中文摘要：

为定量评估芳烃装置歧化单元安全和环境风险,采用机制模型与传统危险与可操作性分析（HAZOP）相结合的方法,对该装置的循环氢压缩机失效等3个典型事故进行定量危害分析;针对3起事故中发生的苯泄漏情形,进一步采用工艺危害分析软件（PHAST）和危险环境区域（ALOHA）软件,模拟苯泄漏和扩散行为,并定量评价不同人员环境暴露吸入风险。结果表明：由于气团爬升效应和泄漏速率连续变化,PHAST的计算结果比ALOHA更准确;苯泄漏下风向不同位置的环境暴露风险处于10^（-5）～10^（-4）范围。

英文摘要：

Integration of mechanism model with HAZOP methodology is used to quantitatively assess three major failure events for p-xylene disproportionation unit,such as failure of circulation hydrogen.PHAST and ALOHA are used to simulate benzene release and predict concentration distribution for three accidents.Environmental exposure risk index is used to divide the risk areas.The results show that PHAST is more reliable than ALOHA because cloud rising effects and time-varying release rate are considered in PHAST simulation,and that the environmental exposure risk is in the range 10~（-5）-10~（-4）.