V2I11P57

Kinetic and Thermodynamic Evaluation of Methyl Ester Sulfonate (MES) as an Eco-Friendly Emulsifier for Enhanced Oil Recovery (EOR)

Syamsuddin, Jusman

Abstract

The decline in oil recovery efficiency from mature reservoirs highlights the global demand for sustainable and environmentally friendly surfactants. Their low biodegradability and ecological risks limit the use of conventional petroleum-based emulsifiers. This study aims to examine the kinetic and thermodynamic characteristics of palm-oil-derived Methyl Ester Sulfonate (MES) as a biodegradable emulsifier for Enhanced Oil Recovery (EOR). Emulsification tests were performed across a range of pH values (5–11), salinity levels (0–5 wt% NaCl), temperatures (40–80 °C), and MES concentrations (0.1–1.0 wt%). The kinetics of emulsification were modeled using a second-order rate equation. The emulsification process conformed to second-order kinetics with correlation coefficients (R²) above 0.98. The rate constant (k) varied from 0.012 to 0.026 s⁻¹, increasing with temperature and alkaline pH, signifying a thermally activated process. Optimal emulsification was achieved at 0.3 wt% MES, pH 9, and 3 wt% NaCl, resulting in droplets smaller than 10 μm that remained stable for 24 hours without coalescence. The activation energy (Eₐ) obtained from the Arrhenius relationship was 18.6 kJ·mol⁻¹, lower than that of conventional surfactants (~25 kJ·mol⁻¹), reflecting enhanced thermodynamic efficiency. The findings confirm that MES is a practical, biodegradable alternative to petroleum-based surfactants and holds strong potential for sustainable chemical EOR applications.

Keywords:

Methyl Ester Sulfonate (MES); Emulsification Kinetics; Enhanced Oil Recovery (EOR); Interfacial Tension; Green Surfactant; Droplet Stability.