Measurement of the Hydrate Phase via Raman and NMR Spectroscopy

CTS-9634899 斯隆，E. D。 科罗拉多矿业学院 项目摘要 通过拉曼光谱和核磁共振光谱测量水合物相结构和组成，提出了一种新的水合物实验的最先进的原型。 在这项工作中，我们建议做以下六件事：1。 利用核磁共振技术测量了sI水合物中129碳和13碳（甲烷）的相对笼占有率，并与Ripmeester和我们的拉曼实验数据进行了对比。 使用通过NMR和拉曼方法测量的水化数和空穴占据来评估货车德瓦尔斯和Platteeuw统计理论。 使用我们现有的400 MHz NMR和新的拉曼仪器确定水合物结构之间的固相转变动力学（例如sI到sH），4。 设计、制造并测试一种新型的装置，该装置将拉曼装置（用于测量固体）与常规的宏观相平衡仪器相结合。 评估拉曼光谱用于动力学水合物研究的可行性，以及6. 评估光纤拉曼装置作为在线水合物监测器的可行性。 这项工作将产生三大影响： 1. 水合物的结构实际上从来没有被测量过，而是被预测过。 有多个 预测不正确的水合物结构的实例。 与至少 三种常见的水合物结构，不正确的结构（和相关的地层 条件）比通常实现的更频繁地被预测。 拟议 工作将证明如何纠正这一问题。 2. 水合物相组成（空穴占据、主客体和主客体 比率）也是预测的而不是测量的。 然而，这种测量是 由于水合物的形成，需要校正现有的热力学模型 条件不仅取决于结构，而且取决于相组成。 3. 光纤技术的出现使水合物相的测量成为可能 与宏观测量的同时， 均衡 这项技术不仅有可能改变水合物的方法， 在实验室中的测量，它也有可能被用作在线 监测工艺流中水合物的形成。 到目前为止，工业界只有压力 用于确定管道中水合物的生成和生长。 我们现在应该在实验室进行这项工作，因为： 1. 实验验证了水合物的拉曼测量概念 sI、sII和sH结构和客体组成。 2. 最近的NSF匹配基金设备赠款提供了一个400兆赫 NMR仪器能够进行固体或液体测量。 3. 我们有专门人员来监督这项工作。 Ben Bloys先生（阿科）将作为我们10家公司组成的联合体的工业联络人参与该项目。 鲍勃·布拉斯博士 （美国地质勘探局）将提供拉曼专业知识和设备的可用性。 John Ripmeester博士将担任兼职教授，负责监督拟议的NMR工作。

CTS-9634899 Sloan, E.D. Colorado School of Mines PROJECT SUMMARY A new state-of-the-art protoype for hydrate experiments is proposed by measurements of the hydrate phase structure and composition, using Raman and NMR spectroscopy. In this work we propose to do the following six things: 1. Measure the relative cage occupancies of 129Xe and 13C (methane) in sI hydrate via NMR, for calibration with data of Ripmeester and our Raman work, 2. Use the hydration numbers and cavity occupation measured via NMR and Raman methods to assess the van der Waals and Platteeuw statistical theory, 3. Determine the kinetics of solid phase transitions between hydrate structures( e.g. sI to sH ) using our existing 400 MHz NMR, and a new Raman instrument, 4. Design, fabricate, and test a new type of apparatus which combines a Raman devices (to measure the solid) with a regular macroscopic phase equilibria instrument, 5. Assess the viability of Raman spectroscopy for kinetic hydrate studies, and 6. Assess the viability of a Fiber Optics Raman device as an in-line hydrate monitor. The work will have three major impacts: 1. The hydrate structure is virtually never measured but predicted. There are multiple instances in which the incorrect hydrate structure has been predicted. With at least three common hydrate structures, the incorrect structure(and associated formation conditions) is predicted more frequently than commonly realized. The proposed work will demonstrate how this problem may be corrected. 2. The hydrate phase composition( cavity occupation, guest-to-host and guest-to-guest ratios) is also predicted rather than measured. However, such measurements are necessary to correct the existing thermodynamic model since hydrate formation conditions depend not only on structure but also on the phase composition. 3. The advent of Fiber Optics technology enables measurement of hydrate phase composition simultaneously with the macroscopic measurements of phase equilbria. This technology not only has the potential to change the method of hydrate measurements in the laboratory, it also has the potential to be used as an in-line monitor for hydrate formation in process streams. To date industry only has pressure drop to determine the initiation and growth of hydrate in a pipeline. The proposed work should be done now in our laboratory because: 1. We have experimentally validated the concept of the Raman measurement of hydrate structure and guest composition for sI, sII, and sH. 2. A recent NSF matching-funds equipment grant has provided a 400 MHz NMR instrument capable of solid or liquid measurements. 3. We have expert personnel available to supervise the work. Mr. Ben Bloys (ARCO) will be industrial liaison with our consortium of 10 companies to the project. Dr. Bob Burruss. (USGS) will provide Raman expertise and apparatus availability. Dr. John Ripmeester will act as an adjunct professor in supervising the proposed NMR work.