(415g) Scale-up of CO2-Selective Nanoporous Single-Layer Graphene Membranes

Atom-thick gas-sieving porous graphene membranes have shown great potential in post-combustion carbon capture. High CO₂ permeance of 10000 GPU and CO₂/N₂ separation factor of 30-80 from porous graphene membranes was recently achieved by our group^1–3, and a highly competitive capture penalty (below 30 $/ton_CO2) for post-combustion capture is assessed by a technoeconomic analysis^3,4. However, the current graphene membrane is still minuscule, and scalable fabrication routes are needed. The most predominant factor that restricts the upscaling of the graphene membrane is the crack formation during the transfer of graphene film from metal foil to a porous support. In this presentation, we will discuss several interventions that we carried out to realize large-area graphene membranes. We adopted the crystallization protocol of graphene to a low-cost Cu foil. We used acid pre-treatment on Cu foil to remove contamination particles that are detrimental to the graphene membrane. The acid treatment in the acidic solution was found to be effective even for low-cost Cu foils. High-quality 0.3 m x 0.1 m graphene coupons could be synthesized with a low density of intrinsic defects (figure a). The graphene film was mechanically reinforced with a CO₂-permeable layer and was transferred on a low-cost stainless-steel mesh while avoiding cracks and tears. The membrane was assembled inside a customized module and could be sealed without any leaks (figure b). The graphene films without any intentional pore generation step showed a low gas permeance confirming a low intrinsic defect density from graphene and crack-free membrane preparation. Incorporating graphene with CO₂-selective pores resulted in attractive CO₂-sieving performance from 50 cm² graphene coupons. Our work paves the way to up-scaling graphene membranes and achieving a competitive carbon capture cost (figure c and d).

Figure a) Large graphene coupons on Cu foil. b) Schematic of the membrane module. c) The evolution of the membrane area from 1 cm² to 5 cm² and to 50 cm². d) A large-area graphene coupon produced by the novel process described above. The ruler shows a graphene coupon successfully transferred on a high-flux porous support (PES). The coupon size is larger than 11 cm in size with an area higher than 50 cm², which is about 50 times larger than the state-of-the-art.

Reference:

(1) He, G.; Huang, S.; Villalobos, L. F.; Zhao, J.; Mensi, M.; Oveisi, E.; Rezaei, M.; Agrawal, K. V. High-Permeance Polymer-Functionalized Single-Layer Graphene Membranes That Surpass the Postcombustion Carbon Capture Target. Energy Environ. Sci. 2019, 12 (11), 3305–3312. https://doi.org/10.1039/C9EE01238A.

(2) Huang, S.; Li, S.; Villalobos, L. F.; Dakhchoune, M.; Micari, M.; Babu, D. J.; Vahdat, M. T.; Mensi, M.; Oveisi, E.; Agrawal, K. V. Millisecond Lattice Gasification for High-Density CO ₂ - and O ₂ -Sieving Nanopores in Single-Layer Graphene. Sci. Adv. 2021, 7 (9), eabf0116. https://doi.org/10.1126/sciadv.abf0116.

(3) Hsu, K.-J.; Li, S.; Micari, M.; Chi, H.-Y.; Zhong, L.; Villalobos, L. F.; Huang, S.; Duan, X.; Züttel, A.; Agrawal, K. V. Pyridinic Nitrogen Substituted Two-Dimensional Pores for Rapid and Selective CO2 Transport. Submitted.

(4) Micari, M.; Dakhchoune, M.; Agrawal, K. V. Techno-Economic Assessment of Postcombustion Carbon Capture Using High-Performance Nanoporous Single-Layer Graphene Membranes. Journal of Membrane Science 2021, 624, 119103. https://doi.org/10.1016/j.memsci.2021.119103.