原油低温破乳技术研究

Study on Crude Oil Demulsification Technologies at Low Temperature

锦西石化污水场污油主要来自南蒸馏电脱盐排水带油,严重时电脱盐排水含油高达3%。主要原因是辽河原油中表面活性物质增多,密度、黏度和含水量上升,油水分离变差,只在电脱盐装置使用高温破乳剂已不能满足南蒸馏电脱盐排水达标要求。借鉴其他炼厂罐区低温破乳+电脱盐联合工艺技术方案,选用了栗田、纳尔科和阿克苏三家国外公司4种低温破乳剂,在实验室中,以含水2.56%的辽河原油为原料,恒温60℃沉降2~3d,小试和放大实验表明,10mg/kg破乳剂加入量出水效果最佳,栗田E1020型低温破乳剂出水量最多。参照南蒸馏电脱盐生产条件和原油组成比例,模拟罐区低温破乳+电脱盐联合工艺,实验结果表明,组合工艺优于单独使用电脱盐工艺,并可节省高温破乳剂用量;栗田E1020型低温破乳剂+栗田SR1192型高温剂组合,脱后原油含盐含水最低,电脱盐排水含油量小于200mg/L,在总体费用不增加情况下,预测每年可节省69.02万元。

The slop oils in the wastewater treatment plant at PetroChina Jinxi Petrochemical Company mainly come from the oil-containing wastewater from the electric desahing unit in Distillation Unit I.The oil content of the wastewater from electric desalting unit can be up to 3% in severe case.The main reasons include the increased surface active substances,higher density,higher viscosity,higher water content and poorer oil and water separation of Liaohe crude oil,so only using high-temperature demulsifier in the electric desalting unit can no longer meet the discharge standards of the electric desalting unit in Distillation Unit I.Referring to the combined process scheme of low temperature demulsification and electric desahing for tank farms in other refineries,four types of low temperature demulsifier developed by Kurita,NALCO and Akzo Nobel N.V are se- lected.In laboratory,Liaohe crude oil with a water content of 2.56% is processed under constant temperature of 60~C and settled for 2 to 3 days.The pilot test and scaling up test show that optimum water removal can be obtained while the addition of demulsifier is 10mg/kg,and maximum water removal can be obtained by using Kurita El020 low temperature demulsifier.Referring to the operation conditions of the electric desahing unit in Distillation Unit I and the composition of crude oil ,the combined process of low temperature demulsi- fication and electric desalting for tank farm is simulated,and the results show that the combined process is better than the electric desahing process alone and the consumption of high temperature demulsifier can be reduced.If Kurita E1020 low temperature demulsifier and Kurita SRl192 high temperature demulsifier are used together,the desahed crude oil has the lowest salt content and water content, and the oil content of wastewa- ter from electric desalting unit is less than 200mg/ under the circumstances that the overall cost is not L.h is predicted that 690200Yuan can be saved annually increased.