摘要：

采用水相聚合法，以甲基丙烯酸、丙烯酸乙酯、苯乙烯为单体，合成聚丙烯酸酯反相破乳剂CR-3，研究乳化剂种类、乳化剂投加量和CR-3有效含量对最终乳液产品稳定性的影响，并初步探索CR-3作为反相破乳剂的作用机理。结果表明，当乳化剂选用十二烷基硫酸钠，其投加质量分数为3%，CR-3有效质量分数为12%时，所得乳液产品的粒径中值为57.5 nm，无渣且稳定性高。反相破乳性能评价表明，该产品清水效果显著。在曹妃甸油田含油污水油水分离的现场试验表明，加注40 mg/L CR-3时，电脱水器出口原油含水率为0.3%，满足油品要求，在核桃壳过滤器之前配合清水剂和浮选剂使用，出水水质满足回注标准，现场各系统运行稳定。机理研究表明，将CR-3投加至含油污水，其分子中的亲油基团（酯基）会吸附在油滴表面，促进分子中苯环、极性基团与沥青质、胶质的芳香结构相互作用，降低缔合体尺寸，进而促进油水分离。

关键词: 聚丙烯酸酯, 反相破乳剂, 界面张力, 作用机理, 油水分离

Abstract:

Polyacrylate reverse demulsifier CR-3 was synthesized with methyl methacrylate, ethyl acrylate, and styrene as monomers by aqueous polymerization method. The effects of emulsifier type, emulsifier dosage, and effective content of CR-3 on the stability of the emulsion product were studied, and the mechanism of CR-3 as a reverse demulsifier was preliminarily explored. The results showed that when sodium dodecyl sulfate was selected as the emulsifier, with dosage mass fraction of 3% and effective mass fraction of CR-3 as 12%, the median particle size of the obtained emulsion product was 57.5 nm, with no slag and high stability. The evaluation of reverse demulsification performance showed that the product had significant effect on water purification. The on-site test of oil-water separation in the oil-polluted water of Caofeidian Oilfield showed that when adding 40 mg/L CR-3, the water content of the crude oil at the outlet of the electric dehydrator was 0.3%, which met the requirements of oil products. Before the walnut shell filter, when it was used in combination with clear water agent and flotation agent, the effluent quality met the reinjection standard, and all systems on site operated stably. Mechanistic studies showed that when CR-3 was added to oil-polluted water, the lipophilic groups(ester groups) in its molecules would adsorb onto the surface of oil droplets, promoting the interaction between the benzene ring and polar groups in the molecule and the aromatic structure of asphaltenes and resins, which reduced the size of the aggregates, and thereby promoted oil-water separation.

Key words: polyacrylate, reverse demulsifier, interfacial tension, action mechanism, oil-water separation

中图分类号: 

• TQ317.3