Techno-economic process optimization for a range of membrane performances: What provides real value for point-source carbon capture?

Membranes provide a unique opportunity for heavy industry decarbonization and a real solution requires optimal system design. We use a superstructure process model to minimize capital and operational expenses for post-combustion carbon capture systems. We consider membranes having CO${}_2$ permeances between 100 and 5000 GPU and selectivities for CO${}_2$ over N${}_2$ ranging from 10 to 300. For the four heavy industry-representative cases studied, we find membranes with selectivities approximately above 30 have essentially the same economics. When the permeance of CO${}_2$ is above 1000 GPU, and the selectivity is between 20 and 30, we find that membrane systems can achieve low capture costs ($20 to $55 per ton) and high energy efficiencies (150 to 500 kWh per ton). A quantitative relationship between membrane properties and optimized process economics enables effective product development for commercial applications.