6.9 Decarbonisation of seawater for CO2 capture and high-yield desalination
Desalination of seawater produces clean water, but requires energy and often emits CO2. At the same time, our oceans contain huge amounts of carbon dioxide, in equilibrium with the CO2 in the athmosphere. We have discovered a new technology to use as additional step in desalination, where CO2 is captured from seawater instead of from the atmosphere directly. An important additional advantage is that carbon dioxide removal prevents carbonate precipitates (e.g., limescale) during the desalination process. Hence, this combined desalination and decarbonisation provides the possibility to obtain a synergistic effect: the CO2 footprint of the desalination can be reduced by 2/3 and carbonate precipitation (i.e., CaCO3 scaling) can be avoided in the desalination process without adding chemicals. The captured CO2 can be stored to reduce the environmental CO2 concentration or used again as resource, and the carbonate removal increases the water yield and process economics.
The successful candidate will explore and further develop the CO2 capture from seawater. The concept of decarbonisation relies on changing the pH of the water stream, which can be facilitated in-situ by bipolar membrane electrodialysis (BPM-ED). Two possible operations are available. First, upon acidification of the salt water stream, bicarbonate will convert to carbonic acid, and can be extracted at low pressure. As a second operational mode, when the salt water stream is first basified, CaCO3 will precipitate, which can be harvested as a solid. This PhD research will study both experimentally and theoretically the mechanism, design and operation parameters for the crystallization process in BPM-ED configurations.
We are looking for a candidate with a MSc degree in chemical engineering, process technology, applied physics or a related field. You should have proven excellent experimental skills and should be able to take initiative in improving technologies. Knowledge of membranes, electrochemistry and/or microfluidics is considered as an advantage.
The PhD project will be executed within the Wetsus research theme Concentrates. The following companies are part of this theme: AquaCare, Shell, DOW Chemicals, Evides, and PWN.
Promotor: Prof.dr.ir. Chris Kleijn, thesis supervisor: Dr.ir. David Vermaas, both Department of Chemical Engineering, Delft University of Technology.
For more information contact: dr.ir Martijn Wagterveld (firstname.lastname@example.org).
Wetsus, Leeuwarden, The Netherlands