Abstract:

Acetylene hydrogenation reactor is an important device for removing small amounts of acetylene in high-concentration ethylene streams in the ethylene industry. The device generally runs for a long time, during which the catalyst activity in the reactor gradually decreases until the activity cannot meet the process requirements. The full cycle operation optimization of acetylene hydrogenation reactor should be carried out rigidly according to the operation optimization scheme within the operation cycle. However, in the actual industrial process, in order to meet the temporary process scheduling requirements, the operation plan of acetylene hydrogenation reactor needs to be temporarily changed in the remaining operation cycle after running in accordance with the operation optimization plan for a certain time, which brings more changes and challenges to the operation optimization problem. Based on margin estimation and control optimization framework of slow time varying systems, the full cycle dynamic optimization problem of temporarily changing the operation optimization scheme during the operation cycle is studied in this paper. The ways to change the operation optimization scheme include: changing operation cycle and pursuing economic benefit maximization, and changing optimization objective and pursuing operation cycle maximization.Through the analysis of these two optimization schemes for changing operation, it is found that the closer the operating cycle of the former is to the original operating cycle, the higher the total economic benefit of the whole cycle. The earlier the switching time of the latter, the longer the operating cycle that the reactor can maintain. However, the full-cycle economic benefits of both are inferior to the original operation optimization plan, and temporary process scheduling is generally unfavorable to the full-cycle optimized operation of the acetylene hydrogenation reactor.

Key words: process systems engineering, operation optimization, full cycle operation optimization, acetylene hydrogenation reactor, process scheduling

摘要：

乙炔加氢反应器是乙烯工业中用于除去高浓度乙烯流中的少量乙炔的重要装置，该装置一般持续运行较长时间，期间反应器内催化剂活性逐渐降低，直至活性难以满足工艺要求。乙炔加氢反应器全周期操作优化一般是针对装置的一个再生周期进行的，在装置运行周期内应按照操作优化方案进行。但是，在实际工业过程中，为了满足临时的工艺调度需求，乙炔加氢反应器在按照操作优化方案运行一定时间后，需要在剩余的运行周期内临时改变操作方案，这给操作优化问题带来了更多变化和挑战。基于裕量估计和慢时变系统的控制优化框架，研究了这类在运行周期中临时改变操作优化方案的全周期动态优化问题。改变操作优化方案的方式包括：变更运行周期、追求经济效益最大化和变更优化目标、追求运行周期最大化。通过对这两种改变操作优化方案的分析，发现前者变更的运行周期越接近原定运行周期，全周期总经济效益越高，后者切换时刻越早，反应器能维持的运行周期越长，但二者的全周期经济效益均不及原操作优化方案，临时的工艺调度对乙炔加氢反应器的全周期优化运行总体上是不利的。

关键词: 过程系统工程, 操作优化, 全周期操作优化, 乙炔加氢反应器, 工艺调度