Experimental study of carbon dioxide absorption by Fe2O3@glutamine/NMP nanofluid

Abstract

In this study, for the first time, the nanoparticle (NP) of Fe2O3@glutamine (C5H10N2O3) was synthesized to improve the Fe2O3 properties in absorbing carbon dioxide (CO2) using the base fluid of hydrous N-methyl-2-pyrrolidone (NMP) solution (50 wt%), as a physically powerful CO2 absorbent. To do this, several nano-NMP solutions, in different weight percentages of NPs, were first prepared. Then, in a batch setup, the nano-NMP solutions were directly exposed to CO2 gaseous (at the pressures of 20, 30, and 40 bar) to clarify the effects of the mass percentage of NPs and initial pressure on CO2 absorption. Results clearly illustrated that Fe2O3 nanofluid was not stable more than 0.025 wt%. However, Fe2O3@glutamine nanofluid was stable approximately two times more than Fe2O3 nanofluid due to the presence of glutamine as a hydrophilic agent in the structure of Fe2O3@glutamine. Moreover, in comparison to the base fluid (NMP solution), although Fe2O3 increased CO2 absorption up to 9.14%, Fe2O3@glutamine NPs caused the CO2 absorption to increase up to 19.41%, which can be determined as the chemical reactions of two amino groups in the glutamine structure with CO2 and also higher stability of Fe2O3@glutamine NPs compared to bare Fe2O3 NPs. To achieve accurate results, all the mentioned experiments were repeated 5 times. The performance of Fe2O3 and Fe2O3@glutamine NPs after the fifth trial reduced by less than 3.5%, which reveals that the synthesized NPs had almost stable efficiency throughout their applications.