耦合中温气化与高温化学链的修复植物热处理新方法过程中重金属的定向迁移与协同脱除机理研究

随着植物修复技术在土壤重金属污染治理领域的大面积应用，发展配套的修复植物产后无害化与资源化利用技术具有重要实际意义。本项目拟研发一种基于化学链气化理念的修复植物两段式热处理新方法系统。该方法将中温气化与高温化学链相耦合：中温气化炉内实现修复植物的一级气化获得粗制可燃气，重点确保大部分重金属向底渣迁移和富集；化学链还原反应器内利用载氧体的晶格氧实现粗制可燃气的二次气化重整，重点实现载氧体对重金属的固化吸附；化学链氧化反应器中实现失氧载氧体的氧化再生。本项目旨在通过理论设计、试验研究以及数值模拟相结合的方式，探索新方法气氛下修复植物重金属的定向迁移转化机制，同时掌握载氧体和重金属间的相互作用机理，结合先进制备工艺，赋予载氧体重金属吸附能力，从而协同底渣富集完成对修复植物重金属的有效捕集。本项目的成功实施有望为无害化以及资源化利用产后修复植物提供一种新的解决方案，具有重要的理论和实际应用价值。

With the large-scale application of phytoremediation technology in the field of soil heavy metal pollution control, it is of great practical significance to develop related technologies for harmless and resource utilization of after-use phytoremediation plants. This project plans to develop a novel two-stage thermal disposal system of phytoremediation plant based on the concept of chemical looping gasification. The method couples the medium-temperature gasification and the high-temperature chemical looping processes. In detail, the first-stage gasification of phytoremediation plant in the medium-temperature gasification furnace generates the rough combustible gases, and meanwhile ensures most of the heavy metals be migrated and enriched to the residue. Then, the secondary gasification reforming of the rough combustible gases off the medium-temperature gasification furnace is further realized with the use of the lattice oxygen from the oxygen carrier in the chemical-looping reduction reactor, in which heavy metals are also cured and absorbed by the oxygen carrier. Finally, the oxygen-deprived oxygen carrier is regenerated in the chemical-looping oxidation reactor. With the method of combining theoretical design, experimental research and numerical simulation, this project aims to explore the mechanism of directional migration and transformation of heavy metals under the atmosphere of this novel disposal method of phytoremediation plant, and meanwhile to master the interaction mechanism between oxygen carriers and heavy metals. In this context, with the help of advanced preparation techniques, the oxygen carrier is expected to own the adsorption capacity of heavy metals. Thus, the effective capture of phytoremediation plant heavy metals can be achieved with the combination of the adsorption by the residue and the modified oxygen carrier. The implementation of this project is expected to provide a new solution for the harmless and resourceful utilization of after-use phytoremediation plants, which will have important theoretical value and practical significance.