蒸馏装置优化操作降低石脑油初馏点、减少石脑油罐区VOCs排放

Optimized Operation of Distillation Unit to Decrease the Initial Boiling Point of Naphtha and Reduce VOC Emissions from Naphtha Tank Farm

挥发性有机化合物(VOCs)常温下蒸发速率大,直接排放不仅会作为光化学反应的前体,产生光化学烟雾和二次有机气溶胶,影响环境,而且因其一部分组成为有毒、有害物质,会损害人体健康。独山子石化10.0Mt/a常减压蒸馏装置的石脑油罐区轻端组分含有硫醇、硫醚等,异味较大,为应对新环保法规的要求,通过优化蒸馏脱丁烷塔顶及常压塔顶操作,将脱丁烷塔顶压力由1.18MPa降低至1.1MPa,脱丁烷塔顶温度由74℃提高至76℃,脱丁烷塔底温度由183℃提高至190℃,石脑油初馏点由42℃提高至49℃,蒸馏装置石脑油收率由25.21%降低至24.6%,同时液化气收率由1.3%上升至1.82%,有效地将石脑油中的轻端组分深拔进入液化气内,降低了石脑油中的轻组分含量。优化操作减少了石脑油罐区VOCs排放,实现了炼油厂安全、健康、环保运行。

Volatile organic compounds （VOCs） has high evaporation rate at normal temperature.In the case of direct emission,it not only produces photochemical smog and secondary organic aerosols as the precursors of photochemical reaction to affect the environment,but also brings harm to human health due to the toxic and harmful substances it contains.The light ends from the naphtha tank farm of the 10.0Mt/a CDU/VDU at PetroChina Dushanzi Petrochemical Company contain mercaptan and thioether and have a bad odor.To meet the more stringent requirements of new environmental protection laws and regulations,the operation tanizer and atmospheric distillation tower is optimized debu- to decrease the overhead pressure in debutanizer from 1.18MPa to 1.1MPa,increase the overhead temperature in debutanizer from 74℃ to 76℃,increase the bottom temperature in debutanizer from 183℃ to 190℃ ,increase the initial boiling point of naphtha from 42℃ to 49℃ ,reduce the naphtha yield in distillation unit from 25.21% to 24.6%,and improve the LPG yield from 1.3% to 1.82% ,thus effectively reducing the light ends content of naphtha.The optimized operation can re- duce the VOC emissions from naphtha tank farm and eration of the refinery. achieve the safe,sound and environmental-friendly operation of the refinery.