常减压蒸馏装置单独加工凝析油中的问题及应对措施

南帕斯凝析油是低硫石蜡基原油，凝点低，轻烃、轻油收率高，硫、氮、金属镍、钒含量低，盐含量较高，加工后是理想的乙烯裂解和催化重整原料。介绍了常减压蒸馏装置的适应性改造情况，工艺路线为凝析油→换热→电脱盐→换热→初馏塔→换热、加热→常压塔，采用减压塔作为吸收塔常压操作备用。最后，从装置评估、储存、原料控制、工艺调整、腐蚀监测等方面分析了装置存在的问题，提出解决的应对措施。单独加工凝析油以来，装置目前并没有出现兄弟企业掺炼带来塔顶系统突出的腐蚀问题，主要是常减压蒸馏装置改造后的加工量较原加工能力大为减少，塔顶馏出量并没有高于设计值；另外，操作条件不同，单炼凝析油时常压塔塔顶温度降低，使塔顶系统管线及换热器未处于腐蚀较重的初凝区。实践证明，只要采取的措施适当，加工凝析油具有成本低、加工费用和效益等几个方面的优势。

Problems in Processing Condensate Oil in Atmospheric-vacuum Distillation Unit and Countermeasures

The South Pars Condensate is a low - sulfur paraffin - based crude oil. As it is a light hydrocarbon which is low in condensing point, high in light oil yield, low in sulfur, nitrogen, Ni and V and high in salt contents, it is a satisfactory feedstock for ethylene cracking and catalytic reforming. The atmospheric - vacuum distillation unit was revamped with the process of South Pars Condensate→heat exchange →electric desalting→heat exchange →primary tower→heat exchange, heating-＋atmospheric tower. Vacuum tower is used for absorption. The problems in unit operation were analyzed in respect of unit operation evaluation, feedstock storage, feedstock control, process adjustment and corrosion monitoring, etc. and effective countermeasures were recommended. Ever since the unit began to process South Pars Condensate, no corrosion has been found in the overhead of distillation tower as the other refiners who blend South Pars Condensate into their feedstock. This is mainly because the operating capacity of the revamped atmospheric - vacuum distillation unit is greatly reduced as compared with that before revamping. The overhead distillation is with the design limit. In the addition, the different operating conditions have been adopted to reduce the overhead temperature of atmospheric tower processing condensate oil, and overhead pipelines and heat exchangers were not in the corrosive primary dew point zone. The practice shows that the application of appropriate measures can reduce the processing costs of condensate oil and improve the economic benefits.