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

俄克拉荷马州州立大学的Paul Devlin教授得到化学系化学结构、动力学和机理计划的支持，研究笼形水合物的基本物理和化学性质。笼形水合物的形成，通常从液态水或冰，是如此缓慢，往往阻碍研究的速度和机制的过程。在先前奖项支持的研究中，最令人兴奋和有前途的发现是一种全新的水合物形成方法，可将反应时间缩短到亚秒级。一个通常缓慢的混合过程已被分流，通过使用一个全蒸汽的方法与组分客体分子充分混合水蒸气。脉冲进入冷室，蒸汽迅速冷凝成水溶液液滴，立即结晶为气溶胶的100%气体水合物颗粒。在目前的知识阶段仍然需要催化剂，但是在该项目的这一阶段中寻求的全蒸气方法的进步可能有助于以下方面的技术发展：a）从甲烷水合物的丰富海洋沉积物矿床中生产甲烷，和B）在大大降低的压力下浓缩/储存作为水合物客体的气体，例如甲烷和CO2。例如，已经表明，包含CO2的潮湿空气是适合于气体水合物的全蒸气形成的蒸气混合物，只要包含催化剂。笼形物/气体水合物最简单地描述为水分子的主体冰状晶格，其具有结合的小笼，所述小笼用作容纳小有机或无机客体分子的分子大小的陷阱。由于在自然界中异常丰富，并具有重大的环境和技术影响，它们在过去世纪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，但对它们参与氢键化学及其形成机制知之甚少。在这个项目中，Devlin教授和他的本科生研究助理将致力于开发气体水合物形成和控制的方法，这将促进气体水合物科学在能源工业和环境中控制二氧化碳和甲烷等气体的应用。

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.