Gas Hydrates in Energy Recovery, Transportation & Storage

Gas Hydrates in Energy Recovery, Transportation & Storage K.C. Hester, A. Gupta, L.J. Rovetto, H. Ohno, S. Wierzchowski J. Boxall, S. Davies, J. Nich...
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Gas Hydrates in Energy Recovery, Transportation & Storage

K.C. Hester, A. Gupta, L.J. Rovetto, H. Ohno, S. Wierzchowski J. Boxall, S. Davies, J. Nicholas, P. Rensing, T. Strobel, D. Greaves, J. Lachance, M. Walsh L. Dieker, C. Timm, G. Green, A. Hughson, A. Papineau, B. Sikora S.F. Dec, K.T. Miller, E.D. Sloan, Jr. (Director), C.A. Koh (Co-director), Energy Seminar, Stanford University, April 18, 07 Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Outline ƒ What are hydrates? Why are they important? ƒ Controlling hydrate formation/decomposition ƒ Highlights of CHR research • Ocean Raman studies of natural seafloor hydrates • Hydrate decomposition for energy recovery • Hydrogen storage in clathrate hydrates • Hydrates in flow assurance • Molecular tools for hydrate formation/decomposition studies

ƒ Future directions Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

What are Clathrate Hydrates? Hot Stuff!

ƒ Crystalline solids • Like ice ƒ Made of water cages ƒ Traps “guest” molecules • e.g. methane, carbon dioxide

ƒ Concentrate large volumes of gas • ~170 m3 of gas (STP)/m3 hydrate Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Clathrate Hydrate Structures 51262

6/cell

51264

8/cell

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Why Are Hydrates Important?

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Potential Future Energy Resource Current Estimates 1015-1017 m3 Hydrated Gas

Mallik2002 Gas: 468SCM in 125 hrs

GAS

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Economic & Safety Risks of Hydrate Formation in Pipelines

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Safety Models Could Prevent Accidents Pupstream

friction

∆P

Pdownstream

Newton’s Laws of Motion describe the position, velocity & acceleration of the plug

Hydrate Accident

Approach to Control Clathrate Hydrates CSMHyK-OLGA Multiphase Flow Model & Flowloop Data

Sensitivity analysis of kinetic parameters & fluids

Diffraction, Raman, NMR Molecular Simulations, Mechanisms of growth, inhibition, decomposition

Prediction Models for Energy Recovery, Transportation, and Storage Hydrate agglomeration

MMF, PSA, DSC Rheology

Hydrate phases as a function of time

Raman, NMR, Diffraction, DSC, X-ray CT, Visual

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Highlights of CHR Research

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

In situ ocean hydrate measurements

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Ocean Raman Studies of Natural Seafloor Hydrates Keith C. Hester (Ph.D. thesis)

MBARI ROV Tiburon Precision Underwater Positioner

LRS in housing Raman probe

Barkley Canyon Expedition August 10-19, 2006 K.C. Hester, E.D. Sloan (CSM) P.G. Brewer, E.T. Peltzer, P. Walz, R.M. Dunk (MBARI)

(Chapman, (Chapman, 2004) 2004)

Natural hydrate mounds

In Situ Raman Measurement

51262

In situ Ocean Raman spectra of sI methane hydrate 512 methane CH Stretching region

H2O OH Stretch

Coexistence of sI/sII measured in situ SO42-

C2H6, sII

CH4, sI/sII L

CH4, sI/sII S

Intensity (A.U.)

C2H6, sI

C3H8 i-C4H10 *

White hydrate

Raman Shift (cm-1)

*

*

Hydrate cored recovered for laboratory measurements ƒ Both pressurized and non-pressurized ƒ Lab tools • Raman and NMR • X-ray diffraction

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

sII, sH Confirmed by XRD

Yellow hydrate Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Experiments & Simulations of Hydrate Decomposition for Energy Recovery

Density (kg/m3)

Arvind Gupta (Ph.D. thesis) Collaboration with LBNL Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

0.30 0.50 0.70 0.90 1.10

Density (g/cm3)

