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INTRODUCTION METHODOLOGY Incorporation of LNG via FSRUs into natural gas networks Devasanthini Devaraj ([email protected]), Philip Donnellan ([email protected]), Eoin Syron ([email protected]) University College Dublin RESULTS C ONCLUSIONS A CKNOWLEDGEMENT This publication has emanated from research conducted with the financial support of Science Foundation Ireland under the SFI Strategic Partnership Programme Grant Number SFI/15/SPP/E3125. The opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the Science Foundation Ireland. Objectives Ireland has a small gas network (13,400 kms) with increasing demand for natural gas (5 bcm, 2017). Recent Floating Storage and Regasification Unit (FSRU) vessels have a capacity of 170,000 m 3 and a gas send out rate of 600 mmscfd which could supply the nation’s demand (averaging 400 mmscfd in July,2018). Establishment of LNG terminal with FSRU offers flexibility in relocation and investment. • To investigate the implications of Long-term storage in FSRUs, thereby to determine the change in boil-off rate (BOR) and analyze the LNG weathering. • To identify the possibility of handling the Boil- off Gas (BOG) generated by operating the regasification unit at a minimum capacity. • To investigate the implications of continuous operation of the FSRU regasification unit and handling the excess supply. • To provide an economic estimate of the FSRU deployment. • LNG supply via FSRU will increase the gas flows in the networks. • Development of small scale LNG networks (ssLNG). • Reduction in carbon neutrality can be achieved by implementing more greener fuels like biomethane with LNG in the energy mix. Scenario Total Production Cost (€mm/year) Final Cost per Unit (cent/kWh) Every 5 Weeks 120.50 1.1931 Every 10 weeks 115.55 2.2881 Every 5 Weeks - 2 IPs 191.98 0.9052 Every 10 Weeks - 2 IPs 181.10 1.7931 A model is developed to determine the BOG generated [1] . REFERENCES [1] Velisa Vesovic Calogero Migliore Cristina Tubilleja. \Weathering predictionmodel for stored liqueed natural gas (LNG)". In: Journal of Natural Gas Science and Engineering (2015). [2] Det Norske Veritas George G. Dimopoulos. \A Dynamic Model for Liqueed Natural Gas Evaporation during Marine Transportation". In: International Journal of Thermodynamics (2008). [3] Brian Songhurst. \The Outlook for Floating Storage and Regasication Units (FSRUs)". In:(2017). • Increase in BOR throughout storage period (up to 0.143% per day) is observed. • In general, Wobbe Index of LNG and BOG are within the operational limits (expect the BOG from LNG with high N 2 ). • Storage up to 5 weeks is identified as the economically attractive option. Fig 1 – Boil-off rate in FSRU storage unit over 10 weeks Fig 2 – Availability of gas for reverse flow at Moffat Fig 3 – Change in Wobbe Index of LNG & BOG over the storage period Table 1 – FSRU Storage implementation: Overall Production Cost & Unit Price of Gas Overall Heat Transfer Coefficient U Latent Heat of Vaporisation: Heat Ingress Q into the Storage Tank Initial Boil-off Rate of LNG Calculate the new Q (due to LNG loss) entering the unit Repeat the above calculation to obtain a BOR trend Simulation of FSRU Storage Tank in Aspen HYSYS: LNG Weathering Economic Estimate for FSRU Storage implementation: 1 or more injection points (IPs) 0.120 0.125 0.130 0.135 0.140 0.145 0 1 2 3 4 5 6 7 8 9 10 Boil off rate (%) Weeks 0 10 20 30 40 50 60 70 25-Jul 26-Jul 27-Jul 28-Jul 29-Jul 30-Jul Natural Gas GWh Days of Month 42 44 46 48 50 52 54 Initial WI 5 Weeks 10 Weeks Initial WI 5 Weeks 10 Weeks LNG BOG WI (MJ/Nm3) WI Change GSMR Lower Limit GSMR Upper Limit
Transcript of University College Dublin - ESIPP
INTRODUCTION
METHODOLOGY
Incorporation of LNG via FSRUs into natural gas networks
Devasanthini Devaraj ([email protected]), Philip Donnellan ([email protected]), Eoin Syron ([email protected])
University College Dublin
RESULTS
CONCLUSIONS
ACKNOWLEDGEMENTThis publication has emanated from research conducted with the financial support of Science Foundation Ireland under the SFI Strategic Partnership Programme Grant Number SFI/15/SPP/E3125. The opinions, findings and conclusions or recommendations expressed in this material are thoseof the author(s) and do not necessarily reflect the views of the Science Foundation Ireland.
