Direct Air Capture of CO2 Using Rotating Air Contactor with Potassium Hydroxide and Guanidine-Based Ligands

The solution proposed in this invention disclosure combines a rotating air contactor (RAC) system with the utilization of environmentally friendly amino acid salts, specifically potassium hydroxide (potassium sarcosinate, K-SAR), and guanidine-based ligands (methyl-glyoxal-bis-iminoguanidine, MGBIG), to address the challenges of direct air capture (DAC) of carbon dioxide (CO2) from the atmosphere.

The RAC system is designed to overcome the problem of collecting carbonate crystals that typically occur during the cyclic operation of liquid solvent-based CO2 absorption DAC systems. By incorporating a rotating mechanism, the RAC enables efficient collection of carbonate crystals in the solution, preventing their aggregation or sticking. This novel design overcomes a common limitation of traditional DAC systems, ensuring improved efficiency and performance. Within the RAC system, the environmentally friendly amino acid salts, K-SAR and MGBIG, act as absorbents for capturing CO2 from the air. These absorbents undergo a chemical absorption process, forming a solution that contains both K-SAR and MGBIG. This solution facilitates the precipitation of captured CO2 as solid carbonate when exposed to atmospheric CO2. This phase change not only enables effective CO2 capture but also has the potential to reduce the energy requirements for the subsequent regeneration process.

By combining the innovative RAC system with the utilization of environmentally friendly amino acid salts, this invention aims to optimize the efficiency and effectiveness of DAC technology. The rotating mechanism of the RAC system ensures efficient collection of carbonate crystals, while the absorbents facilitate effective CO2 capture and precipitation.