碱酸预处理高含渣污油的破乳机制研究

Demulsification Mechanism of Sodium Hydroxide and Sulfuric Acid Pretreatment for Dirty Oil with High Solid Content

谢志勤 尹必跃 张淮浩

XIE Zhiqin YIN Biyue ZHANG Huaihao

采用碱（NaOH）、 酸（H2SO4）联合破乳剂处理具有高乳化性、 高稳定性的高含渣污油， 在固定破乳剂 SP3用量 （0.8 g/L）、 反应温度 60℃、 反应时间 120 min的条件下， 通过正交实验确定碱、 酸加量 （相对于污油而言） 分别为40 g/L和 25 g/L， 破乳后油层含水率降至 10.6%， 实现了油水渣三相分离。通过测试油层中油、 水、 渣含量， 污油组分， 油层表面张力和黏度， 分析了碱、 酸处理对污油破乳的作用。碱+酸处理后污油中胶质沥青质的含量减少， 破坏了固体颗粒与胶质沥青质形成的网络结构， 有利于固体颗粒从油相中脱附， 促进油滴与水滴的各自聚并； 同时碱+酸处理使得污油的 Zeta电位绝对值减小， 降低了污油的界面膜强度； 在碱+酸+破乳剂处理后污油中固体颗粒的三相接触角从 95.6° 减小至 87.0°， 固体颗粒的表面润湿性被显著增强。碱+酸预处理使污油的黏度、 表面张力及稳定性降低， 碱酸协同破乳剂处理可实现高含渣污油的破乳脱水及脱渣。图 5表 5参 16

Sodium hydroxide and sulfuric acid，combined with demulsifier agent，was employed to treat the high solid content dirty oil with strong emulsification and stability. When the dosage of SP-3 demulsifier was 0.8 g/L，reaction temperature was 60℃ and reaction time was 120 min，the optimal addition amount of sodium hydroxide and sulfuric acid were achieved by orthogonal experiment，being of 40 g/L and 25 g/L，respectively，and after demulsification，the water content in oil layer could be decreased to 10.6%，realizing three-phase（oil，water and solid）separation. From the analytical data，including the content of oil，water and solid in oil layer，dirty oil component，surface tension and viscosity of oil layer，the effect of sodium hydroxide and sulfuric acid on dirty oil demulsification was investigated systematically. Therein，sodium hydroxide + sulfuric acid pretreatment could reduce the content of resin and asphaltene in dirty oil，destroy the net structure formed by solid，resin and asphaltene，make the solid particle separate from oil phase easily，and promote the coalescence of oil droplet and water droplet，respectively. Meanwhile，sodium hydroxide + sulfuric acid pretreatment could decrease the absolute value of Zeta potential obviously，thus lowering the intensity of interfacial film. Furthermore，sodium hydroxide + sulfuric acid + demulsifier could lower contact angle of water on the surface of solid particles in the dirty oil from 95.6° to 87.0°，enhancing the surface wettability of solid particle significantly. Sodium hydroxide + sulfuric acid pretreatment could decrease the viscosity，surface tension and stability of dirty oil. In general，the sodium hydroxide + sulfuric acid pretreatment combined with demulsifier agent can realize demulsification，dehydration and solid removal of the high solid content dirty oil effectively.

10.19346./j.cnki.1000-4092.2017.03.030