Objectives
Ireland has a small gas network (13,400 kms) withincreasing demand for natural gas (5 bcm, 2017).Recent Floating Storage and Regasification Unit(FSRU) vessels have a capacity of 170,000 m3 anda gas send out rate of 600 mmscfd which couldsupply the nation’s demand (averaging 400mmscfd in July,2018). Establishment of LNGterminal with FSRU offers flexibility in relocationand investment.
• To investigate the implications of Long-termstorage in FSRUs, thereby to determine thechange in boil-off rate (BOR) and analyze theLNG weathering.
• To identify the possibility of handling the Boil-off Gas (BOG) generated by operating theregasification unit at a minimum capacity.
• To investigate the implications of continuousoperation of the FSRU regasification unit andhandling the excess supply.
• To provide an economic estimate of the FSRUdeployment.
• LNG supply via FSRU will increase the gas flows in the networks.• Development of small scale LNG networks (ssLNG).• Reduction in carbon neutrality can be achieved by implementing more greener fuels like
biomethane with LNG in the energy mix.
ScenarioTotal Production Cost
(€mm/year)Final Cost per Unit
(cent/kWh)
Every 5 Weeks 120.50 1.1931
Every 10 weeks 115.55 2.2881
Every 5 Weeks - 2 IPs 191.98 0.9052
Every 10 Weeks - 2 IPs 181.10 1.7931
A model is developed to determine the BOGgenerated[1].
REFERENCES[1] Velisa Vesovic Calogero Migliore Cristina Tubilleja. \Weathering prediction model for stored liqueed natural gas (LNG)". In: Journal ofNatural Gas Science and Engineering (2015).[2] Det Norske Veritas George G. Dimopoulos. \A Dynamic Model for Liqueed Natural Gas Evaporation during Marine Transportation". In:International Journal of Thermodynamics (2008).[3] Brian Songhurst. \The Outlook for Floating Storage and Regasication Units (FSRUs)". In:(2017).
• Increase in BOR throughout storage period (up to 0.143% per day) is observed.• In general, Wobbe Index of LNG and BOG are within the operational limits (expect the
BOG from LNG with high N2).• Storage up to 5 weeks is identified as the economically attractive option.
Fig 1 – Boil-off rate in FSRU storage unit over 10 weeks Fig 2 – Availability of gas for reverse flow at Moffat
Fig 3 – Change in Wobbe Index of LNG & BOG over the storage period
Table 1 – FSRU Storage implementation: Overall Production Cost & Unit Price of Gas
Overall Heat Transfer Coefficient U
Latent Heat of Vaporisation: Heat Ingress Q into the Storage Tank
Initial Boil-off Rate of LNG
Calculate the new Q (due to LNG loss) entering the unit
Repeat the above calculation to obtain a BOR trend
Simulation of FSRU Storage Tank in Aspen HYSYS: LNG Weathering
Economic Estimate for FSRU Storage implementation: 1 or more injection points (IPs)
0.120
0.125
0.130
0.135
0.140
0.145
0 1 2 3 4 5 6 7 8 9 10
Bo
il o
ff r
ate
(%)
Weeks
0
10
20
30
40
50
60
70
25-Jul 26-Jul 27-Jul 28-Jul 29-Jul 30-Jul
Nat
ura
l Gas
GW
h
Days of Month
42
44
46
48
50
52
54
Initial WI 5 Weeks 10 Weeks Initial WI 5 Weeks 10 Weeks
LNG BOG
WI (
MJ/
Nm
3)
WI Change GSMR Lower Limit GSMR Upper Limit
