关键词: 苯乙烯, 产品储罐, 聚合物含量超标, 储存温度, 阻聚剂, 储存时间, 预防性清罐, 循环水温度

Abstract:

In 2020 and 2021, a styrene unit of a certain refining and chemical company encountered problems with polymer content of product storage tanks exceeding the standard and substandard products, which had a significant impact on the normal production of the unit and the delivery of products. After tank cleaning inspection, no obvious factors that could easily lead to polymerization reactions were found in tank bottom, tank wall and external safety accessories. After multiple discussions, analysis, and investigation, it was found that excessive polymer content in styrene products is related to the storage temperature, storage capacity, and residence time of styrene products in the storage tank, which is the result of the combined effect of these factors. According to the preliminary analysis results, the corresponding process parameters were adjusted during production in the summer of 2022: reducing the storage capacity of product storage tanks during high-temperature periods, reducing the residence time of products in storage tanks, and conducting preventive tank cleaning treatment on the storage tanks. The problem did not occur again throughout the summer.

Key words: styrene, product storage tank, excessive polymer content, storage temperature, polymer inhibitor, storage time, preventive tank cleaning, circulating water temperature