罐付丙烯聚合反应异常原因分析及解决措施

Analysis of the abnormal reason and solution of the polymerization reaction of canister and propylene

陕西延长石油(集团)有限责任公司炼化公司两套聚丙烯装置运行约5 a后,均出现环管反应间隙性变弱、轴功率与密度不匹配等聚合反应异常问题。分别从丙烯原料中水和一氧化碳等杂质含量、装置注入的催化剂和氢气质量及丙烯储罐内防腐涂料成分等方面对问题进行了排查,最终认为丙烯储罐内涂层中含有C-O-基团、C=O基团、-OH基团物质的环氧丙烷、二氧化碳等微量杂质是造成催化剂失活、反应异常的主要原因。对丙装置分别实施打磨丙烯储罐内涂层及置换丙烯储罐措施后,并对100 kt/a聚丙烯装置进行了丙烯罐付工业试验。试验期间,装置运行平稳,未出现反应异常情况,产品收率为95.25%,较2017年直付丙烯生产期间产品收率提高了5.05%。

The two polypropylene units have all experienced some technical problems of abnormal polymerization reaction after five years of operation in Yanchang Petroleum(group) Refining and Petrochemical Company, such as weak reaction gap in the ring tube, mismatching of shaft power and density. Respectively from the content of impurities such as water and CO from propylene of the feedstock, content of catalyst and hydrogen injected into the unit, propylene tank in anticorrosion coating composition, etc. are analyzed, it is concluded that propylene tank internal coating containing C-O,C=O,-OH group reactive substances of epoxy propane, carbon dioxide and other large effect on catalyst activity trace impurities are the main causes of catalyst deactivation and abnormal reaction. After the measures of grinding the inner coating of propylene tank and replacing propylene tank, the industrial test of propylene tank delivery in 100 000 TPY polypropylene plant is carried out. The device runs stably and no abnormal reaction occur in the industrial test. Meanwhile, the yield of the product is 95.25%, which is 5.05% higher than that of the propylene production period in 2017.