Eight CO2 capture processes were evaluated in terms of economics, environmental impact, and equipment footprint, based on rigorous modeling.
This research introduces a framework for evaluating eight representative CO2 capture processes, consisting of four standalone processes—namely, physical absorption (PHYABS), chemical absorption (CHEABS), dual-reflux pressure swing adsorption (DRPSA), and pressure-temperature swing adsorption (PTSA)—alongside four hybrid processes that combine different adsorption and absorption methodologies.
An integrated metric — the Economics, Equipment footprint, and Environmental Score (EEES) was developed to evaluate these processes.
The findings reveal that the standalone CHEABS process demonstrates the lowest EEES value of 0.120, underscoring its technological readiness and superiority relative to the other processes evaluated. Conversely, the standalone PHYABS (EEES=0.168) and the hybrid PHYABS/PTSA process (EEES=0.242) present themselves as viable alternatives, effectively balancing environmental performance with economic and spatial considerations.
The standalone PTSA (EEES=0.465) and DRPSA (EEES=0.706) processes are deemed less favorable due to their elevated utility requirements and larger equipment footprints. Similarly, the hybrid processes, including DRPSA/CHEABS (EEES=0.891), CHEABS/PTSA (EEES=0.837), and DRPSA/PHYABS (EEES=0.784), are less advantageous across all three evaluation metrics.
Furthermore, this study suggests that carbon permit prices have a minimal impact on the economic aspects of the processes. The variation in capturing costs resulting from the scalability of these processes was investigated. Given the low carbon permit prices compared to the capturing costs, government subsidies may significantly contribute to the advancement of relevant technologies within the industrial sector.
In summary, this study offers a comprehensive framework for evaluating CO2 capture processes and provides actionable recommendations for the deployment of these technologies.
Prof. Bor-Yih Yu’s email address: boryihyu@ntu.edu.tw