Optimal operation of the boil-off gas compression process using a boil-off rate model for LNG storage tanks

Myung Wook Shin; Dongil Shin; Soo Hyoung Choi; En Sup Yoon

Korean Journal of Chemical Engineering, Vol.25, No.1, 7-12, January, 2008

DOI10.1007/s11814-008-0002-9 Export Citation

Optimal operation of the boil-off gas compression process using a boil-off rate model for LNG storage tanks

Myung Wook Shin, Dongil Shin¹, Soo Hyoung Choi², and En Sup Yoon^†

School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742, Korea
¹Department of Chemical Engineering, Myongji University, Gyeonggi 449-728, Korea
²Division of Environmental and Chemical Engineering, Chonbuk National University, Jeonju 561-756, Korea

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Proper handling of boil-off gas (BOG) significantly affects the operational efficiency as well as the safety of the whole LNG gasification plant. Due to the not well-known inherent dynamics, it has been suspected that the BOG compressors are being operated at too much capacity, unnecessarily consuming too much energy. An empirical model is proposed for the estimation of the boil-off rate (BOR) in an LNG storage tank, based on the specification supplied by the LNG storage tank manufacturer. By using the BOR model, an optimal operation algorithm is proposed for a safe and energy-saving BOG compressor operation, which minimizes the power consumption while preparing against the potential failure of one of the operating compressors. Case study results indicate that the energy consumption could be reduced by a half of the conventional method, by increasing the tank pressure while the safety is maintained. The proposed method is expected to be able to contribute to improving the efficiency of the whole gasification plant operation and control without tempering the safety requirements.

Keywords:LNG Gasification Process;Boil-off Gas;Compressors;Dynamic Modeling and Optimization;Energy-saving Operation

[References]

Doyer H, Gabillard M, Le Cloirec A, Uznanski D, Proc. of the International Gas Research Conference, 2, 744 (1998)
Parfomak PW, Flynn AM, Liquefied natural gas (LNG) import terminals: Siting, safety and regulation, terminals: Siting, safety and regulation, RL32205 (2004)
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Tarlowski J, Sheffield J, Durr C, Coyle D, Patel H, LNG import terminals - Recent developments, www.cheresources.com
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Fukuda K, Okamoto K, Fukui E, Nishitani H, Comput. Chem. Eng., 13(11/12), 1299 (1989)
Shin MW, Shin D, Choi SH, Yoon ES, Submitted to Industrial and Engineering Chemistry Research (2006)
Contreras J, Ferrer JM, Hydrocarbon Engineering, May, 69-72 (2005)
Bates S, Morrison DS, Int. J. Heat Mass Transf., 40(8), 1875 (1997)
Chen QS, Wegrzyn J, Prasad V, Cryogenics, 44, 701 (2004)
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Uznanski D, Versluijs P, LNG Review, 1-7 (2005)

[Referenced By]

[Related Articles]

[1] Doyer H, Gabillard M, Le Cloirec A, Uznanski D, Proc. of the International Gas Research Conference, 2, 744 (1998)

[2] Parfomak PW, Flynn AM, Liquefied natural gas (LNG) import terminals: Siting, safety and regulation, terminals: Siting, safety and regulation, RL32205 (2004)

[3] BP. Statistical Review of World Energy (2005)

[4] Tarlowski J, Sheffield J, Durr C, Coyle D, Patel H, LNG import terminals - Recent developments, www.cheresources.com

[5] Wardell S, LNG Review, 18-20 (2005)

[6] Fukuda K, Okamoto K, Fukui E, Nishitani H, Comput. Chem. Eng., 13(11/12), 1299 (1989)

[7] Shin MW, Shin D, Choi SH, Yoon ES, Submitted to Industrial and Engineering Chemistry Research (2006)

[8] Contreras J, Ferrer JM, Hydrocarbon Engineering, May, 69-72 (2005)

[9] Bates S, Morrison DS, Int. J. Heat Mass Transf., 40(8), 1875 (1997)

[10] Chen QS, Wegrzyn J, Prasad V, Cryogenics, 44, 701 (2004)

[11] Kirishnaswami P, Chapman K, Abbaspour M, Gas Machinery Research Council Technical Papers (2004)

[12] Abbaspour M, Chapman K, Kirishnaswami P, J. Energy Resour., 127(2), 131 (2005)

[13] Uznanski D, Versluijs P, LNG Review, 1-7 (2005)