Thermodynamic and economic assessment of a solar-assisted ORC-hydrogen system for natural gas pressure energy recovery

Abstract

A significant amount of pressure energy is wasted during natural gas pressure reduction, while the cold energy generated from expansion is utilized inefficiently and typically relies on fossil fuel combustion for reheating. To address these challenges, this study proposes a pressure energy recovery system designated Int-ORC that combines an Organic Rankine Cycle, photovoltaic power generation, and alkaline water electrolysis for hydrogen production. Based on actual operational data from a pressure reduction station in Inner Mongolia, China, a coupled thermodynamic and economic model was developed using MATLAB to evaluate system performance. The Int-ORC system is compared against a basic pressure energy recovery system designated Ref. A and a pressure energy recovery system with hydrogen production designated Ref. B. The results show that the Int-ORC system achieves primary energy saving rates of 3.81 in summer and 2.98 in winter, representing improvements of 0.14 and 0.81 over Ref. A and Ref. B, respectively. The cold energy is fully utilized, achieving zero fossil fuel consumption. Hydrogen production rates reach 18.41 m3/h in summer and 18.78 m3/h in winter, both outperforming Ref. B. This study provides a technical foundation for the construction of next-generation gas stations integrating power generation, hydrogen production, and hydrogen blending functionalities.

Keywords

Natural gas pressure energy recovery / Organic Rankine Cycle / Cold energy utilization / Thermo-economic assessment

CRediT authorship contribution statement

Jianan Feng: Writing – original draft, Validation, Software. Ran Tian: Writing – review & editing, Project administration, Methodology. Hongjian Wang: Conceptualization. Xiaorui Zhang: Supervision. Deqiang Wang: Formal analysis. Jian Wang: Project administration. Xiao Hu: Formal analysis. Jundi He: Supervision.

Declaration of competing interest

The authors declare the following financial interests/personal relationships which may be considered as competing interests: Hongjian Wang, Xiaorui Zhang, Deqiang Wang, Jian Wang and Xiao Hu are currently employed by their respective companies. No additional financial support was received from their employers for the work reported in this paper. All other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgement

This work is supported by the Science and Technology Program of Inner Mongolia Autonomous Region (Grant No. 2023YFHH0032).

References

[1] Andrei, I., Tudorache, V., Cristina, T., Niculae, T., 2014. Recovery of wasted mechanical energy from the reduction of natural gas pressure. Procedia Eng. 69, 986-990. https://doi.org/10.1016/j.proeng.2014.03.080.

[2] Aryanfar, Y., Mohtaram, S., García Alcaraz, J.L., Sun, H., 2023. Energy and exergy assessment and a competitive study of a two-stage ORC for recovering SFGC waste heat and LNG cold energy. Energy 264, 126191. https://doi.org/10.1016/j.energy.2022.126191.

[3] Bielka, P., Kuczyński, S ., 2022. Energy recovery from natural gas pressure reduction stations with the use of turboexpanders: static and dynamic simulations. Energies 15, 8890. https://doi.org/10.3390/en15238890.

[4] BP, 2014. Home | statistical review of world energy. https://www.energyinst.org/statistical-review. (Accessed 23 March 2026).

[5] Cui, Y., Liu, J., 2025. Performance analysis of natural gas pressure energy utilization system based on gas turbine combined cycle power plant. J. Phys., Conf. Ser. 3018, 012015. https://doi.org/10.1088/1742-6596/3018/1/012015.

[6] Dyreby, J.J., 2014. Modeling the Supercritical Carbon Dioxide Brayton Cycle with Recompression. Dissertations & Theses - Gradworks.

[7] Hou, Z., Luo, J., Cao, C., Ding, G., 2023. Development and contribution of natural gas industry under the goal of carbon neutrality in China. Advanced Engineering Sciences 55, 243-252. https://doi.org/10.15961/j.jsuese.202200226.

[8] Isaac, T., 2019. HyDeploy: the UK's first hydrogen blending deployment project. Clean 3, 114-125. https://doi.org/10.1093/ce/zkz006.

[9] Jia, X.F., 2024. Research progress on hydrogen embrittlement behavior of pipeline steel for hydrogen-blended natural gas transportation. Corrosion Protect 45, 88-96.

[10] Jie, P.F., Jin, X.W., Liu, J.Y., et al. , 2024. Economic cost, energy consumption and CO₂ emission analysis of photovoltaic power generation equipment in China. Heat. Vent. Air Cond. 54, 151-156. https://doi.org/10.19991/j.hvac1971.2024.08.20.

[11] Khanmohammadi, S., Ahmadi, P., Atashkari, K., Kamali, R.K., 2015. Design and optimization of an integrated system to recover energy from a gas pressure reduction station. In: Dincer, I., Colpan, C.O., Kizilkan, O., Ezan, M.A. (Eds.), Progress in Clean Energy, vol. 1. Springer International Publishing, Cham, pp. 89-107. Analysis and Modeling.

