0.2 Mt/a催化裂化装置用能分析与改进

借助物料衡算、热量衡算、动量衡算和能量平衡、火用平衡的三环节理论,对催化裂化装置的反应-再生系统进行计算分析。结果表明,过量主风和补燃干气造成烧焦罐线速高、停留时间短、氧浓度低和水蒸气分压大,导致催化剂活性降低,烧焦利用热减少和回收利用率低,装置能耗增加。通过降低主风、停烧干气、减小回炼比和提高剂油比等措施降低工艺总用能;改造余热锅炉,以提高能量转化效率;优化换热、减少过程火用损和热损失等改善能量回收率,可降低能耗31.04%,节能效果明显。

Energy consumption analysis and improvement of 0.2×106 t/a catalytic cracking unit

Based on the three-link theory of the material balance, namely heat balance, momentum balance, and exergy balance, the reaction-regeneration system was calculated. Results showed that excessive fluidization air and burning dry gas would lead to high velocity, short residence time, low oxygen concentration and high partial pressure of steam in the coke-burning drum. Meanwhile, it would reduce catalyst activity, the burning heat and reutilization of exhaust-heat boiler, which caused the increasing of unit energy consumption. By decreasing the air flow, stopping burning the dry gas, reducing gasoline recycle ratio and increasing the ratio of catalyst to oil, the energy consumption can be reduced. The energy transforms efficiency was improved by reforming the waste heat boiler which could optimize the heat exchange, reduce the heat transfer exergy loss and so on. The energy-saving effect is obvious and the total energy consumption of devices reduced by about 31.04%.