相变浆液中甲烷水合物的生成过程强化

Enhancement of methane hydrate formation process in phase change slurry

利用相变材料(PCM)正十四烷的固液相变过程,吸收甲烷水合释放的热量,实现了直接换热强化水合过程的目的。正十四烷与水混合制成相变乳液(PCE),经冷却后形成浆液。在半间歇水合器中,测定并计算了甲烷水合物在此浆液中的收率和生成速率。为了提高计算的准确性,设计了一套PVT装置,通过减压法实验测定了低温条件下甲烷在正十四烷中的溶解度。实验结果表明:低温条件下,甲烷在正十四烷中的溶解度与压力基本呈线性关系;相比于间接传热方式下的水合过程,相变浆液中甲烷水合物收率及生成速率得到了有效提升。

The phase change emulsion（PCE） containing phase change material（PCM） of n-tetradecane was used to directly absorb heat of the hydration by the solid-to-liquid phase change of n-tetradecane. Once n-tetradecane in PCE was solidified in the hydrator, the PCE would convert to slurry. The impacts of different pressures from 5.0 to 6.28 MPa on the yield of methane hydrate and hydration rate in the slurry at the temperature 277.6 K were researched at a semi-batch hydrator. Considering the influence of methane dissolution in n-tetradecane on the hydration process, a PVT apparatus to measure the solubility of methane in liquid n-tetradecane was designed, and a more precise calculation process was established to describe the methane hydration. The results showed that：at low temperature conditions, the solubility of methane in liquid n-tetradecane distributed linearly versus pressure, and the methane hydrate formation process was intensified significantly compared to indirect heat removal hydration.