电化学方法研究微生物表面活性剂对原油乳状液破乳的作用

选用一种微生物表面活性剂分别与 3种破乳剂GE 189、XE 12 0和XP 12 0复配 ,对模拟原油乳状液进行破乳脱水。结果表明 ,微生物表面活性剂的引入能够明显地提高破乳剂的破乳速率和效率 ,而且当破乳剂的浓度较低时 ,微生物表面活性剂的影响更加明显。通过界面张力的测定 ,证实了微生物表面活性剂和破乳剂之间的协同作用。利用电化学方法测定水 油 水界面的膜电容和膜电阻 ,探讨了微生物表面活性剂对原油乳状液破乳效果的影响机理。结果表明 ,单独使用微生物表面活性剂 ,观察不到膜电容和膜电阻的任何变化 ;微生物表面活性剂与破乳剂复配 ,界面膜电容随时间的升高与界面膜电阻随时间的下降幅度明显大于单独使用破乳剂时的情况 ,也表明了微生物表面活性剂与破乳剂之间的协同效应。而且由于微生物表面活性剂的加入 ,引起膜电容的迅速升高和膜电阻的迅速下降与乳状液破乳脱水速率的加快密切相关 ,说明该种电化学方法用于破乳机理的研究是可行的。

ELECTROCHEMISTRY STUDY ON EFFECT OF MICROBIAL SURFACTANT ON DEMULSIFICATION OF CRUDE OIL EMULSION

One kind of microbial surfactant was selected and mixed with three demulsifiers GE 189,XE 120 and XP 120, respectively, to resolved the model crude oil emulsion. The results indicated that the introduction of microbial surfactant could greatly raise the speed and efficiency of water separation from emulsion, especially at lower demulsifier concentrations,the effect of microbial surfactant on water separation from emulsion was more obvious. By means of measurement of interfacial tension, the synergetic effect between demulsifier and microbial surfactant was confirmed. Interfacial film electric capacity ( C m) and film electric resistance ( R m) were measured by electrochemical method, and the mechanism of microbial surfactant on the re solution of model crude oil emulsion was studied. The results showed that no significant effect on C m and R m was observed when only microbial surfactant was used, however, when microbial surfactant was mixed with demulsifier,the increase of C m and the decrease of R m with time were more remarkable than those only demulsifier was used, demonstrating a synergetic effect between microbial surfactant and the demulsifier. In addition, the rapid increase of C m and the rapid decrease of R m were closely related to the increase of water separation speed from model crude oil emulsion as a result of the addition of the microbial surfactant, which showed that the electrochemical method was feasible in studying demulsification mechanism.