ETP Annual Conference 2017
Edinburgh, 10th October 2017
Demonstration of CO2 capture rate control at pilot scale using continuous online solvent measurements
Paul Tait1, Dr Bill Buschle2, Dr Kris Milkowski3, Dr Muhammad Akram4, Prof Mohamed Pourkashanian5, Dr Mathieu Lucquiaud6
1The University of Edinburgh, School of Science and Engineering, The King’s Buildings, Mayfield Road, Edinburgh, UK,
2The University of Edinburgh, School of Science and Engineering, The King’s Buildings, Mayfield Road, Edinburgh, UK,
3Sheffield University,Low Carbon Combustion Centre, Crown Works Industrial Estate, Rotherham Road, Sheffield, UK,
4Sheffield University, Low Carbon Combustion Centre, Crown Works Industrial Estate, Rotherham Road, Sheffield, UK,
5Sheffield University, Energy Engineering Group, Arts Tower lvl 1, Western Bank, Sheffield, UK,
6The University of Edinburgh, School of Science and Engineering, The King’s Buildings, Mayfield Road, Edinburgh, UK,
Summary
Post-combustion CO2 capture has the potential to provide additional operating flexibility to fossil thermal power stations. In this study, we demonstrate flexible operation at pilot scale and use online measurements of solvent composition are used to control the level of CO2 capture from coal-equivalent flue gas.
Abstract
Flexible carbon capture and storage (CCS) has the potential to play a significant part in the decarbonisation of electricity generation systemswhich conatin large amounts of intermittent renewable capacity. Post-combustion capture (PCC) with amine solvents is currently the state-of-the-art for CO2 emissions reduction from thermal fossil power stations. Variation of the level of steam extraction from the generation plant can allow the capture facility to provide additional operating flexibility and value for power stations which are slow to change output.
Advanced control architectures have the potential to maintain plant operation within pre-defined environmental, economic, and operational boundaries (Luu et al., 2015). Such control architectures will require lean and rich solvent composition to be used as critical process control variables. The development of methods for rapid, continuous online solvent analysis is ongoing (van Eckeveld et al., 2014), but the majority of these techniques are unproven outside of lab-scale testing.
During a pilot-scale test campaign at the UKCCSRC’s PACT amine pilot facility, online solvent measurement sensors are used to continuously measuresolvent amine concentration and CO2 loading. These measurements, combined with knowledge of plant hydrodynamics and response times, are used to demonstrate control of CO2 capture rate for a simple reboiler steam decoupling event. The flow of regenerative steam to the reboiler is shut down and as a result, the CO2 capture rate begins to decrease. The objective is to use continuous lean solvent loading measurements to determine when the reboiler must be switched on again to achieve a “target” minimum CO2 capture rate of 30%.
A minimum capture rate of 26.38% is achieved. While scope for improvement exists and the method must continue to be developed, this represents a significant practical step towards the control of the CO2 capture plant using online solvent measurement.
References
[1]Luu, M.T., Manaf, N.A. and Abbas, A. (2015). International Journal of Greenhouse Gas Control, 39, 377-389.
[2]van Eckeveld, A.C., van der Ham, L.V., Geers, L.F.G., van der Broeke, L.J.P., Boersma, B.J. and Goetheer, E.L.V (2014). Industrial and Engineering Chemistry Research, 5515-5525.