文摘
Storage capacities, formation rates, and induction periods of methane hydrates in slurries of solid n-tetradecane, which is a phase change material (PCM), were investigated experimentally in a semibatch hydrator with a stirrer. The hydrations were carried out at an initial temperature of 277.1 K, which was slightly lower than the melting point of n-tetradecane in a slurry; the stirring rate was 800 rpm, and the experimental pressures were in the range of 5.00鈥?.28 MPa. The emulsion of PCM was prepared using a high-speed disperser and then cooled to solidify the PCM droplets in an oil-in-water (O/W) emulsion. The highest storage capacity of 158.7 V/V was found at 5.26 MPa, and the corresponding hydration time was only 78 min. The hydration rates divided into three stages: a constant speed was observed initially, followed by a steep increase, and a slowing in the final step. The maximum hydration rate was 0.0096 molCH4/(molH2O min) at 5.26 MPa. The induction time of hydration was reduced largely to a few minutes. Therefore, the fast formation rate and short induction time led to free water being trapped in the hydrate and much higher pressures would make the storage capacity smaller. Therefore, the advantage of our method is improving heat transfer during hydration, which results in a fast hydration rate and high storage capacity. On the other hand, one disadvantage is that the method is somewhat complex.