Incorporation of LNG into Small Gas Networks via FSRUs

Incorporation of LNG into Small Gas Networks via FSRUs

Devasanthini Devaraj Philip Donnellan Eoin Syron

School of Chemical & Bioprocess Engineering, University College Dublin, Ireland

UCD Energy Institute, University College Dublin, Ireland

Page: 
53-62
|
DOI: 
https://doi.org/10.2495/EQ-V4-N1-53-62
Received: 
N/A
| |
Accepted: 
N/A
| | Citation

OPEN ACCESS

Abstract: 

Geopolitical risks on pipeline gas imports, increasing natural gas demand and the need to ensure continuous power supply with ever increasing fluctuating renewable power generation require diversification of gas sources to ensure supply security. With the global liquefied natural gas (LNG) trade increasing every year and natural gas prices remaining relatively low, more and more countries are interested in investing in regasification infrastructure. Establishing a floating storage and regasification unit (FSRU) and importing LNG has several advantages: lower cost compared to an onshore terminal, flexibility in relocation and the availability of short-term contracts all of which help serve small markets. FSRUs can also be operated in standby mode or used as an LNG storage facility. Operating an FSRU as a storage facility while beneficial for small networks introduces the challenges of LNG weathering and managing of the boil-off gas (BOG). To investigate these challenges on operation, a mathematical model is developed to determine the boil-off rate (BOr) over various time frames. The initial BOr is 0.129% of the initial storage volume increased to 0.143% after 10 weeks. Subsequent use of aspen hySyS to determine the change in LNG composition determined that Wobbe Index (WI) of the LNG varied from 51.58 to 51.616 mj/Nm3 after 10 weeks of storage. an annual economic estimation of operating FSRU as a storage facility was carried out determining that the per unit price of gas obtained from regasified LNG is at least 42% lower than the current per unit price of gas in Ireland.

Keywords: 

boil-off rate, FSRU, LNG storage, LNG weathering

  References

[1] International Gas Union. IGU 2018 world LNG report, September 2018. https://www. igu.org/sites/default/files/node-document-field_file/IGU_LNG_2018_0.pdf (accessed 18 february 2019).

[2] International Gas Union. IGU 2017 world LNG report, 2017. https://www.igu.org/ sites/default/files/103419-World_IGU_report_no%20crops.pdf (accessed 18 february 2019).

[3] International Gas Union. IGU 2015 world LNG report, 2015. https://www.igu.org/sites/ default/files/node-page-field_file/IGU-World%20LNG%20report-2015%20Edition. pdf (accessed 18 february 2019).

[4] Songhurst, B., The Outlook for Floating Storage and Regasification Units (FSRUs). Oxford Institute for Energy Studies, july 2017.

[5] Excelerate  Energy.  Excelerate  energy  fSrU  fleet,  2018.  http://excelerateenergy.com (accessed 18 february 2019).

[6] Wood, k., Gomes, I., ho, B., kerr, S., cavanagh, S., Wood, D. & haywood, a.,

Guidebook to Gas Interchangeability and Gas Quality. BP/IGU, august 2011.

[7] Ervia and Gas Networks Ireland. A Look at the Irish Gas Market. Gas Networks Ireland, 2018.

[8] Brouwer, j., mac kinnon m.a. & Samuelsen S., The role of natural gas and its infra- structure in mitigating greenhouse gas emissions, improving regional air quality, and renewable resource integration. Progress in Energy  and  Combustion  Science,  64, pp. 62–92, january 2018. https://doi.org/10.1016/j.pecs.2017.10.002

[9] Sustainable Energy authority of Ireland (SEaI). Energy statistics: Primary energy supply (mtoe)—natural gas (1990-2030), 2018. https://www.seai.ie/resources/publica- tions/commercial-fuel-cost-comparison.pdf (accessed 18 february 2019).

[10] Ervia and Gas Networks Ireland. Transportation network monthly report, 2018. https://www.gasnetworks.ie/corporate/gas-regulation/transparency-and-publicat/2018- reports/ (accessed 18 febraury 2019).

[11] migliore, c., Tubilleja, c. & Vesovic, V., Weathering prediction model for stored liquefied natural gas (LNG). Journal of Natural Gas Science and Engineering, 26,  pp. 570–580, September 2015. https://doi.org/10.1016/j.jngse.2015.06.056

[12] Dimopoulos, G.G. & frangopoulos, c.a., a dynamic model for liquefied natural gas evaporation during marine transportation. International Journal of Thermodynamics, 11(3), pp. 123–131, September 2008.

[13] Dobrota, D., Lali ć , B. & komar, I., Problem of boil - off in LNG supply chain. Transactions on Maritime Science, 2(2), pp. 91–100, October 2013. https://doi. org/10.7225/toms.v02.n02.001

[14] European commission. Technical information on projects of common interest, april 2018. https://ec.europa.eu/energy/sites/ener/files/technical_document_3rd_list_with_ subheadings.pdf (accessed 18 february 2019).

[15] SEaI. commercial / industrial fuels: comparison of energy costs, October 2018. https://www.seai.ie/resources/energy-data/ (accessed 18 february 2019).

[16] Trevor Sikorski. Energy aspects. LNG regas costs: fixed or variable? September 2017. https://www.energyaspects.com/publications/view/2017-09-06-natural-gas-natural- gas-global-lng-lng-regas-costs-fixed-or-variable (accessed 04 march 2019).

[17] Trevor Sikorski. Energy aspects. LNG regas costs: fixed or variable? april 2017. https://www.energyaspects.com/publications/view/2017-04-24-natural-gas-natural- gas-global-lng-insight-lng-transport-fixed-or-variable (accessed 04 march 2019).

[18] U.S. Energy Information administration (EIa). annual Energy Outlook 2019 with projections to 2050, january 2019. https://www.eia.gov/outlooks/aeo/pdf/aeo2019.pdf (accessed 04 march 2019).