3D printed electrically conductive amine based sorbent for CO2 capture

Abstract

CO2 capture technologies are key to the ongoing energy transition towards a low-carbon future. Solid adsorption is a promising technology for carbon capture with potential energy savings for regeneration of the material compared to liquid absorption. An interesting route for regeneration is electrical swing adsorption (ESA). An electrically conductive sorbent for direct air capture (DAC) was developed by 3D printing. As sorbent material an amine based ion-exchange resin was selected based on its high CO2 capacity for DAC with silver coated glass flakes as electrically conductive additive. Different amount of flakes were added to study the percolation threshold of the sorbent. The heating of the sorbents was done by Joule heating and monitored by an infrared camera. Furthermore, the influence of humidity and temperature on the electrical resistivity and volume of the sorbent structures were evaluated.Solid amine based sorbents with 15 to 35 vol% of silver coated glass flakes were successfully printed. At 20 vol% of flakes, a higher electrical conductivity could be obtained at room temperature and lower humidity. If the humidity increases up to 75 %, the volume of the structures expands with 7 % which causes an increase in electrical resistivity and loss of percolation. At 25 vol% of flakes, percolation is obtained and the resistivity is low enough (<10 Ohm.m) for Joule heating. This resistivity resulted in a heating time of 60 s for heating up to 70 °C, the regeneration temperature of the sorbent. These experiments demonstrate that printed solid amine based sorbent were successfully developed for CO2 capture and regeneration by ESA.