不同结构破乳剂对原油及其酸碱组分表面膜的影响

 采用Langmuir-Blodgett(L-B)技术测定孤岛原油及其酸碱四组分表面膜膜压随水相破乳剂浓度的变化，考察了4种不同结构的破乳剂对原油及其酸碱四组分表面膜膜压的影响。结果表明，破乳剂对原油及其酸碱四组分的表面膜膜压降低程度与其结构和浓度有关。支链型破乳剂AE8025可以显著降低原油及其酸碱四组分的表面膜膜压，并随着破乳剂浓度的增加，表面膜膜压逐渐降低；其降低酸性分、碱性分和两性分表面膜膜压的程度大于对中性分的。与直链型破乳剂相比，支链型破乳剂降低孤岛原油及其酸碱组分表面膜膜压的能力更强，说明支链型破乳剂对原油及其组分乳状液中界面活性物质的顶替作用更强，破乳效果更优；当破乳剂浓度相同时，破乳剂对原油酸性分表面膜膜压的影响远大于其它3种组分的。

Effect of Different Structure Demulsifiers on the Surface Film Properties of Crude Oil and Its Acidic-Basic Fractions

Langmuir-Blodgett(L-B) technology was used to study the influence of four different structure and concentration of demulsifiers on the surface properties of crude oil and its acidic-basic fractions(acid fraction,base fraction,amphoteric fraction and neutral fraction).The results showed that the surface film pressure decrease range of crude oil and its fractions was related to the structure and concentration of demulsifier.The branch chain demulsifier AE8025 could decrease remarkably the surface film pressure of crude oil and its acidic-basic fractions.With the concentration increase of AE8025,the surface film pressure decreased gradually,in which the surface film pressure decrease of acid fraction,base fraction and amphoteric fraction was more than that of neutral fractions.Compared with straight chain demulsifier,the branch chain demulsifier had stronger ability to reduce the surface film pressure of Gudao crude oil and its fractions,meaning that the more molecules of surface-active fractions at the interface of crude oil and its fractions emulsion were substituted by branch chain demulsifier molecules,so better demulsification effect was obtained.The effect of demulsifier on the surface film pressure of acid fraction was greater than that on other fractions(base fraction,amphoteric fraction and neutral fraction) of crude oil under the same demulsifier concentration.