustflame.2021.111865

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 :1
Pages :57-66
Received Date : 2025-02-07
Revised Date : 2025-02-14
Accepted Date : 2025-02-14
DOI :https://doi.org/10.15231/jksc.2025.30.1.057

Journal of the Korean Society of Combustion ISSN:1226-0959(Print) 2466-2089(Online) 한국연소학회지

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