U.S.-Egypt Cooperative Research: Functionalized Membranes for Acid Catalysis

该奖项旨在支持阿拉巴马州塔斯卡卢萨市阿拉巴马大学化学工程系的Stephen Ritchie博士和埃及开罗国家研究中心（NRC）的Elham El Zanati博士的一项合作研究。他们计划进行酸催化功能化膜的研究。本研究旨在解决一类基于功能化膜的新型固相酸催化剂的发展和基本认识。通过在微滤膜孔中接枝聚苯乙烯的磺化，将酸基团添加到微滤膜上。通过苯乙烯的原位聚合，将聚合物接枝固定在膜孔中。只需在膜上施加一个低压梯度就足以实现酸位和反应物之间的良好接触。对流流动（仅在膜中可能）的重要性在于它使反应物能够完全和快速地到达酸位点。实验工作将由包括本科生和研究生在内的初级科学家进行，重点是为参与和传播结果创造机会。智力优势：酸催化是化工过程中一个关键的使能过程。传统的酸催化是在均相溶液（无机酸）中或通过与固相（如离子交换树脂）接触进行的。前者为催化剂提供了良好的反应物可及性，但存在腐蚀和催化剂回收的问题。固相催化剂的使用简化了催化剂的回收，减少了腐蚀，但由于传输主要由扩散控制，引入了可及性受阻的新问题。这项研究将有助于更好地理解自由基聚合的接枝过程和反应过程中操作参数的实验确定。感兴趣的反应包括乙酸乙酯和异辛烷的酯化和烷基化反应。对于后一种系统，功能化膜非常适合克服分散在二氧化硅上的Nafion所遇到的问题，在这种情况下，载体的可及性和失活性会导致催化剂活性的降低。更广泛的影响：拟议的工作将导致开发一种新的酸性催化剂用于化学过程工业。它在替代燃料，特别是生物燃料方面有有益的应用。当原料中含有游离脂肪酸时，酸催化酯化反应对生物柴油的生产具有重要意义。这些脂肪酸可以从传统的固相酸催化剂中排除，并且在均相溶液中容易发生副反应。催化膜将是克服这些问题的一种方法，并可能对生物柴油和其他替代燃料的大规模生产产生重大影响。这些材料也可以提供替代现有的固体相酸催化剂的烷基化，其遭受低接近性和失活。这项工作将涉及两名美国本科生。美国私家侦探和埃及合作者将互访彼此的实验室，这将扩大两国科学界之间的关系。该项目得到了美国-埃及联合基金项目的支持，该项目向两国的科学家和工程师提供赠款，以开展这些合作活动。

0612267RitchieDescription: This award is to support a cooperative research by Dr. Stephen Ritchie, Department of Chemical Engineering, University of Alabama, Tuscaloosa, Alabama and Dr. Elham El Zanati, National Research Center (NRC), Cairo, Egypt. They plan to conduct research on Functionalized Membranes for Acid Catalysis. The research is to address the development and fundamental understanding of a new class of solid-phase acid catalysts based on functionalized membranes. Acid groups are added to a microfiltration membrane by sulfonation of polystyrene grafts in the pores of the membrane. Polymer grafts are immobilized in the membrane pores by in-situ polymerization of styrene. Simple application of a low pressure gradient across the membrane is sufficient to achieve excellent contact between acid sites and the reactants. The importance of convective flow (only possible in the membrane) is that it enables the complete and rapid accessibility of reactants to acid sites. Experimental efforts will be performed by junior scientists including undergraduate and graduate students, with an emphasis of creating opportunities for Involvement and dissemination of results. Intellectual Merit: Acid catalysis is a critical enabling process in the chemical process industry. Conventional acid catalysis is performed in homogeneous solution (mineral acids) or by contact with a solid phase (e.g., ion exchange resins). The former offers excellent reactant accessibility to the catalyst, but suffers from problems with corrosion and catalyst recovery. The use of solid phase catalysts simplifies catalyst recovery with less corrosion, but introduces the new problem of hindered accessibility because transport is dominated by diffusion. This research should lead to a better understanding of the grafting process with polymerization by free radical processes and experimental determination of operating parameters during reaction. Reactions of interest include esterification and alkylation for ethyl acetate and isooctane, respectively. For the latter system, functionalized membranes are ideally suited to overcome problems seen with Nafion dispersed on silica, where accessibility and deactivation by the support result in degradation of catalyst activity. Broader Impact: The proposed work will result in the development of a new acid catalyst for the chemical process industry. It has beneficial applications for alternative fuels, and biofuels in particular. Acid catalyzed esterification is important for the production of biodiesel when the feedstock contains free fatty acids. These fatty acids can be excluded from conventional solid phase acid catalysts, and are susceptible to side reactions in homogeneous solution. A catalytic membrane would be a way to overcome these problems, and may have a major effect on the large scale production of biodiesel and other alternative fuels. These materials may also offer an alternative to existing solid phase acid catalysts for alkylations, which suffer from low accessibility and deactivation. The work will involve two US undergraduate students. There will be exchange of visits by the US P.I. and the Egyptian collaborators to each others laboratories and this should expand relations between the scientific communities in both countries.This project is being supported under the US-Egypt Joint Fund Program, which provides grants to scientists and engineers in both countries to carry out these cooperative activities.