以废弃PET塑料为原料制备离子液体破乳剂

Preparation of Ionic Liquid Demulsifier from Waste PET Plastics

汤雨琦 李 欢 李苏曼 胡志杰 颜学敏 余维初 米远祝

TANG Yuqi LI Huan LI Suman HU Zhijie YAN Xuemin YU Weichu MI Yuanzhu

传统以环氧乙烷和环氧丙烷为原料的聚醚类破乳剂需要危险复杂的生产过程，而且破乳性能仍然难以满足实际生产的要求。利用废弃聚对苯二甲酸乙二醇酯（PET）塑料为主要原料，合成了一种用于油包水（W/O）原油乳液脱水的离子液体破乳剂 BADT-IL，采用傅里叶变换红外光谱仪（FT-IR）和核磁共振氢谱仪（1H-NMR）分析了BADT-IL 的化学结构，考察了BADT-IL 浓度、沉降时间、破乳温度、盐度和 pH 值对原油乳液破乳效率的影响，并通过测试界面张力（IFT）、Zeta 电位、三相接触角（CA）、聚结时间和显微观察等多种手段对BADT-IL 在原油乳液中的破乳机理进行了探讨。研究结果表明，在含水率为 70%的原油乳液中加入 250 mg/L 的 BADT-IL， 60 ℃条件下静置 180 min 后破乳效率高达 95.23%；同样的条件下，对含水率为 30%的原油乳液的破乳效率达到99.22%，且分离后水相清澈、油水界面整齐。BADT-IL 具有良好的耐盐性，而且增大盐度能提升破乳效率，在50 g/L 的条件下，含水率为 70%的原油乳液的破乳效率为 96.33%。随着破乳温度的升高，破乳速率显著加快，且破乳效率也随之提高。此外，与常用的商业破乳剂对比，BADT-IL 表现出优异的破乳性能。BADT-IL 在破乳过程中能够有效降低油水界面的 IFT，并取代界面处的乳化剂，形成不稳定的复合界面膜从而促进水滴的聚结，最终实现有效的油水分离。

The production process of traditional polyether demulsifiers using ethylene oxide and propylene oxide as raw materials is dangerous and complicated，and the demulsification performance is still difficult to satisfy the requirements of actual production. In this paper，an ionic liquid demulsifier BADT-IL for the dehydration of W/O emulsion was synthesized using waste PET plastic as raw material. The chemical structure of BADT-IL was analyzed by Fourier transform infrared spectroscopy（FT-IR）and nuclear magnetic resonance hydrogen spectroscopy （1H-NMR）， and the effects of BADT-IL concentration， sedimentation time， demulsification temperature，salinity and pH value on the demulsification efficiency of crude oil emulsion were investigated in detail. The demulsification mechanism of BADT-IL in crude oil emulsions was investigated through various methods including the measurements of the interfacial tension （IFT），zeta potential，contact angle （CA），coalescence time，and microscopic observation. The study revealed that the addition of 250 mg/L of BADT-IL to crude oil emulsions containing 70% water content resulted in a demulsification efficiency of 95.23% after static settling at the temperature of 60 ℃ for 180 minutes. Under similar conditions，demulsification efficiency reached 99.22% in crude oil emulsions with 30% water content，producing a clear separated water phase with a clean oil-water interface. BADT-IL demonstrated strong resistance to salt，with the increase of salinity，the demulsification efficiency improved. At a salinity of 50 g/L，the demulsification efficiency of crude oil emulsions with 70% water content reached up to 96.33% . As the demulsification temperature rose，both the demulsification rate and efficiency increased significantly. Compared to typical commercial demulsifiers， BADT-IL exhibited exceptional demulsification performance. BADT-IL could effectively reduce IFT at the oil-water interface during demulsification，replace the emulsifier at the interface，form an unstable composite interfacial film，facilitate droplet coalescence，and consequently ensures efficient oil-water separation.

10.19346/j.cnki.1000-4092.2024.03.020