Synthesis and Characterization of Biobased Demulsifier from Coconut Oil for the Treatment of Water-in-Crude Oil Emulsion

Amid growing environmental urgency, the quest for sustainable, high-performance alternatives to petroleum-based demulsifiers has reached a critical juncture. This study unveils a novel coconut-oil-derived demulsifier (COSD), a renewable, eco-conscious solution designed to be used for the treatment of water-in-oil emulsions. Synthesized via a catalytic reaction between coconut oil and diethanolamine, COSD was rigorously characterized using gas chromatography–mass spectrometry (GC-MS), Fourier transform-infrared spectroscopy (FT-IR), and thermogravimetric analysis/differential thermal analysis (TGA/DTA), confirming its robust thermal stability and unique molecular architecture. Bottle-test evaluations revealed exceptional performance: COSD achieved 99% ± 0.3% separation efficiency (SE) in just 360 min at 3000 ppm under static conditions. Notably, at 70 °C, this efficiency was reached within 30 min using only 1000 ppm. Under high-stress dynamic conditions (2,000 rpm), COSD delivered over 90% ± 0.4% separation in 10 min at ambient temperature. The surface tension (ST) and interfacial tension (IFT) are significantly reduced in the presence of COSD. The presence of 3000 ppm of COSD reduces ST and IFT from 72.0 ± 0.2 mN/m and 28.5 ± 0.3 mN/m to 29.7 ± 0.4 mN/m and 10.8 ± 0.3 mN/m at 30 °C. The IFT decreases from 25.3 ± 0.4 mN/m to 7.8 ± 0.2 mN/m at 70 °C, corresponding to a SE of 99% ± 0.3%. Compared with other biobased demulsifiers such as corn oil-derived demulsifiers, COSD demonstrates significantly improved separation kinetics and dosage efficiency. These findings underscore COSD’s practical potential as a scalable and eco-friendly alternative for emulsion treatment in crude oil processing.