”hydratproduksjon” lagring og transport av naturgass prof. jón steinar guðmundsson ntnu nfr,...
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””HYDRATPRODUKSJON”HYDRATPRODUKSJON”Lagring og transport av naturgassLagring og transport av naturgass
Prof. Jón Steinar Guðmundsson
NTNU
NFR, Olje og gass programseminar
Stavanger, 3.-4. april 2003
NGH R&D at NTNUNGH R&D at NTNU Phase Ia (1990-1991). Early work funded by the SPUNG program
of the Research Council of Norway. Phase Ib (1991-1993). Continued early work funded by Statoil’s
Research Center in Trondheim. Phase Ic (1993-1996). Laboratory and process design work
funded by Aker Engineering. Phase IIa (1997-1999). Joint Industry Project funded by Aker
Engineering and six international oil companies and the Research Council of Norway.
Phase IIb (1999-2002). Doctoral project funded by the Research Council of Norway.
Phase III (2002…). NTNU + Aker Kværner Technology, special projects and international co-operation.
Hydrate Hydrate EEquilibrium quilibrium CCurveurve
0
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0 5 10 15 20 25
Temperature [°C]
Pre
ss
ure
[b
ar]
Natural gas
Methane
0
20
40
60
80
100
120
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180
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0 5 10 15 20 25
Temperature [°C]
Pre
ss
ure
[b
ar]
Natural gas
Methane
180 Sm3 of gas
1 m3 of hydrate
Production of HydratesProduction of HydratesIndustrial ProcessIndustrial Process
Natural Gas Freezing
unit
Separator
unit
Reactor
unit
Water
Slurry Hydrate
Water
Frozen Hydrate
Hydrate LaboratoryHydrate Laboratory
Hydrate LaboratoryHydrate Laboratory
Hydrate Dr.Ing. Theses at NTNUHydrate Dr.Ing. Theses at NTNUDepartment of Petroleum Engineering and Applied GeophysicsDepartment of Petroleum Engineering and Applied Geophysics
Aftab A. Khokhar 1998: Storage properties of natural gas hydrates
Vibeke Andersson 1999: Flow properties of natural gas hydrate slurries
Odd Ivar Levik 2000: Thermophysical and compositional properties of natural gas hydrates
Marit Mork 2002: Formation rate of natural gas hydrate
NTNU’s Hydrate LaboratoryNTNU’s Hydrate Laboratory9.5 litre continuous stirred tank reactor9.5 litre continuous stirred tank reactor
Results –experimental conditionsResults –experimental conditions
Steady-state operation Methane and natural gas
mixture (92% C1, 5% C2, 3% C3)
Gas injection rate 27–339 Nl/min
Subcooling 2.1-5.6 °C Stirring rate 400, 800 RPM
0
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120
0 5 10 15 20 25
Temperature (°C)
Pre
ss
ure
(b
ar)
Natural gas mixture
Methane gas
Results –effect of gas Results –effect of gas compositioncompositionPressure 70 bar, subcooling 3 °C, stirring rate Pressure 70 bar, subcooling 3 °C, stirring rate 400 RPM400 RPM
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0 50 100 150 200 250 300Gas injection rate (Nl/min)
Gas
co
nsu
mp
tio
n r
ate
(Nl/m
in)
methane gas
natural gas mixture
BackgroundLab and procedure
Experimental resultsMass transfer model
Production of hydratesConclusions
NGH CrystalsNGH Crystals2670x Magnification2670x Magnification
20 m 20 m
Summary experimental resultsSummary experimental resultsRate of hydrate formationRate of hydrate formation
Proportional to gas injection rate
Highly influenced by pressure
Less influenced by stirring rate
Not influenced by gas composition
Not influenced by subcooling
Not influenced by crystal concentration
Rate of hydrate formation is gas-liquid mass transfer limited
