GOALI: Collaborative Research: Fundamental studies of water - hydrocarbon condensation

目标：合作研究：水-碳氢化合物凝结的基础研究

• 批准号: 1033387
• 负责人: Gerald Wilemski
• 金额: $ 20.63万
• 依托单位: Missouri University of Science and Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1033387&HistoricalAwards=false
• 关键词: GOALI; Collaborative; Research; Fundamental; studies

Abstract Currently, natural gas supplies ~23% of U.S. energy needs. In addition to CH4, raw natural gas contains water, higher hydrocarbons, and other substances that must be removed before the gas is transported and used. For off-shore wells, treatment near the wellhead is critical to prevent clathrates from forming and plugging the pipeline as gas flows to the mainland. The raw gas is normally treated by adding chemicals or reducing its dew point, but standard processing equipment is often large and requires manned platform operation. An alternative approach is to use supersonic natural gas separators that (1) cool the gas in a supersonic expansion to induce droplet formation and growth, (2) separate the droplets from the gas, and, (3) recompress the dried gas using a diffuser to minimize pressure losses. These separators are smaller than traditional process equipment, have no moving parts, and require no chemicals. Thus, they are suited for both off-shore and sub-sea applications. Worldwide, three of these devices are now in commercial operation. Twister BV, the industrial partner for this proposal, is at the forefront of developing and implementing this technology. As these devices are adopted, however, critical questions remain regarding droplet formation and growth in these complex vapor mixtures, and these questions are related to the structure of the droplets. Intellectual Merit: With an overarching goal of improving the efficiency of natural gas production, this proposal examines droplet formation, growth, and structure in highly non-ideal water hydrocarbon systems under conditions that mimic those found in the supersonic separators. The experimental program will characterize the condensation process in supersonic nozzles, at Mach numbers comparable to the real separators, using pressure measurements and spectroscopy. The resultant aerosols will be characterized using small angle x-ray and/or neutron scattering. The theoretical program will focus on understanding droplet structure, formation and growth rates as a function of the key parameters, i.e., the vapor phase compositions and temperature. Combining the experimental results with the theoretical calculations and detailed modeling will result in more robust descriptions of multicomponent droplet formation and growth that can then be incorporated into the computational fluid dynamics codes used to describe and optimize the performance of supersonic separators. This novel application of computer simulation techniques and density functional theory and of small angle neutron and x-ray scattering experiments is helping transform the field of aerosol science by enabling the solution of problems that previously defied investigation. Broader Impacts: In a broader context, this work is directed toward improving the energy efficiency of natural gas production. In addition to their relevance to the domestic natural gas industry, as well as to Twister BV, the results stemming from this work are of interest to other researchers in nucleation, aerosol science, and cloud and atmospheric physics. In the area of education and training, this project will provide a rich, highly interdisciplinary research environment for all students and will incorporate a unique international experience for graduate students. Participation in the research by undergraduate students, particularly from minority and underrepresented groups, will be fostered. As an important outreach activity, table top diffusion cloud chambers will be built so that students and teachers can visualize cloud formation in the classroom, a process that is of great interest in elementary and high school education but is not easily realized.

目前，天然气供应美国能源需求的23%。除甲烷外，天然气原料还含有水、高级烃和其他物质，这些物质必须在天然气运输和使用前去除。对于海上威尔斯井，井口附近的处理是至关重要的，以防止形成笼形物和堵塞管道，因为气体流向大陆。通常通过添加化学品或降低其露点来处理原料气，但标准处理设备通常很大，需要有人操作的平台。另一种方法是使用超音速天然气分离器，其（1）在超音速膨胀中冷却气体以诱导液滴形成和生长，（2）将液滴与气体分离，以及（3）使用扩散器再压缩干燥的气体以使压力损失最小化。这些分离器比传统的工艺设备更小，没有移动部件，不需要化学品。因此，它们适用于近海和海底应用。在世界范围内，其中三个设备现已投入商业运营。Twister BV是该提案的工业合作伙伴，处于开发和实施该技术的最前沿。然而，随着这些装置的采用，关于这些复杂蒸汽混合物中的液滴形成和生长的关键问题仍然存在，并且这些问题与液滴的结构有关。智力优势：以提高天然气生产效率为首要目标，本提案研究了在模仿超声分离器中发现的条件下高度非理想水烃系统中的液滴形成、生长和结构。实验计划将利用压力测量和光谱学来表征超音速喷管中的冷凝过程，马赫数与真实的分离器相当。将使用小角度X射线和/或中子散射来表征所产生的气溶胶。理论课程将侧重于了解液滴结构，形成和增长率作为关键参数的函数，即，气相组成和温度。将实验结果与理论计算和详细建模相结合，将导致多组分液滴形成和生长的更鲁棒的描述，然后可以将其纳入用于描述和优化超音速分离器性能的计算流体动力学代码中。计算机模拟技术和密度泛函理论以及小角度中子和X射线散射实验的这种新颖应用有助于通过解决以前无法调查的问题来改变气溶胶科学领域。更广泛的影响：在更广泛的背景下，这项工作旨在提高天然气生产的能源效率。除了与国内天然气工业以及Twister BV的相关性外，这项工作的结果还引起了核化，气溶胶科学以及云和大气物理学的其他研究人员的兴趣。在教育和培训领域，该项目将为所有学生提供丰富的，高度跨学科的研究环境，并将为研究生提供独特的国际经验。将促进本科生，特别是少数民族和代表性不足群体的本科生参与研究。作为一项重要的推广活动，将建造桌面扩散云室，使学生和教师能够在课堂上可视化云的形成，这是一个在小学和中学教育中非常感兴趣但不容易实现的过程。