Design and Implementation of a CO₂ Capture Device Utilizing Photothermal Effect

Current aqueous-amine carbon capture methods have been limited by the lack of available energy sources and the energy-intensive process of separating CO2 from capture solutions. This process requires substantial energy inputs to heat the solution and regenerate the solvent. Previous research has demonstrated that photothermal excitation of nanoparticles can initiate the release of CO2 using less energy than that required for heating the bulk solution. This phenomenon has the potential to significantly reduce the overall energy cost of carbon capture methods by increasing the CO2 release efficiency using localized photothermal heating and solar energy. Here, we propose using a photothermal effect in a device for passive extraction of CO2 from point sources and continuous regeneration of the solvent through solar energy. We demonstrate a bench-scale device for continuous, passive extraction that uses suspended carbon-black nanoparticles in a capture solution as a layer between a porous membrane and a transparent window. While the device can run continuously, we suggest that day to night cycling of the light source may optimize CO2 loading and release. Through localized photothermal heating and solar energy, this device has the potential to enhance the CO2 release efficiency and reduce energy costs for carbon capture.