Multiscale Process Intensification of Waste Valorization Reactions

我的研究计划的中心主题是开发强化和可持续的化学过程，用于回收金属，封存二氧化碳，并利用工业，城市和农业废物生产有价值的无机材料。处理固体废物-流体反应时的一个挑战是，固-液、固-气和气-液界面上的传质限制和不利的热力学导致反应速率缓慢、反应转化不完全、能量消耗和加工成本高以及产品性能不足。克服淤浆反应局限性的传统方法是调整工艺变量，如温度、压力、粒度、混合速率和试剂浓度。这些宏观规模的方法可能是有效的，但是，它们对环境造成了代价：能源和原材料的高消耗，大量残留物的产生，以及污染物和温室气体的排放。在低品位和废物资源的处理或增值中，这种常规方法在工业规模上通常是不可行的。因此，需要可持续的解决方案。*该DG计划的目的是通过探索和开发作用于不同空间和时间尺度的过程强化策略，克服与环境相关的浆料反应的反应速率限制。长期目标是稳定三类固体废物的价格：（a）金伯利岩和蛇纹石（矿物加工）;（B）黑/红液体（纸浆和纸）;（c）水果/蔬菜渣（水果加工）。短期研究集中在三个领域：（1）反应和反应器设计;（2）反应分离;和（3）溶剂机械化学。针对这些领域，研究了五种多尺度强化方法：*（i）将机械搅拌间歇反应转化为超声活塞流连续反应;*（ii）开发用于特定废物转化反应的新型催化矿物;*（iii）用超疏水分子使惰性固体介质功能化;*（iv）使用不混溶有机相和金属有机框架（MOF）化合物进行反应萃取;*（iv）使用超疏水分子使惰性固体介质功能化。和 *（v）用绿色溶剂代替水性反应介质，用于反应性吸收和溶剂机械化学。**最终，这项研究计划的目的是鼓励采用过程强化技术代替传统工艺，在工业和研究界，并促进化学，冶金和矿产工业（加拿大的经济驱动力）所需的可持续工艺类型的发展，以减少其对环境的影响和碳排放。此外，所开发的多尺度过程强化方法还可以扩展到其他工业、城市和农业过程，在这些过程中，可以实现能源强度、碳强度和环境足迹的降低。

The central theme of my research program is the development of intensified and sustainable chemical processes for the recovery of metals, the sequestration of CO2, and the production of valuable inorganic materials, using wastes of industrial, urban and agricultural origins. A challenge when working with solid waste-fluid reactions is that mass transfer limitations across solid-liquid, solid-gas and gas-liquid interfaces and unfavorable thermodynamics lead to slow reaction rates, incomplete reaction conversions, high energy expenditure and processing costs, and inadequate product properties.******The traditional approach to overcoming slurry reaction limitations is to adjust process variables, such as temperature, pressure, particle size, mixing rate, and concentration of reagents. These macro-scale approaches can be effective, however, they come at a cost to the environment: high consumption of energy and raw materials, vast generation of residues, and emissions of pollutants and greenhouse gases. In the treatment or valorization of low-grade and waste resources, such conventional approaches are often unfeasible at the industrial scale. Sustainable solutions are thus needed.******The aim of this DG program is to overcome reaction rate limitations of slurry reactions of environmental relevance, by exploring and developing process intensification strategies that act over different scales of space and time. The long-term objective is to valorize three classes of solid wastes: (a) kimberlite and serpentine (mineral processing); (b) black/red liquors (pulp and paper); (c) fruit/vegetable pomace (fruit processing). The short-term research is clustered in three areas: (1) reaction and reactor design; (2) reactive separations; and (3) solvomechanochemistry. For these areas, five multiscale intensification approaches are investigated:***(i) converting mechanically stirred batch reactions into sonicated plug flow continuous reactions;***(ii) developing novel catalytic minerals for specific waste conversion reactions;***(iii) functionalizing inert solid media with superhydrophobic molecules;***(iv) using immiscible organic phases and metal-organic framework (MOF) compounds for reactive extraction; and***(v) replacing aqueous reaction media with green solvents for reactive absorption and solvomechanochemistry.******Ultimately, the purpose of this research program is to encourage the adoption of process intensification technologies in place of conventional processes, in industry and among the research community, and to catalyze the development of the types of sustainable processes required by the chemical, metallurgical and minerals industries (Canada's economic drivers) to reduce their environmental impact and carbon emissions. Moreover, the multiscale process intensification approaches developed may also be extended to other industrial, urban and agricultural processes where reduction of energy intensity, carbon intensity and environmental footprint could be achieved.**