GOALI: Fundamental Studies of Transport of Mixtures in Microporous Membranes under Supercritical Conditions

目标：超临界条件下微孔膜中混合物传输的基础研究

• 批准号: 9907481
• 负责人: Muhammad Sahimi
• 金额: $ 32.04万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-15 至 2004-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9907481&HistoricalAwards=false
• 关键词: GOALI; Fundamental; Studies; Transport; Mixtures

ABSTRACT This project is a collaborative academic/industrial research (GOALI) project to investigate the transport of supercritical hydrocarbon/CO2 mixtures in microporous carbon molecular-sieve membranes. The study will proceed in two parts: (1) preparation and experimental characterization of the membrane along with computational modeling of the evolution of its structure during synthesis; and (2) measurement and simultaneous computer simulation of the sorption and transport of supercritical mixtures within the membranes. The systems under study are supercritical mixtures composed of CO2 and one or more of the following hydrocarbons, butane, isobutane, benzene, and toluene. These hydrocarbons were selected to represent typical aliphatic and aromatic compounds and to permit exploration of factors such as molecular shape. Non-equilibrium grand canonical molecular dynamics (NEGCMD) simulation techniques are being used to study the transport of these mixtures in microporous materials. The objective of the molecular calculations is to relate and correlate the membrane's molecular structure with experimentally observed transport properties and separation efficacy. The long-term goal is to achieve reliable engineering and design of improved materials for molecular sieves and catalytic-membrane reactors. The results of these studies will contribute to applications such as the regeneration of adsorbents by supercritical CO2 and the use of membranes under supercritical conditions. Carbon molecular- sieve membranes are capable of withstanding the high pressures and temperatures associated with supercritical conditions. They can be prepared with well-controlled porosity and pore size and a very narrow pore-size distribution. Understanding the factors determining the ability of these materials to effect separations of supercritical mixtures based on differences in molecular mobility within the membranes will promote their use in the removal of various contaminants from water, sludges, soils, spent catalysts, and adsorbents like granular activated carbon. The ability to remove solutes continuously from supercritical carbon dioxide would produce significant reductions in operating costs compared with the energy-intensive expansion/re-compression cycle normally used to separate solutes from supercritical solvents.

摘要该项目是一个协作学术/工业研究（Goali）项目，旨在调查微孔碳分子膜膜中超临界碳氢化合物/二氧化碳混合物的运输。该研究将分为两个部分：（1）膜的制备和实验表征以及合成过程中其结构演变的计算建模； （2）对膜内超临界混合物的吸附和运输的测量和计算机模拟。 所研究的系统是由二氧化碳和以下一个或多个碳氢化合物组成的超临界混合物，即丁烷，异丁烷，苯和甲苯。 选择这些烃代表典型的脂肪族和芳香化合物，并允许探索诸如分子形状之类的因素。 非平衡大典型分子动力学（NEGCMD）模拟技术用于研究这些混合物在微孔材料中的运输。 分子计算的目的是将膜的分子结构与实验观察到的转运特性和分离功效相关联。 长期目标是实现可靠的工程和设计用于分子筛和催化膜反应器的改进材料。 这些研究的结果将有助于应用，例如超临界二氧化碳对吸附剂的再生以及在超临界条件下使用膜的应用。 碳分子晶状膜能够承受与超临界条件相关的高压和温度。 它们可以以良好的控制孔隙度和孔径和非常狭窄的孔径分布来制备。 理解决定这些材料在膜内分子迁移率差异实现超临界混合物分离能力的因素，将促进它们在去除水，泥浆，土壤，消费催化剂以及像颗粒状活性碳中的吸附剂中的各种污染物中的使用。 与通常用于将溶质与超临界溶剂分离的能源密集型扩张/重压周期相比，从超临界二氧化碳中连续去除溶质的能力将显着降低运营成本。