“复杂化工过程物质转化机理与能效分析”立项报告

Energy Efficiency and Mass Transformation Mechanism of Complicated Chemical Processes:Application Report

我国化学工业整体水平距离世界先进水平仍有较大差距,缺乏核心竞争力;同时面临着节能、减排和降耗等迫切要求。随着介观和微观物理化学现象测量与表征技术的进步,以及计算机和计算方法的飞速发展,开始具备条件认识和描述物质转化过程中涉及的复杂物理化学过程。近年来化学工程的研究工作已从宏观现象描述和实验数据关联逐步转向对物质转化过程的本质的认识。该项目将以乙烯工业中的主要生产单元为主要研究对象,研究主要反应的反应机理和动力学;流场结构形成机制与调控和反应/传递过程协同机制及能效分析。通过研究分析过程与设备行为特征,确定和优化对过程能效有决定性影响的特征结构。形成基于微观反应动力学建立宏观反应动力学模型的方法、利用反应-扩散模拟预测颗粒动力学的方法以及反应动力学与流场结构有机结合的过程模型化方法,建立物质转化机理与过程效率的联系,用以实现过程行为的预测和优化。提出基于反应器内构件结构优化的流体流动和相间接触结构化及过程强化方法,包括特定结构内构件的构建、内构件及其组合与操作方式的匹配、特定内构件与其相应的操作参数协调等,以对反应器的多尺度流场结构进行多方面、多层次协同控制,到达反应/传递协同增效的目标。形成通过塔间或塔内透热的乙烯精馏分离系统能量集成关键技术,从根本上提高精馏过程热力学效率,实现乙烯分离流程的单元设备节能10%以上。

The state of art of chemical industries as a whole in our country is far behind the advanced level in the world, as testified by the lack of the core competitiveness. The techniques for energies saving, wastes reduction and consumption loweringare highly desired. With the development of the measurement and characterization techniques and the advance of computerhardware and software, the researchers now have the capability of cognition and description of the complicated chemicalprocess. The researches in chemical engineering field have been transferred from correlation of macroscopic phenomena todescription of the intrinsic mass transformation mechanism. Targeted to the important process units in ethylene industry, thereaction mechanisms and kinetics of some main reactions, the formation mechanism and its adjustment of the fluid field andthe synergic effects and energy efficiencies of the coupled reaction/transportation process are to be studies in this project toanalyze the characteristics of process and equipment behaviors and determine the key structure properties for the process energyefficiencies. The methods of modeling macro-kinetics based on microkinetic analysis, prediction of apparent kinetics on catalystparticles by multi-scale reaction-diffusion modeling and process simulation by combined kinetics and computational fluiddynamics are to be developed, by which the relationship between mass transformation mechanism and energy efficiencies isto be built for prediction and optimization the process performances. A practical way based on novel inserts designs and theirmatching with operation conditions is brought out to achieve the synergic manipulation of multi-scale fluid field to improvethe process energy efficiencies. The novel ethylene purification process by adopting intermediate heat-integrated sequence ofdistillation columns is proposed. This process would fundamentally improve the energy efficiencies of distillation columns andsave energy consumption of ethylene purification process above 10%.