Career: Catalyst-Directed Resource from Waste Polymers

CTS-9623741催化剂导向资源回收是一种很有前途的技术，用于将聚合物废料转化为高价值产品，如燃料和石化产品。然而，缺乏全面的知识库限制了其应用。本研究的目的是开发一种严谨的，以科学为基础的方法，利用实验和理论从聚合物废物中回收高价值产品。实验计划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，并确定最佳的催化剂参数，以提高所提供的产品的价值。实验工作辅以理论研究，利用机制建模和计算量子化学来提供有关控制反应基础的信息。通过实验，确定了提高废聚合物有价产物回收率的有前途的策略。使用超细颗粒或均相催化剂和液体超强酸旨在通过利用聚合物的固有空隙体积来克服聚合物熔体穿透固体催化剂时遇到的固有扩散限制。然而，传统的聚合物-催化剂接触模式的优点是允许聚合物在现有的处理单元中进行处理。因此，研究了多相催化剂的相关设计参数，即酸度/碱度和结构。实验工作由理论研究补充，旨在对给定聚合物原料和催化剂配方的降解特性进行先验预测。从实验研究中积累的数据库提供了一般的定性规则，作为制定预测性定量机制模型的起点。一般来说，聚合物对特定降解产物的倾向可归因于三个因素：(1)聚合物主链中键的强度，(2)叔氢的存在，(3)取代键的相对强度。这些定性规则中的每一个都使用结合机制建模和计算量子化学的方法进行定量检查。初步的工作已经开展，以证明机械建模的应用，以量化不同聚合物的热降解为单体的趋势。制定了一项将研究与教学联系起来的教育计划，以教导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。组成该计划的核心组成部分是(1)将理论概念与现实世界过程联系起来的通用制造模块的开发，(2)将计算量子化学引入本科课程以进行属性估计，以及(3)通过个人和团队口头和书面陈述发展沟通技巧。这些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.