Abstract: The formation of hydrates is affected by many factors in which operational parameters are the most prominent variables. Hydration kinetics were analyzed under various initial pressures and operational temperatures using a mixture of 67.7 mol% CH4+32.3 mol% CO2 as the simulating acid natural gas and self-designed experimental apparatus. The designed initial pressures were 3.0 MPa, 3.5 MPa, 4.2 MPa, and 5.0 MPa. Operational temperatures were 1.42 ℃, 3.27 ℃, 5.48 ℃, and 7.45 ℃. Induction time, equilibrium time, formation rate were defined to evaluate kinetics index. Results showed that the concentration of CO2 in gas phase decreases as the initial pressure increases and operational temperature decreases. The formation rate and bulk volume of hydrate increase under the same conditions.

Key words: hydrate, formation kinetics, acid natural gas, evaluation indexes

摘要： 水合物的快速生成受诸多因素的影响，操作工况是其主要的影响因素之一。以67.7%CH4+32.3%CO2（摩尔分数）混合气为例模拟酸性天然气，采用自行设计的水合物动力学实验装置，分别对初始压力为3.0 MPa、3.5 MPa、4.2 MPa、5.0 MPa和实验温度分别为1.42 ℃、3.27 ℃、5.48 ℃、7.45 ℃时的水合物生成动力学进行实验研究。定义诱导期、平衡总耗时、生长速率为水合物动力学评价指标，指标通过分析水合物生成过程中的压力及气相组成变化得到，进而综合分析了操作工况对酸性天然气水合物生成动力学的影响。实验结果表明：初始压力越高，实验温度越低，水合物平衡时气相CO2的浓度越低，水合物的生成量和生长速率越大；此外，初始压力对体系诱导期影响不够显著，而操作温度的降低可以明显缩短体系诱导期。

关键词: 水合物, 生成动力学, 酸性天然气, 评价指标