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

Abstract

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 AE 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 kl/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. (C) 2016 Elsevier Ltd. All rights reserved.