聚酯装置酯化工艺塔余热利用集成技术及效益探讨

Integrated technology and economic benefit of steam waste heat utilization in esterification tower of polyester plant

针对400 kt/a聚酯装置酯化工艺塔蒸气余热回收利用不完全的问题,分析了工艺塔塔顶蒸气余热的特点,探讨了蒸气余热利用集成技术及产生的经济效益。结果表明:酯化工艺塔塔顶气相温度约102℃,采用余热利用集成技术可以较好地实现工艺塔蒸气余热回收利用;增加溴化锂制冷机可将蒸气余热制成冷冻水,用于夏季纺丝空调制冷;增设板式换热器可将蒸气余热制成热水,分别用于制热纺丝空调、加热配浆乙二醇;增加蒸发器、冷凝器和膨胀机等可将蒸气余热用于发电;以400 kt/a聚酯装置为例,采用余热利用集成技术回收利用酯化工艺塔塔顶蒸气余热,通过余热制冷、余热制热水、余热发电,每年可节约标煤分别为886.8,669.6,406.5 t,合计可节约标煤1962.9 t。

Aiming at the problem of incomplete recovery and utilization of steam waste heat from the esterification tower of a 400 kt/a polyester plant,the characteristics of steam waste heat from the top of the process tower were analyzed,and the integrated technology of steam waste heat utilization and its economic benefits were discussed.The results showed that the gas phase temperature at the top of esterification tower was about 102℃,and the steam waste heat recovery of process tower can be better realized by using the integrated technology of waste heat utilization;a lithium bromide refrigerator was added to produce chilled water from steam waste heat for air conditioning for spinning in summer;a plate heat exchanger was added to produce steam waste heat into hot water,which could be separately used for heat air conditioning for spinning and heating slurry glycol compound;the steam waste heat could be used for power generation by adding evaporator,condenser,expander,etc.;and taking the 400 kt/a polyester plant as an example,the waste heat utilization integrated technology was used to recover and utilize the steam waste heat at the top of the esterification process tower,and the technologies of waste heat refrigeration and waste heat for hot water production and power generation can save 886.8,669.6 and 406.5 tons of standard coal,respectively,and a total of 1962.9 tons of standard coal annually.