Phase Equilibria and Dissociation Enthalpies of Hydrogen Semi-Clathrate Hydrate with Tetrabutyl Ammonium Nitrate
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- 作者：Jianwei Du ; Liguang Wang ; Deqing Liang ; Dongliang Li
- 刊名：Journal of Chemical & Engineering Data
- 出版年：2012
- 出版时间：February 9, 2012
- 年：2012
- 卷：57
- 期：2
- 页码：603-609
- 全文大小：279K
- 年卷期：v.57,no.2(February 9, 2012)
- ISSN：1520-5134
文摘
This paper reports the experimentally determined thermodynamic stability conditions for the hydrogen semiclathrate hydrate generated from tetrabutyl ammonium nitrate (TBANO3) aqueous solutions at two mole fractions, 0.037 and 0.030, corresponding to the stoichiometric composition for TBANO3路26H2O and TBANO3路32H2O, respectively. The experiments for this three-component TBANO3 + water + hydrogen system were performed in the temperature range of (281.9 to 284.9) K and pressure range of (9.09 to 31.98) MPa with using a 鈥渇ull view鈥?sapphire cell. An isochoric equilibrium step-heating pressure search method was employed to determine the phase boundary between hydrate鈥搇iquid鈥搗apor (H-L-V) phases and liquid鈥搗apor (L-V) phases. The results showed that the semiclathrate hydrate of TBANO3路26H2O + H2 is more stable than that of TBANO3路32H2O + H2, with both of these semiclathrate hydrates being much more stable than pure hydrogen hydrate. The obtained phase equilibria data were analyzed using the Clausius鈥揅lapeyron equation to determine the dissociation enthalpy at the pressure range from (9 to 32) MPa. It was found that the mean dissociation enthalpies for the hydrogen鈥揟BANO3路26H2O and hydrogen鈥揟BANO3路32H2O clathrate hydrate systems were 322.53 kJ路mol鈥? and 340.23 kJ路mol鈥?, respectively.