Membrane system design and process feasibility analysis for CO2 capture from flue gas with a fixed-site-carrier membrane

• The criteria on energy consumption and cost estimation are provided.
• A general method for membrane system design is provided.
• Process design and optimization Integration of compression heat.
• Techno-economic feasibility analysis on membrane system for CO2 capture.

Seeking an energy efficient and environmentally friendly technology for CO2 capture could be promising for reduction of CO2 emissions. Membranes have already been commercially used for selected gas separations and have potential to be used for CO2 capture. However, process and economic feasibility of membrane separation system significantly depends on not only membrane materials but also process operating conditions. Thus, membrane system design by process simulation was conducted in this work. A single stage membrane unit was designed to accomplish specific separation requirements of >80% CO2 capture ratio at a maximum acceptable membrane area 600,000 m2. The obtained characteristic diagrams showed that a minimum membrane performance of CO2 permeance 2 m3 (STP)/(m2 h bar) and CO2/N2 selectivity 135 should be achieved at a stage-cut of 15.2% and a feed and permeate pressure of 2.5 bar and 250 mbar, respectively. A two-stage membrane system using high performance fixed-site-carrier membranes by integration of compression heat was designed to achieve >80% CO2 capture ratio and >95% CO2 purity from a 18,260 kmol/h flue gas in a refinery. The simulation results showed nice potential for CO2 capture with a specific energy consumption of 1.02 GJ/ton CO2 and a capture cost of 47.87 $/ton CO2 captured.

Fig. 6 in manuscript: PFD of a two-stage membrane system for CO2 capture from RCC flue gas by integration of compression heat.Figure optionsDownload as PowerPoint slide