盐水体系中环戊烷-甲烷水合物的相平衡及分解热

Phase equilibrium and dissociation heat of cyclopentane-methane hydrate in NaCl aqueous solution

利用可视化水合物相平衡实验装置,采用恒温压力搜索法,测定了284～303K内环戊烷(CP)-甲烷在NaCl溶液中的水合物相平衡数据,并采用Clausius-Clapeyron方程计算了其生成/分解热数据。实验结果表明,CP-甲烷水合物生成条件远低于纯甲烷水合物;采用甲烷辅助气体可使CP在高于其纯水合物四相点的更高温度范围内生成CP-甲烷水合物;CP-甲烷水合物相平衡压力随温度增大而升高;随着NaCl浓度的增大,相平衡压力线性升高,且温度越高,温度和NaCl浓度对相平衡压力的影响越大。CP-甲烷水合物的生成/分解热随着温度的升高而逐渐减小,随NaCl浓度的增加而减小。

The phase equilibrium data of cyclopentane （CP）-methane hydrates in NaCl aqueous solutions were measured by pressure search procedure with a viewable experimental apparatus for gas hydrate. The formation and dissociation heats of CP-methane hydrates were calculated based on these phase equilibrium data using Clausius-Clapeyron equation. The formation of hydrate became markedly easier after CP addition to methane. At temperature higher than the quadruple point of pure CP hydrate,CP-methane hydrates could be formed at a low pressure when methane was used as a help gas. The phase equilibrium pressure of CP-methane hydrates increased with the increase in temperature,and linearly increased with NaCl concentration in solution. Moreover,the effect of temperature and NaCl concentration was more obvious at a higher temperature. The formation and dissociation heat of CP-methane hydrates decreased with the increase in temperature and NaCl concentration.