Generation laws and distribution characteristics of carbon dioxide hydrate in a reaction kettle

We analyzed the generation characteristics of hydrate in a reaction kettle and established a convection–diffusion model of temperature and carbon dioxide. The concentration of liquid carbon dioxide and carbon dioxide dissolved in water were geometrically modeled according to the density of carbon dioxide and its solubility in water under varying temperature and pressure. The distributions of temperature, carbon dioxide and hydrate were analyzed in the reactor during hydrate formation. The factors affecting carbon dioxide hydrate formation were studied. Simulations of hydrate formation were verified by laboratory tests. The results showed that the convective diffusion of gas greatly increased the rate of hydrate formation. Temperature has a greater impact than matter transfer on hydrate formation. At the initial reaction time, the hydrate mainly existed at the boundary, the two-phase interface and the position of the liquid carbon dioxide. Hydrate finally formed in the middle and was thinnest at the interface. The solid–liquid surface tension caused the liquid water to move upward and form hydrates in the carbon dioxide phase. Hydrate formation at the interface between the initial carbon dioxide and water prevented carbon dioxide from diffusing further into the aqueous phase, which hindered further hydrate formation.