Structural optimization of hybrid membrane-based CO2 capture process with condensation column

Membrane-based CO2 separation has been recognized as an eco-friendly technology for post-combustion CO2 capture, which can potentially replace conventional amine solution-based counterparts. However, the membrane process alone is not enough to achieve sufficient CO2 purity, thus necessitating a hybrid system that includes a subsequent CO2 condensation column to ensure a high purity level (≥99.9 %). Under this configuration, an important indicator of the trade-off relation between the membrane process and the condensation process is the CO2 purity obtained from the membrane process. While the development of membrane materials is accelerating toward highly permeable and selective membranes, it is important to identify the economically optimal CO2 purity as well as the key process design parameters in the hybrid process. In this study, we aim to find the optimal decisions considering a wide range of economic parameters and selectivity/permeability within the design space of advanced polymeric membranes. The apparent selectivity model is employed to describe the performance of the membrane separation process under the Robeson upper bound of polymeric membranes. A detailed technoeconomic analysis is conducted to assess the economic viability of the system. The results indicate that the optimal balance between selectivity and permeance, as well as the optimal intermediate CO2 purity, varies depending on the feed sources. A lifecycle assessment shows that a hybrid membrane-based CO2 capture process can achieve significantly lower CO2 emissions compared to conventional solvent-based capture methods, when integrated with renewable generations. [Display omitted] •Optimal design for hybrid membrane-based CO2 capture process is studied.•Dual-stage membrane process integrated with condensation column is considered.•Both economic and environmental performances are evaluated.•The impacts of key parameters on capture cost/material selection are analyzed.