Study on dissociation characteristics of CO₂ hydrate with THF for cooling application

The CO₂ hydrate with tetrahydrofuran (THF) is used to study the kinetics of CO₂ hydrate dissociation. The experiments are conducted at temperature (279–280) K and moderate pressures (0.3, 0.4 and 0.5 MPa), which are suitable for the cooling application. These experimental conditions can also make sure that there is no dissociation of the THF hydrate. No kinetic model and experimental correlation to calculate the activation energy and dissociation rate of the CO₂ hydrate with THF has been found. From this study, it is found that the dissociation rate strongly depends on the temperature. A kinetic model is developed to predict the activation energy for CO₂-THF (5.56 mol%) hydrate, which fits well the experimental data with the error bands of ±8.2%. An experimental correlation for CO₂-THF hydrate dissociation rate is developed with the error bands of ±26.0%, which can be used to calculate the dissociation rate for estimation of cooling load for district cooling application. It is found that the activation energy ΔE for CO₂ hydrate with THF is estimated as 193.6 kJ/mol and the enthalpy of the CO₂-THF hydrate is measured to be 263.5 kJ/kg-H₂O. Based on the results, the CO₂ hydrate district cooling system with CO₂–THF hydrate slurry is simulated for 5000 RT, and the COP is estimated as 14.3.