膨胀深冷分离技术在废气治理中的应用

APPLICATION OF EXPANSION CRYOGENIC SEPARATION TECHNOLOGY IN WASTE GAS TREATMENT

烯烃部聚乙烯装置向脱气仓输送物料的工艺气进入脱气仓,通过压力控制系统从脱气仓顶部排入火炬系统,其中含有丁烯、异戊烷和乙烯等有机组分,这些有机组分通过火炬燃烧后向大气排放,不仅造成了资源的浪费,而且造成了环境的污染。2014年烯烃部采用膨胀深冷分离技术,充分利用丁烯和异戊烷沸点高,在低温条件下首先冷凝为液体的特点,以排放气为动力,经过膨胀和两级换热,有效回收了排放气中的丁烯和异戊烷,并回用于生产,降低了装置的物料消耗,减少了VOC的排放,保护了环境,实现了可持续发展。

The process gas conveying materials to the degassing warehouse in the propylene plant of the Olefin Department entered the degassing warehouse. The gas was discharged from the top of the degassing warehouse into the torch system through the pressure control system. The process gas contained organic components such as butane,isopentane and ethylene which were discharged into the atmosphere through the torch after combustion. This was a waste of resources and led to environmental pollution as well. In 2014,the Olefin Department adopted the expansion cryogenic separation technology. Butane and pentane have high boiling points and they condensate into liquid first under low temperature condition. This paper made full use of such characteristics. It took the exhaust gases as the power. Through expansion and two-stage heat exchange,butane and pentane in the exhaust gases were recovered effectively and reused to production. This reduced the material consumption of the plant,decreased the VOC emissions,protected the environment and realized the sustainable development.