醋酸裂解后续过程的能量回收

Energy recovery in process of acetic acid cracking

醋酸裂解是化工生产中的一个重要过程,其后续过程中存在着能量未充分回收利用的情况。文中利用夹点技术对醋酸裂解后续工艺的用能情况进行分析,经分析该系统为阀值问题,系统中热量过剩,故不需外加热源,所有冷物流升温所需的热量均由热工艺物流提供。但由于公用工程的引入,系统出现了2个公用工程夹点,仍需遵循夹点分析原则进行设计。针对现有的工艺流程的用能情况,利用夹点分析软件Aspen Energy Analyzer,依据夹点匹配的要求,同时考虑阀值问题的换热网络设计原则,文中提出了2种节能改造方案,并对2个方案的节能效果进行比较。经计算2个方案的节能效果均可达到40%以上,综合各方面因素考虑,方案1改造效果更好,应优先考虑。通过对醋酸裂解过程换热网络的改造,可减少冷热公用工程用量,节约成本,提高经济效益。

Acetic acid cracking is an important process in the chemical industry production, and there exists the underutilized energy recycling in its follow-up process. The energy consumption of the follow-up process of acetic acid cracking was analyzed through the pinch technology. It shows that the heat exchanger network is a threshold problem. With the excess heat in the system, no additional heating resource is needed and all energy needed for the temperature rise of cold flows is provided by the hot flows. Two utilities pinch points exist in this system due to the use of utilities, and the rules of pinch analysis still apply to the design. Considering the energy consumption of present process, according to the existing pinch matching requirements and the design principles of heat exchanger network in which the threshold issue is considered and based on the pinch analysis software （Aspen Energy Analyzer）, two programs of energy saving were proposed and compared. More than 40% energy can be saved by both the programs, and the Project 1 is better when considering all factors. So it can reduce the utilities usage, cut cost and improve economic benefits by reforming the heat exchanger network of acetic acid cracking process.