Presentation given by Dr Stephanie Foltran from University of Edinburgh giving an update on UKCCSRC Call 1 Project "Determination of water solubility limits in CO2 mixtures to deliver water specification levels for CO2 transportation" in at the UKCCSRC Biannual Meeting - CCS in the Bigger Picture - held in Cambridge on 2-3 April 2014

1. - Call 1 project -
Determination of water solubility
limits in CO2 mixtures: Ensuring the
safety of CO2 transport
Stéphanie Foltran
Norhidayah Suleiman
Matthew Vosper
Ke Jie
Martyn Poliakoff
Mike George
UKCCSRC Biannual meeting - CCS in the Bigger Picture - Cambridge on 2-3 April 2014

2. Aim of our research
2
To establish the solubility limit of water in
impure CO2 to ensure the safety of pipelines
• For this presentation:
▫ Water solubility in CO2 + 5% N2 or in CO2 + 10% N2
at T = 40°C and P = 8 – 18 MPa
• Nobody has made such measurements before

3. Karl Fischer titration
Can detect µg of water Low temperature
FT-IR spectroscopy
Water highly absorbing in infrared
Long standing experience in the Group
with high-pressure vessel coupled to
infrared spectroscopy
Research Strategy:
2 independent methods
3

4. Background
• Literature data on water solubility in pure CO2;
• The presence of impurities changes the physico-
chemical properties of CO2!
4
0 5 10 15 20 25
0
200
400
600
800
Pure CO2
2 % H2
7.5% H2
10% H2
ρ(kg/m3
)
P (MPa)
50 o
C
SANCHEZ-VICENTE, Y., DRAGE, T.C., POLIAKOFF, M., KE, J., GEORGE, M.W., Int. J. Greenh Gas Con, Vol.13, 2013, p.78.
2% of H2 in CO2 can reduce the
molar density up to 25% in the
critical region

5. FT-IR spectroscopic set-up
5
N2
CO2
Gas mixer
IP: ISCO Pump
F: Fluid
S: Sample
HJ: Heating Jacket
EC: Equilibrium Cell

6. 6

7. 7

8. FTIR spectrum of CO2 + H2O
8
0
0.5
1
1.5
2
2.5
3
10002000300040005000
Absorbance
Wave number (cm-1)
ν1 + 2ν2 + ν3
ν2
2ν1 + ν3
CO2
H2O
CO2 CO2
ν3
CO2
4ν2 + ν3
(ν1 + ν3)
+(2ν2 + ν3)

9. 9
FT-IR spectrum of H2O in CO2 at 25°C, 9 MPa and with 0.2µl of H2O
FTIR spectrum of CO2 + H2O

10. 0.1µl
Procedure
10
0.2
0.3
0.4
0.5
0.6
1.31.4
1.5
Bending mode of H2O for different
concentrations at T and P fixed
ν2(H2O)
Saturation
quantity

11. 11
Z. Wang et al. Fluid Phase Equilibria 338 (2013) 155– 163
uncertainty
Saturation data
Calibration data
Our work: less than 4%
In the literature with a
similar method: 10% !
Uncertainty challenge

12. 12
H2O concentration
decreases by up to 59%
with the addition of N2
Concentration of water in CO2 mixtures
At = 40°C and P = 8 - 18 MPa in pure CO2
and in CO2 + (5-10%) N2 mixtures
3% of error compared with the literature

13. 13
10% N2 lowers the
solubility of the water in
CO2 by up to 26%
At = 40°C and P = 8 - 18 MPa in pure CO2
and in CO2 + (5-10%) N2 mixtures
Mole fraction of water in CO2 mixtures

14. EC: Equilibrium cell
SC: Secondary cell
Solubility of water in impure CO2 using
Karl Fischer titration
14

15. Equilibrium part
15
1. Pre-heater
2. Equilibrium cell
3. Secondary equilibrium cell
+ Filter
4. Sample loop

16. Conclusions
• Development of an FT-IR method to study the
solubility of water CO2 + impurities;
• The presence of N2 lowers significantly the
water solubility in CO2;
• Design of a high-pressure rig coupled to a Karl
Fischer.
16

17. Outlooks
• Solubility of water in
▫ CO2 + H2
▫ CO2 + O2
▫ and CO2 + H2 +N2
• Reproduction of the FT-IR results using the Karl
Fischer titrator
17

18. Acknowledgements
• Prof. Martyn Poliakoff and Prof. Mike George
• Dr. Ke Jie
• Matthew Vosper
• Norhidayah Suleiman
• Dr. Maria-José Tenorio
• Mark Guyler
• Workshop:
▫ Richard Wilson
▫ Peter Fields
• All the group
18
• UKCCSRC for funding
this project

19. Thank you for your attention!