Evaluating the economic potential of membrane technologies for post-combustion in existing combustion systems: Comparison with MEA-based system

• Advances in membrane-based CO 2 capture were evaluated based on CO 2 capture cost. • Membrane cost, membrane thinning, and replacement intervals were examined. • Membrane thickness should be ≤ 0.1 µm to make membrane separation advantageous. • Membrane replacement intervals need to exceed 5 years. • Low-cost electricity is a decisive factor for economic feasibility of CO 2 capture. Membrane-based post-combustion carbon capture technologies are emerging as promising alternatives to sorbent-based systems. While monoethanolamine (MEA) based systems serve as the benchmark for absorbent-based technologies, no standardized benchmark exists for membrane-based systems. This study evaluates the economic potential of membrane-based post-combustion carbon capture through process simulation and sensitivity analysis, using MEA-based absorption as a reference. Key advancements in membrane technology, including reduced membrane costs, membrane thinning, and extended replacement intervals, are examined. The analysis considers the tradeoff between permeability and selectivity, constrained by Robeson’s upper bound. The findings reveal that membrane thickness must not exceed 0.1 µm to achieve cost competitiveness with MEA-based CO 2 capture systems, assuming Japan’s grid electricity as the energy source. For instance, when CO 2 /N 2 selectivity is 30 or greater and membrane thickness is 10 µm, capital and membrane replacement costs account for at least 80 % of the total CO 2 capture cost. In contrast, when membrane thickness is reduced to 0.1 µm, these costs contribute a maximum of 45 %, while the variable operating cost, primarily electrical energy consumption, becomes the dominant expense in CO 2 capture. Additionally, membrane replacement intervals must exceed 5 years to maintain an economic advantage over amine-based chemical absorption. When membranes achieve a 5-year lifespan with a thickness of 0.1 µm or less and low-cost electricity is available, CO 2 capture costs can drop below 50 USD/t-CO 2 in furnace and boiler combustion systems.