Preparation of amine functionalized reduced graphene oxide/methyl diethanolamine nanofluid and its application for improving the CO2 and H2S absorption.

A novel approach was examined by addition of amine-modified reduced graphene oxide (rGO) to amine solutions in order to enhance the CO2 absorption capacity of amine solutions. Amine functionalized reduced graphene oxide (rGO)/methyl diethanolamine (MDEA) nanofluid was prepared for absorption of acid gases (CO2, H2S). GO was synthesized via a modified hummer method and functionalized through solvothermal method. As-synthesized NH2-rGO was characterized by XRD, BET, SEM, FTIR, EDX and XPS analysis to determine the structure. NH2-rGO was dispersed in MDEA and displayed excellent stability verified by zeta potential analysis. NH2-rGO/MDEA nanofluid showed high absorption capacity toward CO2 and H2S. The absorption capacity of the solution for CO2 and H2S was promoted up to 16.2% and 17.7%, respectively. Solubility results showed a reverse relationship with increasing temperature. Comparison of solubility data revealed that introducing 0.1 wt% NH2-rGO to 40 wt% had a greater enhancement relative to introducing 0.1 wt% GO to the same solution.