Graphene oxide: An effective promoter for CO2 hydrate formation

Abstract

The main difficulties in applying technologies based on hydrate formation are the slow hydrate formation rate, low storage capacity, severe formation conditions and environmentally devastating promoters. Nano-sized graphene oxide has special microstructure features such as its functional groups and a large specific surface area, which can lead to high heat and mass transfer efficiency, large gas dissolution, fast nucleation and formation rate. In this work, CO2 hydrate formation with and without graphene oxide nanoparticles was investigated. Herein, the promoting mechanism and effects of graphene oxide concentrations in different initial pressures ranging from 3 to 5 MPa at 279 K on CO2 hydrate formation process were studied experimentally. The experimental results showed that graphene oxide can shorten the induction time by 53-74.3% and increase the gas consumption up to 5.1-15.9% under different system pressures. Based on the results, the optimum concentration was ascertained as 50 ppm under which condition, the induction time and the reaction time were the shortest while the pressure drop and the gas consumption reached the maximum.