随着油气资源的开采趋于深海,对促进水合物分解的研究在管道解堵和水合物开采方面都具有重要的意义.实验测试得到蔗糖的质量分数分别为0.05％、0.5％、2.4％、9.1％、20.0％、33.3％和39.4％.实验结果表明体系中蔗糖的存在对THF水合物的分解有促进作用,能降低THF水合物的分解平衡温度且分解平衡温度随着蔗糖含量的增加而降低;当蔗糖的质量分数大于27.7％时,THF水合物的分解平衡温度降至冰点以下.热力学模型以液-水合物-气三相逸度平衡为起始点,根据THF水合物的特点对传统的逸度计算模型进行了适当的简化,用基团贡献法计算得到了实验体系下水的活度系数,并利用实验数据拟合得到了模型中用于计算Langmuir常数的两个重要参数,最后选定适用于其他参数的经验公式.用该模型预测得到的水合物分解平衡温度与实验得到的数据相吻合,说明该模型可用于预测常压下的THF+水+蔗糖体系水合物分解平衡温度.本文建立的模型对不同客体水合物的热力学模型的建立也具有指导意义.%As the oil and gas resources exploitation in the deeper sea,the research of promoting the hydrate dissociation has the vital significance in the aspects of solving pipe blockage and hydrate exploitation.Sucrose at 7 concentrations of 0.05,0.5,2.4,9.1,20.0,33.3 and 39.4wt.％ was tested.The results showed that sucrose promoted the THF hydrate dissociation,reduced the balance of tetrahydrofuran hydrate dissociation temperature and the reduction of the temperature was along with the increase of sucrose concentration;the equilibrium temperature would below the ice point when the concentration was above 27.7 wt.％.The thermodynamic modelling used the fugacity of three phase equilibria of water liquid-hydrate-gas/vapor as the starting point,and simplified the traditional model of calculating the fugacity which was according to the characteristic of the THF hydrate,and calculated the activity of water in the experimental system by using the UNIFAC group-contribution model,and fitted the two important parameters which were aimed to calculate the Langmuir constant based on the experimental dates,and last,chose the appropriate empirical formulas for calculating the other parameters.A good agreement between the experimental measurements and the model predicting was observed which confirms the accuracy of the model used.The thermodynamic model built in this study also has guiding significance for building other thermodynamic model of hydrate of different guests.
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