Post-combustion CO2 capture via the hydrate formation at the gas-liquid-solid interface induced by the non-surfactant graphene oxide

Abstract

CO2 capture is currently the most effective way to reduce global carbon emissions, which leads to the emergence of novel gas hydrate method. In this work, the significant role of graphene oxide (GO) in enhancing the dynamic behaviors of post-combustion CO2 capture via the hydrate formation was investigated. Firstly, at the gas-liquid interface, the induction of GO increased the amount of gas transfer, and shortened the induction time for the hydrate nucleation at the heterogeneous nucleation sites provided by GO, which attracted CO2 molecules assembling on the GO layer to participate in the hydrate nucleation based on the molecular dynamics (MD) simulations. More importantly, the hydrate growth rate was nearly doubled in 0.05 wt% GO and 4 mol% tetrahydrofuran (THF) mixed accelerators than that in pure THF and sodium dodecyl sulfate (SDS) mixed systems, which greatly boosted the gas storage capacity of CO2 in the form of compact solid hydrates. Consequently, CO2 separation efficiency achieved up to 76 % in the GO based accelerators, enhanced by 23.2 % compared to that in pure THF and the SDS mixed systems. The present study could provide insights into the development of new type of nanomaterial accelerators for CO2 capture via the gas hydrate method.