Oxidation of Polychlorinated Biphenyls (PCBs) in Supercritical Water

摘要/ abstract摘要：Lawrence L. Tavlarides机构：Syracuse university提案号：0115650该项目的目标是通过发展基础知识来推进超临界水氧化（SCWO）工艺的现有技术，该技术可用于定义一种高效且环保的方法来破坏从受污染的土壤/沉积物或处置场地提取的有毒多氯联苯（pcb）。多氯联苯是一种剧毒的有机污染物（POPs），最近被122个国家列入了一份被称为“十二种污染物质”的禁用清单。209个PCB同系物大约是元素周期表中元素数量的两倍，氯苯数量的17倍，为研究提供了类似象棋的可能性。系统地选择同系物和最常用的工业PCB混合物将在纯水和甲醇溶液中氧化。重点将放在甲醇溶液上，因为观察到MeOH对PCB脱氯的速率提高。还将研究从PCB污染的现实世界沉积物中提取SC-CO2/MeOH的几种解决方案，以将PI正在开发的土壤修复技术的提取和氧化步骤结合起来。这种方法将允许人们在不进行动力学研究和不使用反应速率增强剂的情况下，在较不严重的条件下，设计和优化运行具有竞争力的多氯联苯和其他相关污染物的SCWO大型装置。基于实验结果，反应动力学和途径以及结构-反应性关系将得到发展。PCB在超临界水中的氧化实验将在高压等温塞流管式反应器中进行，该反应器能够在温度高达873 K，压力高达60 MPa的情况下连续运行。方法是选择热力学、动力学和工艺参数，以找到最佳条件，以实现在最小侵略性条件下安全高效地破坏PCB的战略目标。考虑的主要参数是温度（673 - 874 K）、压力（25 - 35 MPa）、停留时间（1-240 s）和溶质浓度（MeOH为0.1 - 10 g/L， SCW为10-3 - 10 mmol/L）。这些知识将通过出版物和演讲传播给研究界，并将向学生，包括生活在多氯联苯污染土地上的美洲原住民提供示范培训/教育。

ABSTRACTPI: Lawrence L. Tavlarides Institution: Syracuse UniversityProposal Number: 0115650The goal of this project is to advance the existing technology of the supercritical water oxidation (SCWO) process by developing fundamental knowledge which can be used to define an efficient and environmentally safe way to destroy toxic polychlorinated biphenyls (PCBs) extracted from contaminated soil/sediments or from disposal sites. PCBs are highly toxic organic pollutants (POPs) included by 122 nations on a recently banned list of chemicals known as the "dirty dozen." The 209 PCB congeners are approximately twice the number of the elements in the Periodic Table and 17 times the number of chlorobenzenes, offering chess0like possibilities of investigations. Systematically selected congeners and the most used industrial PCB mixtures will be oxidized in SCW both neat and methanolic solutions. Emphasis will be on the methanolic solutions due to observed rate-enhancing quality of MeOH on PCB dechlorination. Several solutions obtained by SC-CO2/MeOH extraction from PCB polluted real world sediments will also be studied to couple the extraction and oxidation steps of a soil remediation technology being developed by the PI. This approach will permit one to design and optimally operate competitive SCWO large-scale units for PCBs and other related pollutants under less severe conditions than those proposed without kinetic studies and without reaction rate enhancers. Based on experimental results, reaction kinetics and pathways and structure-reactivity relationships will be developed.PCB oxidation experiments in supercritical water will be conducted in a high-pressure, isothermal plug-flow tubular reactor capable of continuous operation at temperatures up to 873 K and pressures up to 60 MPa. The approach is to select thermodynamic, kinetic and process parameters in order to find the optimum conditions for achieving the strategic goal of safe and efficient PCB destruction under the least aggressive conditions. The main parameters considered are temperature (673 - 874 K), pressure (25 - 35 MPa), residence time (1-240 s), and solute concentration (0.1 - 10 g/L in MeOH, and 10-3 - 10 mmol/L in SCW). This knowledge will be disseminated to the research community through publications and presentations and will provide a model training/education to students, including Native Americans living on PCB contaminated lands.