Experiment Investigation of SiO₂ Containing Amino Groups as a Kinetic Promoter for CO₂ Hydrates

To diminish the greenhouse effect by reducing CO₂ emission into the air based on a capture and sequestration method through hydrates, the thermodynamic and kinetic effects of additives on CO₂ hydrate formation under 1.5 MPa in the presence of 5, 6, 8, 10, and 20 wt % RNS-A (reactive SiO₂ containing amino groups) were studied, and the stirrer speed was set to 800 rpm. This paper calculated the gas consumption and explained the possible mechanisms of RNS-A on CO₂ hydrates. The results showed that RNS-A was a kinetic additive instead of a thermodynamic one. It was found that 5-10 wt % RNS-A all shortened the induction time of hydrates, but only 5 and 6 wt % RNS-A increased the gas consumption of CO₂ hydrates. Although we observed the shortest induction time at a 10 wt % RNS-A system, the lowest gas consumption indicated its weak CO₂ capture and storage ability. In addition, when the concentration was 6 wt %, RNS-A had the highest gas consumption and its reaction time was relatively short. Considering the induction time and gas consumption, 6 wt % RNS-A was the optimal RNS-A concentration for CO₂ capture and sequestration, which was the most suitable for practical applications.