Spatio-Temporal Phenomena During Adsorption and Reaction in Hydrocarbon Traps

PI：哈罗德，迈克尔研究所：休斯顿大学提议编号：1067709题目：在烃类捕捉器中的吸附和反应过程中的时空现象PI计划对贵金属分子筛催化剂在瞬时升温和低温操作期间同时捕获和氧化烃类混合物进行现场实验测量和模拟。这些信息将用于设计符合新的严格排放限制的柴油氧化催化剂(DOC)反应器配置。中心活动将是研究双功能捕集催化剂的几何和组成性质对模型排气成分的瞬时氧化的影响。这项研究将确定跨越顺序、分段和双层设计的几种不同催化剂体系结构的相对性能。利用一套现场实验技术，PI将跟踪这类快速、放热、瞬时催化氧化的时空特征。这些资料将共同提供有关低温碳氢化合物捕集和氧化过程中耦合的浓度和温度前沿的详细信息。化学反应器中的分布式温度扫描测量将提供以前无法获得的数据。1.在铂/钯/沸石-β-Al_2O_3催化剂上进行了烃类捕集和氧化本征动力学研究和产物时间分析(TAP)反应。2.利用空间分辨质谱仪测量了模型催化剂上碳氢化合物捕集和氧化过程中反应物种的时间浓度分布。3.利用分布式温度传感扫描波长干涉仪(DTS-SWI)测量了涂层整体柱在油气捕集和氧化过程中多个通道内的时空温度分布。4.利用空间分辨质谱仪、扫描波长干涉仪和积分漫反射红外光谱仪进行综合实验，绘制模型油气捕集和氧化反应体系的时空行为图。5.建立了一个模拟油气圈闭和氧化的时空模型，该模型反映了模型反应体系中观察到的主要趋势。6.在氧化铝载体上合成含贵金属(铂、钯)和烃类吸附剂(沸石-贝塔)的混合层和双层洗涤涂层催化剂。7.利用实际的柴油车尾气进行验证实验。该项目的智力价值在于促进了对柴油氧化催化剂(DOC)这一具有实际意义的时变催化过程的可靠性问题和优化操作的认识和理解。这一知识将适用于其他催化反应器的瞬时运行，如填充床。这项研究将有助于开发碳氢化合物捕集器的预测吸附反应器模型，设计关键实验，并确定各种反应器结构在瞬变操作下的最佳性能。在冷启动和低温运行期间实现排气部件的氧化是一项艰巨的技术挑战。私人投资促进机构期望研究所产生的理解和洞察力将导致一种新的催化剂设计和操作和控制策略方法，以最大限度地减少来自DOC的污染物的突破。更广泛的影响是开发新的实验方法来确定瞬时催化反应器的时空特征。这项研究将向反应工程界介绍新的实验方法的应用，包括空间分辨质谱学、分布式温度传感和产物的同位素时间分析。研究成果将在石油化工和环境行业从业者使用的存档期刊中传播。PIS还将向科学界提供反应堆代码，并将研究结果纳入密歇根大学的研究生课程。该项目将作为一个技术平台，吸引高中生对工程科学的兴趣，并吸引本科生进行研究生研究。这将通过本科生参与该项目和为高中理科教师提供暑期实习来实现。

PI: Harold, Michael Institution: University of HoustonProposal Number: 1067709Title: Spatio-Temporal Phenomena During Adsorption and Reaction in Hydrocarbon TrapsThe PIs plan to conduct in situ experimental measurements and modeling of simultaneous trapping and oxidation of hydrocarbon mixtures on precious metal based zeolite catalysts during transient warmup and low temperature operation. The information will be used for the design of a diesel oxidation catalyst (DOC) reactor configuration that satisfies new stringent emission limits. The central activity will be to study the effects of the geometric and compositional properties of the bi-functional trapping catalyst on the transient oxidation of model exhaust components. The research will determine the relative performance of several different catalyst architectures spanning sequential, segmented, and dual layer designs. Using a set of in situ experimental techniques the PIs will follow the spatio-temporal features of this class of fast, exothermic, transient catalytic oxidations. These will collectively provide detailed information about coupled concentration and temperature fronts during low temperature hydrocarbon trapping and oxidation. The distributed temperature scanning measurements in a chemical reactor will provide data that could not be previously obtained. The work to be done includes: 1. Carry out intrinsic kinetics studies of hydrocarbon trapping and oxidation in a bench-flow reactor and temporal analysis of products (TAP) reactor on Pt/Pd/zeolite-Beta /ã-Al2O3 catalysts. 2. Use spatially-resolved mass spectrometry to measure the temporal concentration profiles of reacting species during hydrocarbon trapping and oxidation on the model catalysts. 3. Use distributed temperature sensing with swept-wavelength interferometry (DTS-SWI) to measure the spatio-temporal temperature profile inside several channels of a washcoated monolith during hydrocarbon trapping and oxidation. 4.Conduct comprehensive experiments utilizing spatially-resolved mass spectrometry, swept-wavelength interferometry, and integral diffuse-reflectance IR spectroscopy to map spatial and temporal behavior of model hydrocarbon trapping and oxidation reaction system. 5. Develop a spatio-temporal model to simulate hydrocarbon trapping and oxidation that captures the main trends observed in the model reaction system. 6.Synthesize mixed-layer and dual-layer washcoated catalysts containing the precious metal (Pt, Pd) and hydrocarbon adsorbent (zeolite-Beta) on an alumina support. 7. Carry out validation experiments using actual diesel vehicle exhaust. The intellectual merit of this project is to advance knowledge and understanding of reliability issues and optimal operation of a time-varying catalytic process of practical significance, the diesel oxidation catalyst (DOC). That knowledge will be applicable to transient operation of other catalytic reactors such as packed beds. The research will enable development of predictive adsorptive reactor models of the hydrocarbon trap, design of critical experiments, and identification of optimal performance of various reactor configurations under transient operation. Enabling the oxidation of the exhaust components during the cold start and low temperature operation is a demanding technological challenge. The PIs expect that the understanding and insight generated by the study will lead to a novel catalyst designs and operation and control strategies approach that minimize the breakthrough of pollutants from the DOC. The broader impact is the development of novel experimental methodologies to determine spatio-temporal features of transient catalytic reactors. The research will introduce to the reaction engineering community the application of new experimental methods, including spatially resolved mass spectrometry, distributed temperature sensing, and isotopic temporal analysis of products. Research findings will be disseminated in archived journals utilized by practitioners in the petrochemical and environmental industries. The PIs will also provide reactor codes to the scientific community and will incorporate findings from the research into graduate level courses at UH. The project will be used as a technology platform to attract interest in engineering science among high school students and graduate research among undergraduate students. This will be accomplished through the involvement of undergraduate students in the project, and a summer internship offered to high school science teachers.