低温甲醇洗冷量不平衡的分析及优化

Analysis and Optimization of Cold Imbalance in Rectisol Unit

介绍了低温甲醇洗装置的工艺原理和流程,对低温甲醇洗系统的冷量来源与损耗进行了阐述,并简要介绍了平衡冷量的方法。针对装置运行中出现的冷量不平衡问题、中压闪蒸气持续放空以及丙烯机组超负荷问题进行了分析,得出其原因主要是吸收塔下塔流量比过高、丙烯机组冷量提供不稳定,并对现有工艺进行了优化,将吸收塔下塔流量控制在190t/h、丙烯机组一段入口压力控制在135kPa(A)~140kPa(A),达到了冷量的充分利用,实现了中压闪蒸气零放空,并取得了一定经济效益。

The process principle and flow of the rectisol unit was introduced, explaining the cooling source and loss of the low-temperature methanol washing system, and briefly describing the method of balancing the cooling capacity. In view of the problems of cold imbalance in the operation of the plant, continuous venting of the medium-pressure boiloff gas and overload of the propylene unit. The reason was mainly too high flow rate of the lower section of the absorption tower and unstable cold supply of the propylene unit. The existing process was optimized to control the flow rate of the lower section of the absorption tower at 190 t/h and the first-stage inlet pressure of the propylene unit at 135 kPa(A)-140 kPa(A) to achieve full utilization of the cooling capacity, zero venting of medium-pressure boiloff gas, and certain economic benefits.