Characteristics of CO₂ hydrate formation/dissociation in H₂O + THF aqueous solution and estimation of CO₂ emission reduction by district cooling application

CO₂ conversion by gas hydrate is considered one of most practical technologies in the fields of Carbon Capture, Utilization and Storage (CCUS). In this study, the effects of hydrate formation pressure and concentration of tetrahydrofuran (THF) on the CO₂ + THF hydrate formation and dissociation performance are investigated, and the reduction of CO₂ emission by applying the CO₂ + THF hydrate for district cooling system is also evaluated. The CO₂ capture ratio tends to increase with increasing the hydrate formation pressure and THF concentration. It is found that the CO₂ regeneration rate increases with decreasing the formation pressure and the increasing rate decreases with time. It is concluded that the optimum conditions for the CO₂ + THF hydrate formation and dissociation are 1.5 MPa, THF 1.5 mol% to use hydrate slurry as the working fluid for district cooling application. Also, the dissociation enthalpy of CO₂ + THF hydrate was measured by using the high pressure micro-differential scanning calorimeter. The cycle simulation of hydrate cooling system is conducted, and the COP is estimated as 11.55. Finally, it is estimated that 20,684 tons of CO₂ emission could be reduced per year if the CO₂ + THF hydrate technology is applied to the district cooling system of 51,600 RT.