Enzymatic CO2 Capture in intensified packed-bed column bioreactors: A techno-economic assessment

Abstract

To reduce the impact of industrial carbon dioxide (CO2) emissions on climate change, energy-efficient and cost-effective carbon capture technologies are needed. With this in mind, our research group has proposed an intensified enzyme-mediated CO2 capture process in packed-bed column bioreactors with carbonic anhydrase (CA) immobilized on the packing surface and on magnetic nanoparticles (MNPs). This study, in continuation of our efforts to amend these processes, aims to showcase a techno-economic assessment (TEA) of this promising technology in an industrial-scale context and to emphasize the inherent benefits of intensification. The TEA results suggest that this enzyme-mediated technology has the potential to reduce capture costs, chiefly due to the possibility of utilizing an alternative solvent that requires less energy to regenerate, while also being non-corrosive and non-toxic. The capture process consumes 39.8% less energy than the benchmark process utilizing a MEA-based solution. Immobilizing the enzyme on MNPs has tangible benefits, such as enhancing mass transfer and reducing the equipment footprint, which improves flexibility and contributes to the viability of the industrial process. The intensified enzyme-mediated CO2 capture process achieves a 28.6% reduction in capture cost compared to the benchmark technology. Sensitivity analyses were conducted to highlight the impact of key parameters on the overall cost-effectiveness of the technology, providing beneficial insights for further improvement. The results indicate that it is crucial to maximize enzyme lifespan and minimize energy consumption. The liquid flow rate and buffer concentration are additional constraints that should be thoughtfully considered to ensure the feasibility of this process.