微反应器用于柴油萃取-催化氧化超深度脱硫过程调控及强化机理研究

Serious environmental problems and strict environmental laws make ultra-deep desulfurization of diesel become an urgent subject worldwide. Among the ultra-deep desulfurization methods, extractive and catalytic oxidative desulfurization (ECODS) process is considered as one of the most perspective non-hydrodesulfurization technologies. Nevertheless, continuous stirred tank reactor that widely used in the ECODS process is difficult to achieve efficient transfer without backmixing, which limits its further development. Microreactor, by contrast, is featured good transfer performance and thereby provides new opportunities for the EODS process. However, it involves complicated coupling mechanism between transfer and reaction, which needs to be studied thoroughly. Therefore, in this project, an ECODS system, composed of diesel-ionic liquid-hydrogen peroxide, is chosen for the research subject to investigate principles of multiphase-fluid flow, mass transfer and reaction. As a result, flow patterns and mass transfer performance of liquid-liquid-liquid three-phase in microreactor will be acquired and coupling principles between transfer and reaction in the ECODS process will be revealed. In addition, control and intensification methodology of the ECODS process from system hierarchy to micro-level will be formed. Based on above researches, micro reaction system of the ECODS process will be established and the key chemical reaction engineering issues of the process will be illustrated, which will provide the theoretical basis for development of novel technology about diesel ultra-deep desulfurization technology based on the microchemical technology.

日益严峻的环境问题和日趋严格的环保法规使柴油超深度脱硫迫在眉睫。萃取-氧化脱硫工艺是最有前景的柴油非加氢超深度脱硫工艺之一，鉴于传统连续搅拌釜式反应器难以同时实现高效传递和抑制返混，具有良好传递性能的微反应器为该工艺提供了新契机，但其蕴含的复杂多相传递与反应耦合机理有待深入研究。鉴于此，本项目以柴油-离子液体-双氧水为研究对象，对萃取-催化氧化超深度脱硫过程涉及的多相流体流动、传质与反应耦合规律进行研究，力求认识微反应器内液-液-液三相流动形态和传质特性，揭示该过程的传递与反应耦合机理，形成从系统层次调控和微观层次强化脱硫过程的方法，实现有效调控和过程强化，构建柴油超深度脱硫的微反应体系，阐明相关的化学反应工程关键科学问题，为开发基于微化工技术的柴油超深度脱硫新技术提供理论基础。

日益严峻的环境问题和日趋严格的环保法规使柴油超深度脱硫迫在眉睫。萃取-氧化脱硫耦合工艺（ECODS）是最有前景的柴油非加氢超深度脱硫工艺之一。鉴于传统连续搅拌釜式反应器难以同时实现高效传递和抑制返混，具有良好传递性能的微反应器为该工艺提供了新契机，但其蕴含的复杂多相传递与反应耦合机理有待深入研究。本项目以柴油-离子液体-双氧水为研究对象，对ECODS过程涉及的多相流体流动、传质与反应特性进行了研究，旨在实现对ECODS工艺的有效调控和过程强化。. 选取不同类型的两种离子液体，考察了柴油-离子液体-双氧水两相或三相体系在微通道内流动状况，并建立了分散相尺寸与操作参数的预测关联式，明确了两相体系内液滴的融合机制。研究了微通道内柴油的ECODS行为，延长停留时间、增大离子液体和双氧水用量、提高反应温度一定程度上可提高脱硫率，但需选择合适的工艺条件兼顾脱硫率和经济性。耦合萃取过程的传质速率方程和氧化过程的反应动力学模型，建立了ECODS动力学模型，发现DBT氧化反应是个极易进行的快反应，使得传质成为脱硫过程的速率控制步骤，且传质阻力主要集中于离子液体侧；温度升高、相界面积增大均可减小传质阻力，进而实现ECODS过程的强化。这些研究结果为开发基于微化工技术的柴油超深度脱硫新技术提供了理论基础。