[12] Kim, H., You, H., Choi, K.-S., Han, S., 2020. A study on interconnecting to the power grid of new energy using the natural gas pressure. J. Electr. Eng. Technol. 15, 307-314. https://doi.org/10.1007/s42835-019-00324-5.

[13] Kostowski, W.J., Usón, S., 2013. Comparative evaluation of a natural gas expansion plant integrated with an IC engine and an organic Rankine cycle. Energy Convers. Manag. 75, 509-516. https://doi.org/10.1016/j.enconman.2013.06.041.

[14] Le, S., Lee, J.-Y., Chen, C.-L., 2018. Waste cold energy recovery from liquefied natural gas (LNG) regasification including pressure and thermal energy. Energy 152, 770-787. https://doi.org/10.1016/j.energy.2018.03.076.

[15] Moghaddas-Zadeh, N., Farzaneh-Gord, M., Ebrahimi-Moghadam, A., Bahnfleth, W.P., 2023. Techno-economic assessment of a proposed novel hybrid system for natural gas pressure reduction stations. Process Saf. Environ. Prot. 178, 905-918. https://doi.org/10.1016/j.psep.2023.08.082.

[16] Oosthuizen, P., 2011. An investigation of the performance of a hybrid turboexpander-fuel cell system for power recovery at natural gas pressure reduction stations. Appl. Therm. Eng. https://doi.org/10.1016/J.APPLTHERMALENG.2011.04.023.

[17] Sanaye, S., Mohammadi, Nasab A., 2012. Modeling and optimizing a CHP system for natural gas pressure reduction plant. Energy 40, 358-369. https://doi.org/10.1016/j.energy.2012.01.060.

[18] Tian, Z., Qi, Z., Gan, W., et al. , 2022. A novel negative carbon-emission, cooling, and power generation system based on combined LNG regasification and waste heat recovery: energy, exergy, economic, environmental (4E) evaluations. Energy 257, 124528. https://doi.org/10.1016/j.energy.2022.124528.

[19] Ting, Y., Zhen, P., Zhenbo, L., et al. , 2025. Design, analysis, and multi-objective optimization of LNG cold energy cascade utilization CCHP system including ORC, cold storage, and data center cooling. Cryogenics 150, 104152. https://doi.org/10.1016/j.cryogenics.2025.104152.

[20] Turton, R. (Ed.), 2012. Analysis, Synthesis, and Design of Chemical Processes, fourth ed. Prentice Hall, Upper Saddle River, NJ.

[21] Wang, N., Niu, W., Zhang, T., 2026. Research on integrated energy system optimal operation considering electrolyzer dynamic operation and lifetime degradation. Sustainability 18. https://doi.org/10.3390/su18073423.

[22] Wei, J.D., Li, Z.D., Zhu, Y.R., et al. , 2021. Research progress of natural gas expansion pressure differential power generation for waste energy recovery. Chemical Machinery 48, 644-647.

[23] Xiong, Y.Q., Hua, B., Luo, D.X., Xu, W.D., 2007. Refrigeration device for waste rubber crushing using pressure energy of natural gas pipeline network. Mod. Chem. Ind. 49-52. https://doi.org/10.16606/j.cnki.issn0253-4320.2007.01.012.

[24] Yang, Z.Q., Ma, J.G., Yun, Q., et al. , 2025. Current status and development trend of natural gas pressure differential power generation technology. https://doi.org/10.3969/j.issn.2097-0021.2025.05.015.

[25] Yadav, S., Seethamraju, S., Banerjee, R., 2023. Cold energy recovery from liquefied natural gas regasification process for data centre cooling and power generation. Energy 283, 128481. https://doi.org/10.1016/j.energy.2023.128481.

[26] Yu, H., Kim, D., Gundersen, T., 2019. A study of working fluids for organic rankine cycles (ORCs) operating across and below ambient temperature to utilize liquefied natural gas (LNG) cold energy. Energy 167, 730-739. https://doi.org/10.1016/j.energy.2018.11.021.

[27] Zhao, H., Lu, R., Zhang, T., 2023. Thermodynamic and economic performance study of SOFC combined cycle system using biomass and LNG coupled with CO₂ recovery. Energy Convers. Manag. 280, 116817. https://doi.org/10.1016/j.enconman.2023.116817.

[28] Zhou, X., Li, S. H.,Wang, H., et al. , 2023. Modeling and simulation of photovoltaic coupled water electrolysis hydrogen production system. Southern Energy Construction 10, 104-111. https://doi.org/10.16516/j.gedi.issn2095-8676.2023.03.011.

[29] Zhu, L.Y., Xiong, B., Wang, Z.J., et al. , 2021. Application of natural gas pressure differential power generation technology in underground gas storage. Nat. Gas. Ind. 41, 142-146. https://doi.org/10.3787/j.issn.1000-0976.2021.03.017.