Dual Function Materials for Direct Air Capture of CO2

Direct air capture DAC of carbon dioxide is a promising technology that can potentially contribute to mitigation of CO2 emissions at scale and can be used as a sustainable carbon feedstock to produce synthetic fuels, chemicals, and construction materials. Current estimates for DAC suggest that it can cost between $300$1,500/tonne of CO2 captured. The proposed project is aimed at developing and optimizing materials and processes to significantly lower the cost of DAC. To achieve this goal, we are proposing to advance the development of a “reactive” DAC process which is capable of capturing as well converting CO2 from air into valuable products. In SBIR Phase I of this project, we have successfully demonstrated the technical and economic feasibility of this process intensified reactive capture DAC process using dual functional materials DFMs for capture of CO2 from air and its subsequent conversion into renewable natural gas RNG using renewable/waste hydrogen. The DFMs have shown high CO2 capacity under direct air capture of CO2 conditions in laboratory tests. The captured CO2 converts into CH4 during the regeneration step. We have designed a process based on the SBIR Phase I results and evaluated the economic potential of this process. In SBIR Phase I of this project, working with our research institute partner, Columbia University, we identified, synthesized and tested a ruthenium Rupromoted sodium oxide dispersed on alumina as DFM for this process. This DFM exhibited a high CO2 adsorption capacity and capture kinetics in ambient air. The extent of CO2 capture % removal of 400 ppm CO2 in air was significantly higher in presence of atmospheric moisture relative humidity in air, unlike physical sorbents like zeolites, aluminas, metal organic frameworks MOFs and even aminebased CO2 capture sorbents. This DFM also showed a very fast mass transfer rate during adsorption without any noticeable aging/degradation. Preliminary technoeconomic analysis shows that the DACDFM process is a promising technology with a high rate of return on the investment. The proposed Phase II project is aimed at 1 further optimizing the DFMs and process cycle and build a highfidelity benchscale prototype unit to perform parametric and longterm testing to obtain engineering data needed for a pilot system design for next step of technology development 2 optimizing DFM on the selected support structure to achieve maximum CO2 adsorption capacity, low pressure drop and conversion into methane, 3 developing a process model to accurately represent the DACDFM process, and 4 performing and refining the technical economic assessment TEA obtained in SBIR Phase I to evaluate the commercial potential of the DACDFM process. The anticipated benefits of the proposed DACDFM process are the lowering of the DAC and the production of RNG. DAC is location independent and can be built on nonarable land. The RNG produced has a large market as it is needed by large utilities to lower their emissions and by petrochemical companies as renewable hydrocarbon feedstock. The DACDFM process will mature into a competitive market solution and the production of RNG will significantly accelerate penetration of DAC technologies to reach the net zero target proposed by President Biden by 2050.