This study reports a visual observation of the formation and growth of ionic semiclathrate hydrate on the surface of a Tetrabutylammonium bromide (TBAB) aqueous solution and CO2+N2 gas mixture. The composition of CO2+N2 gas mixture was 20 : 80. The experimental temperature range was from 280 K to 290 K, under the pressures of 2.3MPa and 4.7MPa, at wTBAB=0.10 and wTBAB=0.40, where wTBAB denotes the mass fraction of TBAB in the aqueous solution. At wTBAB=0.40, the hydrate crystals were initially observed to grow within the droplet, and followed by lateral growth at the droplet surface; but at wTBAB=0.10, the hydrate crystals grew exclusively in the liquid phase and did not cover the droplet surface. Two types of different crystals with different sizes were clearly observed.
IPCC. Climate Change 2014, Mitigation of climate change, Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change., Cambridge University Press, Cambridge (2014).
Kang SP, Lee H, Environ. Sci. Technol., 34, 4397, 2000