CO2 absorption enhancement in graphene-oxide/MDEA nanofluid

Abstract

Graphene-Oxide (GO)/MDEA nanofluid was prepared for CO2 absorption enhancement in gas sweetening process. GO was synthesized using a modified Hammer method and characterized by XRD, BET, SEM and IR spectroscopy to determine the structure. The XRD analysis showed a strong peak at 2θ = 10.3°. GO was dispersed in MDEA by ultrasonic treatment and zeta potential analysis was employed to examine the stability of the nanofluid. The measured zeta potential (35 mv) confirmed the excellent stability in the solution. GO/MDEA nanofluid showed high absorption capacities toward CO2 due to the high surface area and existence of OH groups on the GO surface and enhancement in mass transfer coefficient. When 0.1 wt.% GO was introduced to the 40 wt.% MDEA, the absorption capacity of the solution was promoted up to 9.1%. This enhancement for 0.2 wt. % slightly more while the solutions with higher GO content showed no significant enhancement in absorption capacity. This enhancement has a reverse and direct relationship with increasing temperature and pressure, respectively.