新疆原油深度脱盐研究 Ⅰ.破乳剂分子结构对脱盐的影响

Study on the Deep Desalting of Xingjiang Crude Oils Ⅰ.Effect of Demulsifiers' Molecular Structure on Desalting Efficiency of Crude Oils

针对新疆原油的性质,在评选的基础上合成出一批酚醛树脂聚氧丙烯、聚氧乙烯醚破乳剂。研究了破乳剂分子结构变化对原油脱盐效率以及油-水界面张力的影响。结果表明:此破乳剂的分子量及亲水基、亲油基比例的变化均对破乳脱盐效果有很大的影响,且有一最佳值。对同一种原油,两个系列破乳刺脱盐效率最高点所对应的亲水-亲油平衡值(HLB)基本相同。随着破乳剂分子结构的变化,脱盐效率与界面张力具有相反的变化趋势。本文提出了此种破乳剂在油-水界面上的吸附状态模型,以便进一步解释实验结果。

Demulsifiers, alkyl phenol-formaldehyde polyoxyethlene polyoxypropylene ethers were synthesized for desalting of Xingjiang crude oils. The effect of molecular structure of the demulsifiers on its desalting ability as well as on the interfacial tension of crude oil-water interface was discussed. The results showed that the desalting efficiency on crude oils is largely affected by the molecular weight and the hydrophilic-lipophilic-balance (HLB) value of the demulsifiers. The best desalting efficiency was obtained at certain value of HLB. It was also shown that for one certain crude the best HLB value of two series phenolic-formaldehyde demulsifiers are close. The interfacial tension has opposite changing tendency with the desalting efficiency. An adsorbing state model of this kind of demulsifiers at crude oil-water interface is suggested to explain the phenomenon above.