Intensification of Naphthenic Acids Removal by Liquid-Liquid Extraction of Synthetic Offshore Produced Water Using Onboard Fuel

In offshore platforms, elevated costs due to effluent quantity, logistics, space limitation, and availability of solvents hinder produced water treatment, leading petrochemical industries to develop feasible backup strategies to create a sustainable treatment of this byproduct. This context motivates the present study's proposal to use diesel oil in offshore facilities as onboard fuel to remove naphthenic acids (model compound of the dissolved organic fraction) through liquid-liquid extraction. Results achieved out in a separation funnel using synthetic produced water ([cyclohexanecarboxylic naphthenic acid]0 = 500 mg/L) and diesel as an extracting solvent (10%) present high removal efficiencies of about 60% of the cyclohexanecarboxylic naphthenic acid present in synthetic water produced at pH 2% and 42% at pH 4. The characterization analysis of the diesel oil after the liquid-liquid extraction process indicates that it is suitable for reuse as fuel within the offshore platform dispensing further treatments.