A Sustainable Approach to Enhanced Oil Recovery via Cerium-Modified Sugarcane Bagasse Biochar-Stabilized Nanoemulsion

The current article investigates the potential of cerium oxide-modified biochar, derived from sugarcane bagasse, as a novel approach for enhanced oil recovery (EOR) through the stabilization of nanoemulsions. X-ray diffraction analysis confirmed the successful incorporation of CeO2 nanoparticles into the biochar, revealing characteristic peaks of CeO2. Brunauer–Emmett–Teller analysis demonstrated that the modified biochar (BC) exhibited a significantly increased surface area of 310 m2/g, compared to 180 m2/g for the unmodified biochar. Nanoemulsions formulated with n-heptane and stabilized by BC-CeO2 nanoparticles showcased high kinetic stability, with initial zeta potential values ranging from −70 mV to −80 mV. Dynamic light scattering measurements revealed a reduction in droplet size to an average of 300–500 nm, analyzed using statistics. Interfacial tension measurements indicated a significant reduction from 38.3 to 2.8 mN/m upon the addition of BC-CeO2 nanoparticles. Rheological studies demonstrated shear-thinning behavior that is advantageous for EOR applications. Notably, viscosity increased with temperature due to the formation of worm-like micelles at elevated temperatures. Viscoelastic analysis revealed that the nanoemulsions maintained a balance between solid-like and liquid-like behavior, essential for preserving emulsion integrity under reservoir conditions. This research highlights that BC-CeO2-stabilized nanoemulsions represent a sustainable and effective alternative to conventional surfactants in EOR processes.