The proof of concept study on the selective transport of CO2 from PG was demonstrated by Bunch and coworkers in 2012. This was a fundamental study from a micron-sized exfoliated graphene with only a couple of pores responsible for gas transport. However, for practical membranes, one must prepare macroscopic films. For this, polycrystalline graphene, produced by chemical vapor deposition (CVD) on Cu foil, has become a standard material. Yet, it is challenging to prepare a large-area PG membrane. Several aspects of the PG membrane must be debottlenecked to become commercially attractive for carbon capture. This includes reducing membrane element cost, scalable incorporation of CO2-selective pores in graphene, and crack-free fabrication of membranes. These challenges are elaborated below.