1.30

Hydrate Plug Decomposition Studies Using CT X-ray Measurements

Coolant

Tedge

Touter Tinner Tcenter

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Density Profile Variation of the Hydrate Plug 1000 Zone 2

Zone 1

Zone 3

(Transition zone)

3

Average Density (kg/m )

800

600

400

200 Expt_ Avg. Density

0 0.0

0.5

1.0

1.5 2.0 2.5 Radial Position (cm)

3.0

3.5

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

H2 Storage in Clathrate Hydrates ƒ Florusse et al. Science (2004): Binary THF-H2 hydrate (CSM & TU Delft) 1000

Pressure reduction 2 orders of magnitude

Pressure (MPa)

Pure H2

100

H2/THF Hydrates Stable H2/THF

10

Pure THF

Hydrates Melt 1 270

275

280

285

290

Temperature (K)

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

295

300

Capillary Tube holds~400 MPa

High P Raman Studies of H2 Hydrates Trends in H-H vibron peaks (Tim Strobel, PhD student)

Free H2, 200 MPa 295 K

Dissolved H2, 200 MPa 295 K

Clathrate, 200 MPa 250 K Raman Shift cm-1 Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Single H2 Occupancy Confirmed in Binary THF sII Hydrate Hester et al. J. Phys. Chem. (2006) Strobel et al. J. Phys. Chem. B (2006)

1a THF-d8 sII hydrate

12

Normalized Intensity

F rac tio n al O cc u p a n c y o f H 2 in 5 12 C ag e

1 H2 / 5 cage

1.0

0.8

0.6 Crushed THF Hydrate 45 microns Crushed THF Hydrate 250 microns Udachin (1994) Best Fit Langmuir Isotherm

0.4

1b D2 + THF-d8 sII hydrate

0.2

0.0 0

100

200 300 Hydrogen Fugacity (MPa)

400

500

D-spacing (Å) DCenter Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

H2 can stabilize sII binary hydrate with cyclohexanone Strobel et al., 2007

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

H2 Occupancy in Binary & Pure H2 Hydrates: 1 H2 in sII 512 Cage & 1-4 H2 in 51264 Cage

Binary CHONE/H2 hydrate 10.0

Pure H2 hydrate

Rwp (%)

Neutron Intensity

9.0 8.0 7.0 6.0 5.0 0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Fractional Occupancy of D2

1.0

2.0

3.0

4.0

5.0

D-spacing (Å)

Strobel et al., 2007

Lokshin et al., 2004

Hester et al., J. Phys.Chem. B, 2006 Strobel et al., J. Phys. Chem. B, 2006 Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Hydrates in Flow Assurance

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

On the Cusp of a Hydrate Change

Avoidance ƒ Avoid Hydrate T&P • Thermodynamics • Time Independent • Within 1.4oF; 10%(P)

ƒ Avoid T&P • Insulation • Inhibitor Injection

Management ƒ Prevent Blockages • Kinetics • Time Dependent • No Agglomeration

ƒ Examples • • • •

Anti-Agglomerants Slurry Flow Plug Remediation Electrical Heating

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Conceptual Model of Hydrate Formation in Oil-Dominated System water entrainment

water drops form hydrate shells, ptle size unchanged (D.Turner)

plug

agglomeration

gas oil water hydrate shells

time capillary attraction

Agglomeration Prevention = Plug Prevention

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Model Development to Predict Hydrate Blockages FBRM/PVM – Particle Size Analysis & Agglomeration

MMF – Adhesion Forces Film Growth & Film Strength

CSMHyK/OLGA 2000 Simulator Hydrate Growth in Multiphase Pipeline Flow

Flow Loops (Texaco, ExxonMobil, TU)

HP-DSC Agglomeration

Rheometers

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Hydrate Agglomerate Morphology Determined with Simultaneous PSD FBRM

0 10 20 30 40 50 60

60

40 30 20

15:00

10

PVM

fD 13:00

80 60

(J.Boxall)

Chord

40 20 Leng th [um ]

