Designing and testing optimal materials for direct air CO2 capture and conversion

Carbon management—including carbon dioxide capture, removal conversion—is poised to be the next major global industry, on the order of global waste management, to address impending climate change. At Lawrence Livermore National Laboratory (LLNL), we study the role of carbon removal and conversion in this emerging industry and develop the technologies that will be required to support this emerging industry. I will discuss two of our recent efforts in direct air capture (DAC) and conversion of CO2. In the first, I will share our work aimed at understanding the key chemical and physical mechanisms underpinning oxidative degradation of aminopolymer-based DAC adsorbents, which can be a major cost driver for this technology. We find that while the polymer chemistry dictates the inherent susceptibility of the aminopolymer towards oxidation, the molecular mobility impacts the rate of key radical propagation reactions, potentially causing a switch the degradation-rate-controlling reaction mechanism. In the second, I will share our work on developing a material and process for capturing CO2 from the air and converting it to methane without first desorbing or concentrating the CO2, termed reactive capture and conversion. We demonstrate repeatable, high conversion of CO2 and reactive regeneration of the materials, allowing their reuse in a cyclic capture-convert process that produces synthetic methane potentially at a lower cost than alternatives.