Volume 47

Synergistic promotion of CO2 hydrate kinetics enabled by coupling magnesium with amino acid Yan Li, Zhenyuan Yin, Yizhi Rao, Xuejian Liu, Yang Li

Abstract

In this study, we systematically investigated an environmental-benign kinetic promoter (L-leucine, L-Leu) coupling magnesium to enhance CO2 hydrate formation at the pressure of 3.5 MPa and temperature of 275.2 K. The induction time (tind) of CO2 hydrate was reduced to 696.65 minutes in the addition of 1.0 wt% L-leu. When magnesium was introduced to enhance CO2 hydrate formation, it showed a superior promotion effect on reducing tind to less than 10 s. In pure water, the dense CO2 hydrate film at the gas-liquid interface blocked the mass transfer and the CO2 gas uptake was 10.44 Vg/Vw. Therefore, magnesium was applied to trig CO2 hydrate nucleation coupling L-leu to realize rapid CO2 hydrate formation, followed by rapid P drop with the CO2 gas uptake of 78.77 Vg/Vw. In the coupling system, CO2 hydrate formation rate was promoted effectively with the t90 of 85.08 min under the static condition. This work contributes to offering considerable enhancement in the kinetic process of CO2 hydrate formation. which can be utilized for various hydrate-based technologies such as CO2 sequestration.

Keywords CO2 hydrate, ultra-rapid nucleation, kinetics, amino acid, magnesium, hydrate-based CO2 sequestration