生物酶催化反应精馏新技术基础研究

The biological enzyme catalyst has the advantages of mild reaction condition, strong specificity, high efficiency, and could be used in reaction distillation to avoid pollution problems such as strong acid or alkali catalyst, it is the research direction of a characteristic advantage in the process intensification of separation. In this project, using transesterification as model reaction, the biologic enzyme catalyst was coated on the surface of the filler to replace the traditional acid base catalyst for the reaction distillation process, probe into the feasibility of enzymatic reaction distillation process; In order to solve the problems of enzyme carrier filler preparation and aging shortness and inefficiency of enzyme immobilization, study on preparation and modification of enzyme carrier and its effect on enzyme activity and stability from microcosmic point of view; Study on the change of the structure of enzyme - carrying filler with the preparation conditions and modification methods, reveal the synthesis and regulation mechanism of the microstructures of enzyme carrier fillers, further explanation of the structure-activity relationship of enzyme carriers; Establishment kinetic model of enzymatic reaction distillation, study on the fluid flow behavior on the surface of enzymatic packing, probe into enzymatic reaction distillation process enhancement mechanism, Regulating and solving the difficulties of enzymatic reaction distillation process such as immobilized enzyme technology, to realize the stability and long - term performance of the catalytic reaction rectification of the biological enzyme. Through the implementation of this project, providing scientific support and theoretical basis for its further industrialization.

生物酶催化具有反应条件温和、专一性强、效率高等优势，可用于反应精馏中以避免强酸或强碱催化剂等污染问题，是分离过程强化中一个特色优势的研究方向。本项目拟以酯交换为模型反应，将生物酶催化剂涂覆固定在填料表面替代传统酸碱催化剂用于反应精馏过程，探究酶促反应精馏过程的可行性；针对载酶填料制备及酶固载时效短、效率低等问题，从微观角度研究载酶填料的制备和修饰及对酶活性和稳定性的影响；探索载酶填料结构随制备条件及修饰方法的变化规律，揭示载酶填料微结构的合成与调控机制，阐明载酶填料的构效关系；建立酶催化反应精馏动力学模型，研究载酶填料表面流体流动行为；探究酶促反应精馏过程强化机理，调控和解决酶促反应精馏技术实施过程中的固载酶技术等难点，实现酶催化反应精馏的稳定性和长效性。同时通过丁酯合成反应精馏这一过程案例进行验证，为工业化实施提供理论支撑和技术基础。

反应精馏是化工过程强化中最具特色的单元操作之一，其分离过程可促进产品收率的提高、同时反应热又促进产品的分离。但是，该过程中多用到强酸、强碱类催化剂，且不能从根本上解决酸碱的环境污染问题。. 生物酶催化剂具有反应条件温和、专一性强、效率高易于过程强化和优化等优势。故生物酶催化与反应精馏的集成将是化工分离过程的重大革新。.本研究以生物酶催化制备丁酯为模型反应，重点考察了（1）载酶填料的在塑料和钢制填料上的制备、修饰和调控过程，得到了性能优良的载酶填料。揭示了制备条件及修饰方法的变化规律与构效关系；得到较优的喷涂操作条件为：喷涂流量1.82kg/h，喷涂压力1bar，喷涂距离15cm。固定化酶后酶活性为490U/g，相对游离酶的活性为97.3%，蛋白固定化率为96%，载酶填料在设备内运行半年后，其催化性能仍可以保持在75-80%，提升了生物酶催化剂的稳定性和催化性能的高效性。（2）酶促反应精馏过程强化与优化。通过调控并优化固定化酶过程，揭示了生物酶催化对反应精馏过程强化机制及规律，得到了酶催化反应精馏的较优操作条件，凸显了生物酶催化的绿色和反应精馏的集成。小试实验结果为：反应段板数11块，精馏段板数7块，提馏段板数8块，操作回流比为6，乙酸乙酯与正丁醇的摩尔比为3:1。（3）以生物酶催化合成乙酸正丁酯为模型反应，建立了二级拟均相动力学模型，利用最小二乘法拟合动力学数据，确定了动力学方程。在反应机理与实验数据的基础上进行流程模拟，利用流程模拟软件Aspen Plus建立了生物酶催化酯交换反应精馏的数学模型，模型计算与实验相符，证实了模型的准确性。结合统计学方法RSM相结合对酶促反应精馏过程的数学模型进行了优化，最终乙酸正丁酯质量浓度为86.7%。. 本研究在凸显二者各自优势的前提下，实现了生物酶绿色催化与反应精馏的高效集成。