Rigorous Approach to the Prediction of the Heat of Dissociation of Gas Hydrates

Abstract

This paper presents a theoretically correct method for predicting the heat of dissociation of gas hydrates using a fugacity-based model. Based on the Clausius-Clapeyron equation, the proposed approach takes into account the difference in compressibility by phase transition and the solubility of a guest component in the liquid phase. It is found that, for specific gas hydrates, the effect of two correction factors on the prediction of the heat of dissociation is not negligible. All corresponding properties including the hydrate number, compressibility, solubility of gas in water, water content in the vapor phase, and heat of dissociation are calculated and compared with experimental values in part.

Prediction of CH4 and CO2 hydrate phase equilibrium and cage occupancy from ab initio intermolecular potentials

“…Table 9 compares the hydration number, predicted by this model, with experimental data. It can be seen that our predictions agree with the experimental data reported by Anderson (2003), Henning et al (2000), Udachin et al (2001) and Yoon et al (2003).…”

“…Uchida (1997) pointed out that the techniques for measuring the hydration number directly suffer from many problems concerning sample preparation and assumptions made in analysis. Based on the Clausius-Clapeyron equation, Larson (1955), Yoon et al (2003), and Anderson (2003) derived the hydration number from the dissociation enthalpy of CO 2 hydrate. Table 9 compares the hydration number, predicted by this model, with experimental data.…”

A cometary nucleus model taking into account all phase changes of water ice: amorphous, crystalline, and clathrate

“…The enthalpy of formation of single guest clathrates is then independent of the clathrate structure, the hydration number n hyd , the gas distribution between cavities, the temperature and the pressure (Avlonitis 2005). His model corroborates in every case the experimental data of Handa (1986a,b) and Anderson (2003) as well as the results of Yoon et al (2003), which were derived by application of the ClausiusClapeyron equation (See Eq. (50)).…”

Phase equilibrium condition measurements in carbon dioxide clathrate hydrate forming system from 199.1 K to 247.1 K

“…B, initial; >, CO 2 hydrate formation; ,, stepwise temperature increasing process; -, obtained phase equilibrium conditions. 272.12 K based on the Clausius-Clapeyron Equation [19], and no data on the enthalpy were reported below 259.15 K. Then, to estimate the dissociation enthalpy of CO 2 hydrate at lower temperature than the above temperature, we applied the Clausius-Clapeyron equation written in following form to the measured equilibrium data with the assumption that the dissociation enthalpy of CO 2 hydrate is constant at the temperatures,…”