Exploring the Physical Chemistry of the Catalysis-Based All-Vapor Instant Formation of Gas Hydrates at Moderate P and T (180-220 K)

俄克拉荷马州立大学的保罗·德夫林教授得到了化学部化学结构、动力学和机理计划的支持，研究笼状水合物的基本物理和化学性质。笼状水合物的形成非常缓慢，通常是从液态水或冰中形成的，这往往阻碍了对这一过程的速率和机制的研究。在之前获奖的研究中，最令人兴奋和最有希望的发现是一种全新的水合物形成方法，它将反应时间缩短到亚秒级。通过使用全蒸气方法，将组分的客体分子完全与水蒸气混合，避免了通常缓慢的混合过程。进入冷室的蒸汽迅速凝结成水溶液液滴，这些水滴立即结晶成100%的气溶胶气体水合物颗粒。在目前的知识阶段仍然需要催化剂，但在该项目的这一阶段寻求的全蒸汽法的进展可能有助于a)从丰富的甲烷水合物的海洋沉积物沉积物中生产甲烷，以及b)以大大降低的压力浓缩/储存作为水合物客体的甲烷和二氧化碳等气体。例如，已经证明，在包括催化剂的情况下，包括二氧化碳在内的潮湿空气是一种适合于气体水合物的全蒸汽形成的蒸汽混合物。笼状/气体水合物最简单地描述为带有结合的小笼子的主体冰状水分子晶格，这些小笼子充当分子大小的陷阱，容纳小的有机或无机客体分子。由于它们在自然界的异常丰富及其对环境和技术的重大影响，在过去的一个世纪里，它们一直是许多研究的对象。人们对它们的存在和物理性质知之甚少，对它们参与氢键化学和它们的形成机制知之甚少。在这个项目中，Devlin教授和他的本科研究助理将致力于开发天然气水合物的形成和控制方法，以促进天然气水合物在能源行业和环境中控制二氧化碳和甲烷等气体的科学应用。

Prof. Paul Devlin of Oklahoma State University is supported by the Chemical Structure, Dynamics and Mechanisms Program of the Chemistry Division to study the basic physical and chemical properties of clathrate hydrates. Clathrate hydrate formation, typically from liquid water or ice, is so slow as to often discourage studies of the rates and mechanisms of the process. The most exciting and promising discovery from research supported under prior awards is a completely new method of hydrate formation that reduces the reaction time to the subsecond scale. A generally slow mixing process has been shunted by using an all-vapor methodology with component guest molecules fully mixed with water vapor. Pulsed into a cold chamber the vapor quickly condenses to aqueous solution droplets that instantly crystallize as 100% gas-hydrate particles of an aerosol. A catalyst is still required at the current stage of knowledge, but advances in the all-vapor method sought in this phase of the project may aid technological developments in a) the production of methane from abundant ocean-sediment deposits of methane hydrate, and b) the concentration/storage of gases such as methane and CO2 as hydrate guests at greatly reduced pressures. It has been shown, for example, that humid air including CO2 is a vapor mixture suited to the all-vapor formation of a gas hydrate provided a catalyst is includedA clathrate/gas hydrate is most simply described as a host ice-like lattice of water molecules with incorporated small cages that serve as molecule-sized traps holding small organic or inorganic guest molecules. Because of an exceptional abundance in nature and their significant environmental and technological implications, they have been an object of many investigations over the past century. Much is known about their occurrence and physical properties; less about their participation in H-bond chemistry and the mechanisms of their formation. In this project, Prof. Devlin and his undergraduate research assistants will pursue the development of methods of gas-hydrate formation and control that will facilitate gas -hydrate science applications for controlling gases such as carbon dioxide and methane in the energy industry and the environment.