A significant amount of water-in-oil (W/O) emulsion is generated during petroleum extraction. However, the current commercial demulsifiers are expensive to produce and requires high demulsification temperatures, leading to increased energy and economic consumption. To enhance the efficiency of demulsifiers and reduce the cost of demulsifying W/O emulsions, we have successfully developed a novel demulsifier named TCED through a straightforward two-step process. This demulsifier features trimethyl citrate as the hydrophilic core grafted with three hydrophobic chains. Its structure was characterized using EA, FT-IR and H NMR spectroscopy, and the demulsification performance was comprehensively evaluated. At a low demulsification temperature of 40 °C, TCED demonstrated a remarkable demulsification efficiency (DE) of 99.06% and 98.74% in emulsions containing water contents of 70% (E70) and 50% (E50), respectively. Especially, a DE of 100% could be obtained in both E70 and E50 emulsions at a concentration of 600 mg/L. Moreover, TCED displayed a high DE even at high salinity levels of 50,000 mg/L and across a wide pH range of 2–10. Additionally, the phase interface was consistently clear after demulsification. To investigate the demulsification mechanism of TCED, various adsorption kinetics experiments were conducted, including measurements of interfacial tension (IFT), surface tension (SFT), interfacial competitive adsorption, and stability of interfacial film. The results obtained from the experiments indicated that TCED possessed remarkable diffusion and replacement capabilities within the emulsions. As a result, it effectively disrupted the original interfacial active substances, such as asphaltenes aggregates found in crude oil. TCED exhibits a high DE at low concentration and temperature. This characteristic highlights its significant potential for low-temperature demulsification applications in the petroleum industry.

中文翻译：

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新型柠檬酸三甲酯低温破乳剂的合成及破乳性能

石油开采过程中会产生大量的油包水 (W/O) 乳液。然而，目前的商业破乳剂生产成本昂贵，并且需要较高的破乳温度，导致能源和经济消耗增加。为了提高破乳剂的效率并降低W/O乳液的破乳成本，我们通过简单的两步过程成功开发了一种新型破乳剂TCED。该破乳剂以柠檬酸三甲酯为亲水核心，接枝三个疏水链。采用EA、FT-IR、H NMR等手段对其结构进行了表征，并对其破乳性能进行了综合评价。在 40 °C 的低破乳温度下，TCED 在含水量为 70%（E70）和 50%（E50）的乳液中表现出显着的破乳效率（DE），分别为 99.06% 和 98.74%。特别是，E70和E50乳液在浓度为600 mg/L时均可获得100%的DE。此外，即使在 50,000 mg/L 的高盐度水平和 2-10 的宽 pH 范围内，TCED 也表现出高 DE。此外，破乳后相界面始终清晰。为了研究TCED的破乳机理，进行了各种吸附动力学实验，包括界面张力（IFT）、表面张力（SFT）、界面竞争吸附和界面膜稳定性的测量。实验结果表明TCED在乳液中具有显着的扩散和置换能力。结果，它有效地破坏了原始的界面活性物质，例如原油中发现的沥青质聚集体。 TCED 在低浓度和温度下表现出高 DE。这一特性凸显了其在石油工业低温破乳应用中的巨大潜力。