Coffee Husk Extracts as Sustainable Demulsifiers: A Chemometric Approach to Correlate Molecular Profile and Demulsification Efficiency

High Resolution Image Download MS PowerPoint Slide Petroleum production and refining operations are significantly impaired by the formation of stable water-in-oil emulsions, which require effective chemical demulsification to ensure process efficiency. In this context, coffee husk extracts, an abundant agroindustrial residue, were evaluated as biobased demulsifiers through a systematic chemometric approach. Extracts obtained using different solvents and extraction techniques exhibited distinct chemical profiles, which were characterized by FTIR and HPLC and analyzed by Principal Component Analysis to establish a rational selection of potential demulsifying agents. The chemometric approach efficiently discriminated the extracts according to polarity, functional groups, and key molecular markers, including caffeine, chlorogenic acids, caffeic acid, and trigonelline. This multivariate strategy enabled the identification of specific chemical domains directly associated with emulsion destabilization, shifting the focus from random screening to a structure-performance relationship. Demulsification performance was evaluated in a model lubricating oil/20% NaCl (80:20, v/v) emulsion. The results provided a new insight: the specific molecular profile and amphiphilic balance, rather than total phenolic content alone, govern demulsification efficiency. Notably, ethanol-based ultrasound-assisted extracts achieved robust demulsification efficiencies of up to 75% at 0.1% (w/v) within only 10 min at 80 °C. These findings highlight the importance of targeted molecular polarity and interfacial activity in emulsion breaking and demonstrate that coffee husk extracts are promising low-cost, renewable, and environmentally benign demulsifiers with high potential for rapid petroleum and fuel processing applications.