A Systematic Method for Membrane CO₂ Capture Modeling and Analysis

This work presents a new systematic methodology for the design and optimization of membrane systems for CO₂ capture integrating both technical and cost models. In this methodology, graphical solutions to the separation problem are generated to design a cost-optimal membrane system (process configuration, operating conditions) that satisfy CO₂ capture ratio and product purity requirements.

The methodology developed is illustrated through the design of a post-combustion CO₂ capture membrane system installed on an ASC power plant and its comparison with a MEA capture unit. This cost-optimal design of the membrane system leads to a levelized cost of electricity (LCOE) of 94 €/MWh which is 58% more expensive than the plant without capture and at the same price level as the reference plant with MEA CO₂ capture. The subsequent CO₂ avoided cost is evaluated to be 53 €/tCO2,avoided for both the membrane and MEA CO₂ capture system.

Finally a comparison between the cost model considered and models available in the literature is performed in order to demonstrate that the competitiveness of the membrane system designed in this paper is due to an improved design and not a possible underestimation of the membrane capture cost.