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Process Analysis and Simulation for System of Air Liquefaction Separation Using LNG Cold Energy

LNG 냉열을 이용한 공기액화분리시스템의 시뮬레이션 및 공정 해석

  • HAN, DANBEE (Department of Environment and Energy Engineering, The University of Suwon) ;
  • BAEK, YOUNGSOON (Department of Environment and Energy Engineering, The University of Suwon)
  • 한단비 (수원대학교 환경에너지공학과) ;
  • 백영순 (수원대학교 환경에너지공학과)
  • Received : 2019.05.30
  • Accepted : 2019.06.30
  • Published : 2019.06.30

Abstract

The process of separating oxygen and nitrogen from the air is mainly performed by electric liquefaction, which consumes a lot of electricity, resulting in higher operating costs. On the other hand, when used for cold energy of LNG, electric power can be reduced compared to the electric Linde cycle. Currently, LNG cold energy is used in the cold refrigeration warehouse, separation of air-liquefaction, and LNG cold energy generation in Japan. In this study, the system using LNG cold energy and the Linde cycle process system were simulated by PRO/II simulators, respectively, to cool the elevated air temperature from the compressor to about $-183^{\circ}C$ in the air liquefaction separation process. The required amount of electricity was compared with the latent heat utilization fraction of LNG, the LNG supply pressure, and the LNG cold energy usage. At the air flow rate of $17,600m^3/h$, the power source unit of the Linde cycle system was $0.77kWh/m^3$, compared with $0.3kWh/m^3$.

Keywords

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Fig. 1. Refrigeration cycle for Linde process

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Fig. 3. The simulation model for air liquefaction separation process

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Fig. 2. Air liquefaction separation process for Linde cycle

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Fig. 4. Required LNG amount for E1 with vapor fraction

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Fig. 5. LNG latent heat with LNG supply pressure

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Fig. 6. Required LNG amount for E1 and E3 with LNG supply press.

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Fig. 7. The amount of replaced electric power with LNG cold en-ergy

Table 1. The status of air liquefaction separation process using LNG cold energy8)

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Table 2. Air liquefaction separation system for Linde cycle and using LNG cold energy

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Table 3. Required energy of main equipments for process

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Table 4. Power unit price (kWh/m3) for air liquefaction separa-tion process using LNG cold energy

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References

  1. B. B. Kanbur, L. Xiang, S. Dubey, F. H. Choo, and F. Duan, "Cold utilization system of LNG: A review", Renwable and Sustainable Energy Reviews, Vol. 79, 2017, pp. 1171-1188, doi: http://dx.doi.org/10.1016/j.rser.2017.05.161.
  2. A. Messineo and D. Panno, "Potential applications using LNG cold energy in Sicily", International Journal of Energy Res, Vol. 32, No. 11, 2008, pp. 1058-1064, doi: https://doi.org/10.1002/er.1411.
  3. S. Hirakawa and K. Kosugi, "Utilization of LNG cold: Utilisation du froid du GNL", International Journal of Refrigeration, Vol. 4, No. 1, 1981, pp. 17-21, doi: https://doi.org/10.1016/0140-7007(81)90076-1.
  4. N. Zhang and N. Lior, "Novel near-zero $CO_2$ emission thermal cycle with LNG cryogenic exergy utilization", Energy, Vol. 31, No. 10-11, 2006, pp. 1666-1679, doi: https://doi.org/10.1016/j.energy.2005.05.006.
  5. K. Jiang, "Economic analysis of LNG cold energy utilization", Springer, Switzerland, 2017, pp. 119-132, doi: https://doi.org/10.1007/978-3-319-26950-4_5.
  6. M. Kundu, "Simulation of air liquefaction using aspen plus", National Institute of Technology Rourkela, India, 2012. Retrieved from ethesis.nitrkl.ac.in/3235/.
  7. M. Mehrpooya, M. Sharifzadeh, and M. Chahartaghi, "Investigation of novel Intergrated air separation processes, cold exergy recovery of liquefied natural gas and carbon dioxide power cycle", Journal of Cleaner Production, Vol. 113, 2016, pp. 411-425, doi: http://dx.doi.org/10.1016/j.jclepro.2015.12.058.
  8. "A study on the power generation technology utilizing LNG cold energy", Report, KOPEC R&D Institute, Korea, 1985, pp. 941-956.
  9. R. F. Barron, "Cryogenic system", Oxford University Press, New York, 1985
  10. Y. Q. Xiong and B. Hua, "Simulation and analysis of the air separation process by using cold energy", China Academic Journal Electric Publishing House, Vol. 25, No. 3, 2007, pp. 68-76. Retrieved from http://www.airitilibrary.com/Publication/alDetailedMesh?docid=10005811-200706-25-3-68-72-a.
  11. D. Han, Y. Kim, K. Yeom, J. Shin, and Y. Baek, "A sttudy of simulation on the Refrigerated warehouse system based on the cold energy of LNG using the PRO-II simulator", Trans. of the Korean Hydrogen and New Energy Society, Vol. 28, No. 4, 2017, pp. 401-406, doi: https://doi.org/10.7316/KHNES.2017.28.4.401.