|Title||Electrical energy from CO2 emissions by direct gas feeding in capacitive cells|
|Author(s)||Legrand, L.; Schaetzle, O.; Tedesco, M.; Hamelers, H.V.M.|
|Source||Electrochimica Acta 319 (2019). - ISSN 0013-4686 - p. 264 - 276.|
|Publication type||Refereed Article in a scientific journal|
|Keyword(s)||Capacitive cell - Capacitive deionization - CO - Membrane potential - Mixing energy|
This work demonstrates the possibility to harvest electrical power from CO2 emissions by feeding CO2 and air gas directly into a capacitive cell. Hamelers et al. previously showed, that the available mixing energy of CO2 emitted into the air can be converted into electricity, but at high energy costs for gas-sparging in the process. In the present work, electrical power is generated by feeding the gas directly into the capacitive cell. We investigated three different cell designs (namely, “conventional”, “flow-by(wire)”, and “flow-by(flat)”), by changing both electrode and cell geometry. The flow-by(flat), inspired from fuel cell design, showed the best performance thanks to a high membrane potential (≈190 mV), which is the highest value so far reported from CO2 and air. A maximum membrane permselectivity between CO2 and air of 90% was obtained, i.e., almost double of values reported in previous studies. On the contrary, the “conventional” cell design gave poor performance due to non-optimal gas flow in the cell. We highlight the importance of water management and internal electrical resistance, to indicate directions for future developments of the technology.