Mass transfer modelMass transfer modelConceptConcept
CbGas bubble
liquid water
Hydrate crystalCb
Csol
Ceq
Tg
Gas bubbleHydrate crystal
TeqTbTb
Tsol
kL kS
BackgroundLab and procedure
Experimental resultsMass transfer model
Production of hydratesConclusions
Model and experimental dataModel and experimental data
tot sol eq
gsg
0.18011.124g
tot sg sol eq
R K (C C ) V
PK v
V
PR 363.3 v C C 9.5
V
0
50
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150
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0 100 200 300 400Gas injection rate (Nl/min)
Ga
s c
on
su
mp
tio
n r
ate
(N
l/min
)
70 bar
90 bar
90 bar *
* Parlaktuna and Gudmundsson (1998)
Overall mass transfer coefficient:
Gas consumption rate in CSTR:
Overall rate of hydrate formation for total liquid volume:
Non-Pipeline TechnologiesNon-Pipeline Technologies
CNG Compressed Natural GasGTL Gas-to-Liquid (incl. MOH)GTWGas-to-Wire (DC and AC)LNG Liqufied Natural Gas (GTL?)NGH Natural Gas Hydrate
CAPACITY-DISTANCE DIAGRAM CAPACITY-DISTANCE DIAGRAM Gudmundsson and Mork (2001)Gudmundsson and Mork (2001)
0,1
1,0
10,0
100 1000 10000
Distance (km)
Cap
acit
y (B
CM
/yea
r)
PIPE LNG
CNG, GTW, NGH GTL
ALL
0,1
1,0
10,0
100 1000 10000
Distance (km)
Cap
acit
y (B
CM
/yea
r)
PIPE LNG
CNG, GTW, NGH GTL
ALL
Chain LNG NGH Difference
Production 1144 (55%) 992 (54%) 152(13%)
Carriers 660 (32%) 628 (34%) 32 (5%)
Regasification 285 (13%) 218 (12%) 67 (24%)
Total 2089 (100%) 1838 (100%) 251 (12%)
Capital cost of NGH and LNG chains for 400 MMscfs production and transport over 3243 nautical miles (6000 km). Cooling water
temperature 35 C (5 C in 1996 study). Million US dollars mid-2002 (Aker Kværner Technology AS)
22nd World Gas Conference Tokyo, June 1-5, 2003
HYDRATE NON-PIPELINE TECHNOLOGY FORTRANSPORT OF NATURAL GAS
Jón S. Gudmundsson, Norwegian University of Science and Technology
Oscar F. Graff, Aker Kvaerner Technology AS
SUMMARY
The economics of natural gas transport depends greatly on the annual volumes and transport distances. Pipelines are readily used for distances less than 1000 km and large volumes, while LNG (liquefied natural gas) technology is used for much larger distances. Other non-pipeline technologies are considered suitable for other annual volumes and transport distances. Natural gas hydrate (NGH) technology represents a new non-pipeline technology that is suitable for the transport of small-to-medium annual volumes of natural gas over moderate distances. Surveys of natural gas resources world-wide indicate that about 80% of new discoveries will be smaller than the minimum required to make LNG transport economical (mature technology). Hence the great interest in NGH and similar new technologies. Several groups are developing NGH technology world-wide, including NTNU and Aker Kvaerner Technology in Norway. NGH technology is lower in cost than LNG technology, based on mid-1995 and mid-2002 cost studies for large-scale natural gas chains (NGH will be even more competitive for small-to-medium sized chains). When NGH technology matures its costs are expected to decrease and be even more favourable compared to LNG technology.
ON-GOING R&D PROJECTSON-GOING R&D PROJECTSNTNU, Dept.Pet.Eng., Prof. GudmundssonNTNU, Dept.Pet.Eng., Prof. Gudmundsson
Hydrate Technolog, NTNU + Aker Kværner
Technology AS, NFR stipends
PressurePulse Technology, NTNU +
Markland AS + EU’s SurgeNet
Pressure Loss Reduction Technology, JIP
(Statoil, BP, TFE, GdF, Enagas), NFR
stipend