0

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

12:00

eo

0

T im

D. Greaves

14:00

ay

C ho rd C ou nt

50

DSC Tests of the Effect of Hydrates on Emulsion Stability Primary hydrate particle Hydrate shell

sII Hydrate Melting

Water Droplet

Water core

Emulsion

Hydrate Formation

Emulsion after hydrate dissociation

J. Lachance

(Redrawn from Palermo et al. 2005)

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Molecular Tools to Study Hydrate Formation & Decomposition

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Time-Resolved NMR 13C MAS NMR of CH –C H Hydrate 4 2 6 51262 cages decompose faster than 512 cages C2 gas phase C2 large cage

C1 C1 small large cage cage

C1 gas phase

Time (s)

Dec et al., J. Phys. Chem. B, 2007 Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Molecular-level Studies of Hydrate Formation & Decomposition H

O

H

I

O

H

Neutron source

H

O Q

H2O (l) + CnH2n+2 (g) @ 50-350 bar, 4-25 oC

H

Neutron Diffraction pattern

H

EPSR analysis

Hydration structure during hydrate formation & decomposition Buchanan, Soper, Koh et al., J.Chem. Phys. (2005) Thompson, Soper, Koh et al., J. Chem. Phys. (2006) Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

lij

Hydration Shell Expands on sI & sII Hydrate Formation Hydrate

Liquid

~1-2 Å expansion

sI sII

Increased order

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Hydrate Decomposition Over 21 hours To Remove Bragg Peaks 4500 4000

Roberts 1940 Deaton&Frost 1946 Kobayashi 1949

Pressure (psi)

3500 3000

McLeod&Campbell 1961 Marshall&Kobayashi 1964 Jhaveri&Robinson 1965

2500 2000 1500

Methane Hydrate

Gallow ay 1970

Decomposition (21 hrs) Formation

Falabella 1975 Verma 1974 de Roo 1983

12 hrs

9 hrs

Thakoe&Holder 1987 1000

Methane + Water

500 0 -10

-5

0

5

10

15

20

25

Tem perature (oC)

Investigating the well-documented ‘memory effect phenomenon’

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

“Memory effect” causes more rapid nucleation What causes the “memory effect”? • Residual amorphous structure, residual crystallites, or dissolved gas Decreasing Metastability On Hydrate Reformation

Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

No Change in Water Structure & Hydration Shell Before Formation & After Melting Before formation (points), after melting (solid lines) 5.0

7

HW-HW

4.5

6 4.0

C-HW

3.5

5

OW-HW

3.0

g(r)

g(r)

4

3

2.5 2.0 1.5

2

C-OW

1.0

OW-OW 1

0.5 0.0

0 0

2

4

6

r [Å]

8

10

0

2

4

6

8

r [Å]

‘Residual’ crystallites rather than amorphous structure attributed to the ‘memory effect’ phenomenon. Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

10

Future Directions: New Paradigms in Gas Hydrate Technology Improve Understanding & Control of Kinetics in: ƒ Gas recovery from hydrate deposits • assess dissociation techniques ƒ Assessing submarine hydrate dissolution rates • impact of dissociation to the environment ƒ Energy storage materials • develop synthesis & stability technologies ƒ Maintaining flow in pipelines • determine when & where a plug occurs Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

Acknowledgements Funding: ƒ National Science Foundation ƒ American Chemical Society ƒ Department of Energy – Basic Energy Sciences ƒ National Undersea Research Program ƒ Minerals Management Services ƒ CSM Hydrate Consortium: BP, Chevron, CononcoPhillips, ExxonMobil, Halliburton, Petrobras, Schlumberger, Shell ƒ DeepStar Consortium Collaborators: MBARI (P. Brewer, E. Peltzer) LBNL (G. Moridas, T. Kneafsey) RAL-ISIS, U.K. (A.K. Soper); ANL-IPNS (A.Schultz) CVX (J.L. Creek); NTNU, Norway (J. Sjoblum); IFP, France (T. Palermo) CSM (Matthew Liberatore, John Dorgan) Center Center for for Research Research on on Hydrates Hydrates & & Other Other Solids, Solids, Colorado Colorado School School of of Mines Mines

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