原位接枝纳米炭黑水包油型破乳剂制备与性能评价

Synthesis and Performance Evaluation of In-situ Grafted Carbon Black Nanoparticle as Demulsifier for Treating Crude Oil-in-water Emulsions

采用无溶剂法对工业炭黑进行原位接枝改性,制备了水分散性良好的两亲性胺基化炭黑纳米颗粒(CB-DEA)。采用红外光谱(IR)、X射线光电子能谱(XPS)、原子力显微镜(AFM)和场发射高分辨投射电镜(HRTEM)对CB-DEA结构进行表征。瓶试法破乳实验结果表明,室温下CB-EDA在最佳破乳剂剂量下能实现含油量为10.0%(质量分数)的模拟原油采出液(pH=8.9)的快速破乳,破乳效率高达99.90%以上,脱出水中的含油量低至53.45 mg/L。进一步的研究表明,CB-EDA对高pH值采出液的破乳效果和破乳速率明显高于氧化石墨烯(GO)、还原氧化石墨烯(rGO)和羟基化炭黑(CB-PVA)。ζ电位和破乳机理实验表明,CB-EDA加入油水乳状液后不仅能快速迁移到油/水界面,通过与形成油水界面膜的主要成分沥青质产生强的π-π/n-π相互作用破坏油水界面膜;同时ζ电位为正有利于破乳剂压缩分散油滴表面双电层,加速分散油滴絮凝聚集,促使油水乳液快速分离。本研究克服了两亲性纳米碳基破乳剂的缺陷,发展的CB-EDA有效提高了碳基破乳剂的破乳效率和普适性。

The good aqueous suspensions of amphiphilic aminated carbon black nanoparticles(CB-EDA)are prepared via situ grafted methodby industrial carbon black for treating 10.0wt%crude oil in water emulsions(pH=8.9).The structure and morphology characterization of CB-EDA were explored by Fourier transform infrared spectroscopy(IR),X-ray photoelectron spectroscopy(XPS),Atomic force microscopy(AFM),and high-resolution transmission electron microscopy(TEM).Encouragingly,the demulsification tests indicated that the residual oil in separated water samples was as low as 53.45 mg/L,corresponding to a demulsification effect of over 99.90%at optimum dosage.Besides,the CB-EDA,graphene oxide(GO),reduced graphene oxide(rGO),and hydroxylated carbon black(CB-PVA)for detachment oil from the crude oil-in-water emulsion under alkaline conditions are studied.The zeta potential measurement and mechanism analysis results revealed that CB-EDA has better demulsification efficiency and universality than other nanocarbon-based demulsifiers at ambient temperature.As an amphiphilic nanocarbon-based material,the CB-EDA prefer to migrate to the oil/water interface after add into emulsions adding once CB-EDA is reached at the oil/water interface which can displace the emulsified molecules of the emulsion by strongπ-π/n-πinteraction.More importantly,the zeta potentials are CB-EDA is positive,which can compress double electric layer of dispersed oil droplets to promote emulsified oil droplets accumulation.In the current work,we overcame the disadvantages of the nanocarbon-based demulsifiers,effectively improved their efficiency and universality,and developed a promising CB-EDA demulsifier for the separation of O/W emulsion.