催化精馏塔催化填料内催化反应对汽液传质过程影响机制研究

Chemical process intensification is an important technology which can be used to solve the contradiction between pollution and development from the source. Catalytic distillation, which integrates the catalytic reaction and distillation in a single multifunction process unit, is a well-known example of process intensification. The packing method of catalyst pellets is the core technology of catalytic distillation process. However, the determination of catalytic packing structure parameters was mostly relied on engineering experience at present. The fundamental way to solve this key problem is to make the relationship between structure and performance of catalyst packing clear. In the earlier study, the applicant used a two-way coupling multi-scale model to clarify the relationship between structure parameter of catalyst layer and macroscopic reaction performance. However, the influence of macroscopic reaction rate on vapor-liquid mass transfer process was not considered. In the present study, the CFD numerical simulation will be used to establish a microscopic model which considers the influence of catalytic reaction on gas and liquid mass transfer coefficients. By combining the proposed model and non-equilibrium model, a multi-scale model will be established. By the utilization of the proposed multi-scale model, the influence of catalytic reaction rate on vapor-liquid mass transfer process will be investigated deeply. The relationship between structure parameter of vapor-liquid mass transfer unit and the efficiency of catalytic distillation will be elucidated. The process-specific catalytic packing structure will be developed. The established multi-scale model will provide a theoretical guide and practical support for the achievement of high-efficiently catalytic distillation process.

化工过程强化技术是从源头上解决化学工业“污染-发展”矛盾的重要手段。催化精馏是将催化反应与精馏过程耦合在同一设备中同时进行的一种重要的化工过程强化技术，其关键核心技术在于催化剂的装填方式。目前工业上对催化填料结构的确定大多还依赖于工程经验，因此弄清催化填料结构与性能之间的构效关系是解决催化精馏塔关键核心问题的根本途径。申请者在前期研究过程中，已利用双向耦合的多尺度数学模型阐明了催化层结构与宏观反应性能之间的构效关系，但忽略了催化反应速率变化对汽液传质过程的影响。因此，本课题拟将采用CFD数值模拟方法建立考虑催化反应影响的气膜、液膜传质系数微观模型，并结合宏观非平衡级数学模型建立一种多尺度的数学模型，深入分析催化反应速率对汽液传质过程的影响，弄清汽液传质层结构参数与催化精馏效率之间的构效关系，设计开发出具有针对性的催化填料结构，为实现高效催化精馏过程提供理论指导和实际支撑。

催化精馏是将催化反应与精馏过程耦合在同一设备中同时进行的一种重要的化工过程强化技术，其关键核心技术在于催化剂的装填方式。目前工业上对催化填料结构的确定大多还依赖于工程经验，因此弄清催化填料结构与性能之间的构效关系是解决催化精馏塔关键核心问题的根本途径。催化填料可以看作是由催化剂层和汽液传质层按一定结构组合而成。本项目首先在催化剂层尺度上，构建能够描述催化剂层内反应与传质过程的CFD数学模型，研究考察催化剂层结构参数对催化剂层效率因子的影响，建立包含结构参数影响的催化剂层效率因子关联表达式。其次，在汽液传质层尺度上，采用示踪剂方法研究汽液传质层内的气、液传质行为，构建包含有结构参数的影响气、液膜传质系数关联表达式。最后，利用建立的催化剂层效率因子关联表达式以及气、液膜传质系数关联表达式结合传统非平衡级过程模拟，构建催化剂层/汽液传质层-催化填料-催化精馏塔多尺度数学模型，研究考察催化剂层、汽液传质层结构参数对催化精馏效率的影响，揭示其构效关系，设计开发与催化精馏工艺高度匹配的催化填料结构，为实现高效催化精馏过程提供理论指导和实际支撑。另外，本项目还扩展至催化剂层内多相流动和多组分反应与传质特性、催化剂颗粒内反应与传质特性以及负载型催化填料制备等研究。目前已发表SCI/EI收录论文8篇，授权专利5项。