(515b) Transformational Graphene Oxide-Based Membrane Process for Post-Combustion CO2 Capture

The Department of Energy (DOE), through its Carbon Capture Program, is investigating transformational, low-cost CO₂ separation and capture technologies that can be installed in new or retrofitted into existing pulverized coal (PC) power plants for CO₂ capture with a cost of electricity at least 30% lower than a supercritical PC with CO₂ capture, or approximately $30 per tonne of CO₂ captured.

We are developing a transformational graphene oxide (GO)-based membrane process that can be installed in new or retrofitted into existing pulverized coal (PC) or natural gas power plants for CO₂ capture with 95% CO₂ purity. The GO-based membrane technology builds on our pioneering work on the ultrathin, GO-based membranes published in Science (Li et al., Science, Vol. 342, no. 6154 (2013) 95-98) and Nature Communications (Zhou et al., Nature Communications, Vol. 8, doi:10.1038/s41467-017-02318-1342).

A facile and scalable coating process was developed to prepare ultrathin graphene oxide (GO)-based membranes on polyethersulfone hollow fibers for highly efficient CO₂/N₂ separation. The GO-based membranes developed to date exhibited extraordinary separation performance under simulated flue gas conditions with CO₂ permeance of 1,020 GPU and a CO₂/N₂ selectivity as high as 680. The selectivity is much higher than state-of-the-art membranes. In addition, after extensive material and structure optimization, we have also developed high-flux membranes with CO₂ permeance as high as 2,500 GPU using GO quantum dots (GOQD) as a membrane building block.

Our transformational GO-based membrane process (designated as GO²) integrates the high-selectivity and high-flux GO-based membranes and offers a new opportunity to explore further reductions in the cost of CO₂ capture. The GO² process, functionally, has the benefits of a hybrid system but the simplicity of a membrane system which also reduces the up-front installation costs and footprint and does not add circulating liquids to the power plant environment. Therefore, it facilitates the ease of integration into a power plant.