微反应器CO2捕集过程中的气泡传质机理以及气-液微反应器的集成与放大

CO2 capture is an effective way to control emissions of greenhouse gas, the absorption of CO2 by microreactor is a promising method to achieve efficient emission reduction. The formation and movement behavior, the velocity field, concentration field in liquid phase and their evolution would be real-time observed and recorded by a high speed digital camera, a high frequency micro-particle image velocimetry and a micro laser induced fluorescence detector. The lattice-Boltzmann (LBM) method and volume of fluid (VOF) method would be used to simulate the formation, movement and breakup of bubble and mass transfer between gas and liquid phases in a complex multiple-channel microreactor. The influences of the reactor structure, absorbent property and operation conditions on the formation, movement and breakup of bubble and mass transfer between gas-liquid two phases would be investigated systematically, and the controlling factors for pressure drop and mass transfer efficiency would also be explored. The mechanisms of the formation and breakup of bubble, the evolution regulation and coupling mechanism of bubble interface and liquid velocity and concentration fields would be proposed for the CO2 capture process in microreactor. Furthermore, the non-linear interface mass transfer model would be established by considering micro scale effect. Finally, the integration and optimization method of microreactor would be proposed for the design and industrial application.

CO2捕集是控制温室气体排放的有效途径，微反应器溶剂法吸收CO2是实现其高效减排的前沿方法。本项目拟采用高速摄像仪、高频显微粒子图像测速仪（μ-PIV）以及激光诱导荧光测定仪（μ-LIF）实时观测和研究微反应器内CO2捕集过程中气泡的分散与流动特性以及液相流场与浓度场的变化规律。采用格子-玻尔兹曼（LIB）法和流体体积（VOF）法对复杂多通道微反应器内气泡的分散、流动与传质过程进行数值模拟。考察微反应器结构、溶剂性质和操作条件对气泡生成、运动、破裂及传质的影响。提出微反应器CO2捕集过程气泡的生成及破裂机理，揭示气液界面、液相速度场及浓度场的演化规律与耦合机制，探索压力降与传质效率的控制因素，建立微尺度条件下气泡传质的非线性耦合模型。提出微反应器的集成和优化方法，为微反应器CO2捕集的设计和工业应用提供理论基础。

为了减少碳排放，缓解温室效应，CO2的高效捕集是非常重要的。本项目系统研究了微通道内CO2的吸收及传质特性，考察了微通道构型、吸收剂类型、吸收剂浓度、气相流量及液相流量对CO2的吸收效率、气泡行为、传质系数的影响。揭示了气泡生成机理与破裂机理，建立了微通道内气液传质模型。针对构型微通道，分析了气液吸收过程的能耗与传质系数间的耦合关系，揭示了构型微通道对传质的强化机理，以及气液流型与传质的耦合机理。设计了不同构型的并行多通道微反应器，研究了微反应器的放大对气液分配、压降、传质特性的影响，分别建立了微反应器内化学吸收过程的压降模型和气液传质模型，提出了微反应器的放大准则和集成优化方法。研究成果可为CO2捕集微反应器的设计及应用提供重要的理论基础和技术指导。