Experiments on the continuous separation of gas mixtures via dissolution and hydrate formation in the presence of THF

• We achieved continuous separation by dissolution, hydrate formation, and dissociation.
• The continuous separations of various gas mixtures were conducted in THF solution.
• We measured the concentration and refractive index of THF solution.
• The dissolved quantities of gas mixtures in THF solution were calculated by UniSim.

Hydrate separation technology has been widely applied to the separation of various gas mixtures with its own unique advantages over the past several decades. However, so far the relevant studies seem to be elementary and exploratory, and most of the separation processes are batch-type and not appropriate of practical uses. To promote the development of hydrate separation technology and to realize its industrial application early, we systematically investigated the continuous separation of CH4–N2, CH4–H2 and CO2–N2 gases respectively by hydrate method using 6 mol% tetrahydrofuran (THF) solution as the liquid medium in this work. The results demonstrate that the continuous process of sequential hydrate formation and dissociation can be achieved in the presence of THF under appropriate temperatures and pressures, and the gas mixtures can be separated to some extent after liquid absorption and hydration reaction. The continuous separation process in this work provides an achievable approach for the application of hydrate separation method.