Career: Catalyst-Directed Resource from Waste Polymers

摘要 CTS-9623741 催化剂导向的资源回收是将聚合物废料转化为高价值产品如燃料和石化产品的一种有前途的技术。 但缺乏 全面的知识库限制了其应用。 本研究旨在开发一种严格的，以科学为基础的方法，从聚合物废物中回收高价值的产品，同时使用实验和理论。 该实验项目的重点是开发 新的接触模式，以提高聚合物-催化剂的相互作用和对识别 优化催化剂参数，提高产品的价值。 实验工作的补充，利用机理建模和计算量子化学的理论研究，提供有关控制反应的基本原理的信息。 通过实验研究，确定了提高废聚合物中有价值产品回收率的可行策略。 超细颗粒或均相催化剂和液体超强酸的使用旨在通过利用聚合物的固有空隙体积来克服聚合物熔体渗透固体催化剂时遇到的固有扩散限制。 然而，传统的聚合物-催化剂接触模式具有允许聚合物在现有加工单元中加工的优点。 因此，多相催化剂的相关设计参数，即，酸度//碱度和结构进行了检查。实验工作的补充，旨在先验预测的给定聚合物原料和催化剂配方的降解特性的理论研究。 从实验研究中积累的数据库提供了一般的定性规则，作为制定预测，定量机制模型的起点。 通常，聚合物趋向于特定降解产物的趋势归因于三个因素：（1）聚合物主链中的键强度，（2）叔氢的存在，和（3）取代基键的相对强度。 这些定性规则中的每一个都使用结合机械建模和计算量子化学的方法进行定量研究。 已经进行了初步的工作，以证明机械建模的应用，以量化的趋势，不同的聚合物热降解为单体。 制定了一项将研究和教学联系起来的教育计划，以教育化学工程专业的学生在不断变化和日益创业的环境中处理复杂的问题。该计划的核心组成部分是（1）开发通用制造模块，将理论概念与真实的世界过程联系起来，（2）将计算量子化学引入本科课程，用于属性估计，以及（3）通过个人和团队的口头和书面演示来发展沟通技能。 每一个都是一个通用的组成部分，可以纳入整个课程。

ABSTRACT CTS-9623741 Catalyst-directed resource recovery is a promising technology for the conversion of polymeric waste materials into high-valued products such as fuels and petrochemicals. However, the lack of a comprehensive knowledge base has limited its application. This research aims at developing a rigorous, science-based methodology for the recovery of high-valued products from polymeric waste using both experiment and theory. The experimental program focuses on the development of novel contacting patterns to enhance the polymer-catalyst interaction and on the identification of optimal catalyst parameters that enhance the value of the products afforded. The experimental work is complemented by a theoretical study exploiting mechanistic modeling and computational quantum chemistry to provide information about the controlling reaction fundamentals. Promising strategies for improved recovery of valuable products from waste polymer have been identified and are investigated through experiment. The use of ultra-fine particle or homogeneous catalysts and liquid superacids aims to overcome the inherent diffusional limitations encountered in a polymer melt penetrating a solid catalyst by exploiting the intrinsic void volume of the polymer. However, traditional polymer-catalyst contacting patterns have the advantage of allowing the polymers to be processed in existing processing units. Therefore, relevant design parameters of heterogeneous catalysts, i.e., acidity//basicity and structure, are examined. The experimental work is complemented by a theoretical study aimed at a priori prediction of the degradation characteristics of a given polymer feedstock and catalyst formulation. The database amassed from experimental studies provides general qualitative rules that serve as a starting point for formulating a predictive, quantitative mechanistic model. In general, the tendency of a polymer toward particular degradation products has been attributed to three factors: ( 1) strength of bonds in the polymer backbone, (2) presence of tertiary hydrogens, and(3) relative strength of substituent bonds. Each of these qualitative rules is examined quantitatively using an approach combining mechanistic modeling and computational quantum chemistry. Preliminary work has already been carried out to demonstrate the application of mechanistic modeling to quantify the tendency of different polymers to degrade thermally to monomer. An education plan linking research and teaching has been formulated to teach chemical engineering students to deal with complex issues in a changing and increasingly entrepreneurial environment. The core components which comprise this plan are (1) development of generic manufacturing modules linking theoretical concepts to real world processes, (2) introduction of computational quantum chemistry into the undergraduate curriculum for property estimation, and (3) development of communication skills through individual and team oral and written presentations. Each of these is a generic component that can be incorporated throughout the curriculum.