1. Poly(ionic liquid)s for Selective Carbon Capture
Peter Styring
Professor of Chemical Engineering & Chemistry
Chemical & Biological Engineering
The University of Sheffield

2. CCS/CCU Process C-1 chemistry C-12 / C-18 T, p Storage CO2 Air
pipeline
CO2
Air
Catalytic Reactor N2
EWP
CO2
Municipal waste
C-1 chemistry
CO2
Capture H2
power
water
heat
C-12 / C-18

3. Capture
Current state of the Art is aqueous solutions of monoethanolamine (MEA) at concentrations of 15-30% (w/w)
MEA has problems of toxicity, corrosion, reactive chemistry and evaporative loss
Strong interaction between CO2 and basic NH2 group
Mixture of physi- and chemi- sorption
Energy requirement for desorption makes the process energy intensive
Over 70% of the absorber is occupied by water which has implication on capital expenditure
Need materials that show selective physisorption

4. Possible Adsorbents

5. Poly(ether) absobents
O. Aschenbrenner & P. Styring, Energy Environ. Sci. 2010, 3, 1106
Poly(ether) absobents

6. CO2 / N2 Solubility
Substance
Solubility of CO2 (mmol/l)
Solubility of N2 (mmol/l)
Glycerol
391
333
Glycerol carbonate
251
220
Tetraglyme
111 52
PEGDME 150
158 91
PEG 200
343
359
PEG 300
344
189
PEG 600
197
190
Poly(ethylenimine)
>71
233
Methanol
138 7
Water 34 1
Comparative molar solubilities of carbon dioxide and nitrogen at 25 °C for the pure gases in the test adsorbents under identical conditions

7. Desorption from PEG150

8. Ionic liquid & Poly(Ionic liquid) absobents
O. Aschenbrenner, S. Supatitmongkol, M. Taylor & P. Styring, Green Chem. 2009, 11, 1217
Ionic liquid & Poly(Ionic liquid) absobents

10. Isothermal thermogrammes for [C2mim][ES] at 120 and 220 °C after an initial in situ drying procedure

11. Vapour Pressure Calibration by TGA

12. Vapour Pressures of Ionic liquids by TGA
Detectable vapour pressures, higher than expected:
e.g. [C2mim][ES] Vp = 2.0 Pa at 120 ⁰C
Is it the IL vapour, impurities or decomposition products?
TGA-MS analysis showed some evidence of IL
Headspace MS at 100 & 200 ⁰C showed conclusive evidence.

13. Head Space MS [C2mim][ES]

14. CO2 Adsorption Capacity by TGA
S. Supasitmongkol & P. Styring, Energy Environ. Sci. 2010, 3,

15. Selectivity (TGA)

16. Bench Scale Absorber

17. Bench Scale Absorption

18. Bench Scale Selectivity

19. [C2mim][ES] by TGA

20. PIL by TGA

21. [C2mim][ES]

22. ILm & PIL

23. Release Lower energy than amines IL monomer shows slow release (blue)
PIL (red) releases CO2 rapidly
Reduces materials requirements
Negligible evaporative loss for PIL
Relatively low material and operating costs (Design Projects)

24. Acknowledgements Dr Ortrud Aschenbrenner Somsak Supasitmongkol
Dr Marie Taylor
Nicole Tan
Dr Jamil Khan
Dr Francis Clegg (SHU)
Simon Thorpe
Royal Thai Government and National Metal and Materials Technology Center (MTEC)
EPSRC “C-Cycle Consortium” (EP/E010318/1)

25. Carbon Capture and Utilisation in the green economy
Using CO2 to manufacture fuel, chemicals and materials
Authors
Peter Styring (The University of Sheffield), Daan Jansen (ECN)
Co-authors
Heleen de Coninck (ECN), Hans Reith (ECN), Katy Armstrong (The University of Sheffield)