Objectives of project
The project addresses one of the challenges of the 21st century – capturing CO2 (CCS) and converting CO2 into organic molecules (CCU). CO2 is the major greenhouse gas and reducing the concentration of it in the atmosphere is essential for survival and sustainable living of humans on Earth. Direct emission of CO2 from the Industrial processes and equipment account for more than 22% of all global CO2 emissions. The METAMORPH project will target this anthropogenic production of CO2. We propose a system for direct photocatalytic conversion of CO2 and H2O to fuels and/or chemicals at the industrial site, before it reaches the atmosphere. The produced carbohydrates (ethanol/methanol) can then be reused at the site or transported elsewhere for use in the fuel and other chemical industries.
The current efforts to reduce the CO2 concentration in the atmosphere are focused on carbon capture and storage (CCS). CCS is expected to handle about 13 Mt CO2/year, and given the annual emissions in the order of 30 Gt CO2/year is not a sufficient solution to achieve carbon neutrality. Moreover, safety of storage sites has to be ensured for thousands of years that requires technological and economical investment. As an alternative, CCU approach can be employed that utilizes captured CO2 conversion to chemicals/fuels. However european zero emission platform (ZEP) analysis suggests that CCU can only address a small proportion of the emissions with main technological barrier being an efficiency of the CCU materials (carbon footprint of the CCU materials themselves may be higher than CO2 reduced) and economic (the cost of the synthesized products is several times higher). The METAMORPH will combine the state-of-the-art materials to further improve the CCS capacity and achieve the commercially viable CCU solution.
In the first stage of the project a CCS material with superior sorption capacity will be developed. The sorption reactor will be based on carbonized polyaniline (PANi) material in different morphologies: nanofibers, bulk material, microparticles. Such materials were developed by UCT and demonstrated CO2 sorption ability on the order of 9.14 mmol/g, which is the highest capacity achieved for carbon based materials. Then, these CCS materials will be combined with photocatalysts, for CO2 conversion to carbohydrates that can be reused as an industrial raw material. The key limitation of currently available carbon capture and utilization (CCU) materials is their low efficacy in real industrial settings. That is mainly caused by low CO2 concentration reaching the active sites of the photoreactor. During the METAMORPH project, the CO2 absorbing materials (especially polyaniline nanoparticles) will be combined with the photocatalytic systems. That will overcome this problem by locally increasing the CO2 concentration and its availability for photocatalysis. Finally, the combination of these hybrid absorbing/catalytic nanoparticles will be combined with the nanofibrous membranes to further increase the surface area available for the adsorption and providing mechanical support. The use of nanofibrous membranes will also increase the processability of the CCU systems and the ability to incorporate them into the deployable photocatalysts. During the project a new reactor for pilot-scale CO2 capture and photocatalytic conversion into organic molecules and high-value products will be developed. The project will deliver an environmental impact by reducing CO2 emissions (CCS and CCU) and economic impact by production of useful organic molecules (CCU). The CCS and CCU options that will be enabled by METAMORPH are summarized in Figure 2.
Figure 2: Carbon Capture and Utilization Options that will be enabled by METAMORPH membranes.