A study on the influence of nanofluids on gas hydrate formation kinetics and their potential: Application to the CO2 capture process

• The effects of Al2O3, SiO2, Ag and Cu nanoparticles on kinetics of CO2CH4 hydrate formation process were studied.
• The CO2CH4 hydrate formation was studied in pure water and water containing a 0.1, 0.2 and 0.3 wt% of each nanoparticle.
• The effects varied from one nanoparticle to another and were more pronounced during crystallization than dissolution.
• Nanoparticles with high specific surface area had the most positive effect.

In this work, the effects of Al2O3, SiO2, Ag and Cu nanoparticles on the kinetics of CO2CH4 hydrate formation process were experimentally studied by measuring the amount of gas consumed and the rate of gas consumption. A suspension of 0.1 wt%, 0.2 wt % and 0.3 wt% of each nanoparticle was injected into the hydrate formation reactor, while pressure and temperature were maintained at 4.0 MPa and 274.15 K, and the magnetic stirrer speed was set at 350 rpm. The CO2CH4 hydrate formation process was studied in both pure water and water containing a 0.1 wt%, 0.2 wt% and 0.3 wt% of each nanoparticle suspension. The results showed that these nanoparticles had a positive effect on hydrate formation. These effects varied from one nanoparticle to another. It was observed that nanoparticles of SiO2 had the most positive effect on CO2 gas consumption, particularly at a concentration of 0.3 wt%. At this concentration the average amount of gas consumed was about 45% higher than that in pure water during the dissolution and 77% during crystallization. Cu and Al2O3 nanoparticles had an intermediate effect with improvement in gas consumption by 1%–15% during dissolution; while it had an important impact on gas consumption during hydrate crystallization with an improvement of 30%–65%. Ag nanoparticles had no significant effect during these two phases.