醋酸乙烯聚合反应系统热失控与安全泄放

摘要

醋酸乙烯聚合过程操作不当会发生热失控，导致暴聚，安全泄放能力是防止聚合反应釜发生超压事故的关键。为此，利用VSP2绝热量热仪，针对冷却失效、引发剂量大、甲醇溶剂进料量低等主要危险情景开展醋酸乙烯聚合失控实验研究，计算反应釜安全泄放面积。通过对比不同温升速率、压升速率、反应温度下的TMRad等失控反应特征数据发现，引发剂量过大的工况为最危险情景；在65℃时，反应压力曲线基本闭合，确定反应体系为温和型蒸气系统。采用Leung法和平衡速率模型进行了安全泄放量、泄放能力计算，并利用校正系数Kc、流量系数Kd进行安全泄放面积校正，获得了反应釜的最小安全泄放面积。%Thermal runaway may happen in vinyl acetate polymerization reactors under conditions of excessive initiator and cooling failure, which leads to violent polymerization. Experiments were designed to study thermal runaway and safety relief in typical hazardous scenarios using a bench-scale adiabatic calorimeter VSP2. The results show that excessive initiator is determined as the main factor when comparing peak temperature rising rate, peak pressure rising rate and TMRad under process temperatures. The polymerization reactor is classified as a mild steam system with closed pressure curves. Safe relief rate, flow capacity and the minimum vent area are calculated based on the Leung’s method and ERM model. The calculation results are corrected by correction factor Kc and flow coefficient Kd following real process conditions and the safety vent area is acquired.