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

描述：该奖项旨在支持阿拉巴马大学塔斯卡卢萨分校化学工程系的Stephen Ritchie博士和埃及开罗国家研究中心(NRC)的Elham El Zanati博士的合作研究。他们计划开展用于酸催化的功能化膜的研究。本研究旨在介绍一类基于功能化膜的新型固相酸催化剂的开发和基本认识。通过在膜的孔中对聚苯乙烯接枝进行磺化，将酸性基团添加到微滤膜中。通过苯乙烯的原位聚合将聚合物接枝固定在膜孔中。只需在膜上施加低压力梯度，就足以实现酸中心与反应物之间的良好接触。对流流动的重要性(仅在膜中可能)是使反应物能够完全和快速地到达酸性部位。实验工作将由初级科学家进行，包括本科生和研究生，重点是创造参与和传播结果的机会。智慧的优点：酸催化是化工过程工业中的一个关键的使能过程。传统的酸催化是在均相溶液中(无机酸)或通过与固相接触(例如，离子交换树脂)进行的。前者提供了很好的反应物对催化剂的可及性，但存在腐蚀和催化剂回收问题。固相催化剂的使用简化了催化剂的回收，减少了腐蚀，但也带来了新的问题，即由于运输以扩散为主，阻碍了催化剂的可获得性。这项研究将有助于更好地理解自由基聚合的接枝过程，并通过实验确定反应过程中的操作参数。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。对于后一种体系，功能化膜非常适合于克服Nafion分散在二氧化硅上的问题，在这种情况下，载体的可及性和失活会导致催化剂活性下降。更广泛的影响：拟议的工作将导致为化学加工工业开发一种新的酸催化剂。它对替代燃料，特别是生物燃料有有利的应用。当原料中含有游离脂肪酸时，酸催化的酯化反应对生物柴油的生产具有重要意义。这些脂肪酸不属于传统固相酸催化剂，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。这些材料还可以替代现有的用于烷基化反应的固相酸催化剂，这些固相酸催化剂存在可获得性低和失活的问题。这项工作将涉及两名美国本科生。美国P.I.和埃及的合作者将互访对方的实验室，这将扩大两国科学界的关系。该项目得到了美国-埃及联合基金计划的支持，该计划为两国的科学家和工程师提供开展这些合作活动的赠款。

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.