气固催化羟醛缩合反应耦合膜分离体系的构筑及过程基础研究

The process of acrylic acid/methyl acrylate synthesis via one-step aldol condensation reaction of formaldehyde and acetic acid/methyl acetate is an important way to utilize coal-based chemicals with high value. In view of the current problem of low yield and difficulty in the separation of water generated, the study proposes a new process of coupling catalytic reaction and membrane separation, mainly based on core scientific issues such as the synthesis of acid-base bifunctional catalysts, the development of new Selective permeation membrane materials for water separation, and the study of process intensification theory. The structure-activity relationships of the catalyst and the inorganic water-dividing membrane material will be studied by means of material preparation, theoretical calculation, structural characterization and performance evaluation. The catalyst with high conversion and high selectivity and the inorganic membrane material with high water flux and low transmission resistance will be developed. The molecular behavior of microscopic layer on the crystal surface process including adsorption, reaction, and transfer will be studied. The catalysis-separation integrated membrane materials will be designed, and the gas-solid catalysis-membrane separation coupling device will be constructed. The process matching and synergistic control were investigated, and the membrane reactor and operating conditions will be optimized. According to in-situ spectroscopy and molecular simulation methods, the adsorption-reaction-transport process of microscopic molecules on the crystal surface will be explored. The reaction kinetics and osmotic diffusion kinetics will be systematically investigated, and the gas-solid catalytic reaction-membrane separation coupling device was constructed. Through the matching of process conditions, the coordinated control of the aldol condensation catalytic process and the membrane separation process will be achieved, and finally the continuous operation of the coupling process will be realized.

甲醛和醋酸/醋酸甲酯经一步羟醛缩合反应合成丙烯酸/丙烯酸甲酯是煤基化学品高值化利用的重要途径。本项目针对该反应过程收率低且生成水难分离这一难点问题为切入点，针对催化剂和膜分离耦合过程的可行性，基于酸碱双功能催化剂合成、新型水渗透选择性膜材料开发和过程强化理论研究的关键科学问题，提出了催化反应-膜分离耦合的新过程。重点研究高分散酸碱微通道催化剂和耐高温分水膜的构效关系，设计合成催化-分离一体化膜材料，建立气固催化-膜分离耦合装置，研究过程匹配和协同控制规律，优化耦合膜反应器设计及操作条件，运用原位光谱和分子模拟等手段，探究微观层面分子在晶体表面的吸附-反应-传递过程，掌握制备透水性能优良、催化活性高、稳定性好的膜催化剂的关键技术，获得反应-渗透扩散动力学模型，为气固羟醛缩合反应的催化-分离原位耦合过程设计提供科学依据。

利用气固相催化反应实现分子偶联制备高附加值化学品是煤化工领域重要研究方向，比如羟醛缩合反应制备丙烯酸/甲基丙烯酸、氧化酯化反应制备甲基丙烯酸甲酯、氢转移反应制备甲基烯丙醇等反应过程，该类反应过程存在收率低且生成水难分离的问题，因此开发高收率的催化剂和实现水的及时分离是实现羟醛缩合反应高效稳定进行的关键。本项目采用球磨法或浸渍法制备了一系列高分散γ-Al2O3负载型酸碱双功能催化剂，系统研究了载体与活性组分催化羟醛缩合反应的构效关系，优化了反应工艺条件，实现了反应的高转化率（51.51%）和选择率（~100%），揭示了酸碱双功能催化剂对羟醛缩合反应的催化作用机制；采用二次提拉法合成了一系列离子化修饰MOR分子筛复合膜材料，考察了膜的制备条件对膜材料渗透汽化性能的影响规律，揭示了膜表面设计和膜分离性能的构效关系，实现水的高效分离；基于催化剂和膜分离耦合过程的可行性，构建了催化-分离原位耦合过程，研究了反应动力学模型和传递分离模型，获得全流程的反应-传递理论模型，并将该理论模型成功应用到甲基丙烯醛氧化酯化耦合磁分离生产甲基丙烯酸甲酯的反应过程中，实现了催化耦合分离过程的强化和反应的连续化，为催化-分离原位耦合化工过程强化提供重要的理论基础和实践指导。