天然气水合物是潜在的清洁能源,储量巨大.高效开发利用天然气水合物,具有重要意义.微波加热作用速度快,应用比较灵活,有希望用于开采各类型天然气水合物资源及水合物储运技术.实验研究了2450MHz、不同微波功率下天然气水合物的形成/分解过程,初步分析了微波对天然气水合物相平衡的影响,并在van der Waals-Platteeuw模型的基础上进行了计算.结果表明:一定功率的微波可降低水合物形成的过冷度和诱导时间,20W微波状况下,过冷度减小约3℃,诱导时间由4.5h缩短到1.3h;发现微波可使水合物快速分解,随着水合物的分解,产生的分解水加速了水合物的分解,分解水与微波具有协同作用;相同压力下,微波可提高水合物的相平衡温度.天然气水合物分解过程中各组分介电性质的差异造成了反应体系在分解过程中存在显著的温度差异,微波加热分解水合物存在多种因素的共同作用.
Natural gas hydrate (NGH) reservoirs have been considered as a substantial future clean energy re-source and how to recover gas from these reservoirs feasibly and economically is very important. Mi-crowave heating will be taken as a promising method for gas production from gas hydrates for its ad-vantages of fast heat transfer and flexible application. In this work, we investigate the formation /decomposition behavior of natural gas hydrate with different power of microwave (2450MHZ), pre-liminarily analyze the impact of microwave on phase equilibrium of gas hydrate,and make calculation based on van der Waals-Platteeuw model. It is found that microwave of a certain amount of power can reduce the induction time and sub-cooling degree of NGH formation, e.g., 20W microwave power can lead to a decrease of about 3℃ in sub-cooling degree and the shortening of induction time from 4.5 hours to 1.3 hours. Microwave can make rapid NGH decomposition, and water from NGH decomposi-tion accelerates the decomposition of NGH with the decomposition of NGH. Under the same pressure, microwave can increase NGH phase equilibrium temperature. Different dielectric properties of each composition of NGH may cause a distinct difference in temperature in the process of NGH decomposi-tion. Therefore, NGH decomposition by microwave can be affected by many factors.
