Integrated Conversion of Coconut and Palm Oils into Bio-Based Chemicals via Hydrolysis and Kolbe Electrolysis

Abstract

This study presents an integrated two-step synthetic protocol for the conversion of coconut and palm oils into high-value bio-based hydrocarbons, alcohols, and aldehydes. The process employs alkaline hydrolysis followed by Kolbe electrolysis. Under reflux in an EtOH-KOH system, both oils were quantitatively converted into their constituent fatty acid mixtures (C16–C18:1 for palm oil and C8–C18:1 for coconut oil) with yields up to 88% and 92%, respectively. The resulting intermediates were characterized via GC–MS. Subsequently, galvanostatic Kolbe electrolysis (100 mA) was performed using custom platinum electrodes in binary and ternary solvent systems. High substrate conversions (>86%) were obtained, and the organic product distribution reached up to 73% and 74% relative hydrocarbon selectivity for palm and coconut oil derivatives, respectively, in a ternary MeOH/EtOH/H2O system. However, operating under excess charge yielded isolated hydrocarbon mass yields of 8–20% (with up to 18% Kolbe dimers) alongside medium- and long-chain alcohols and aldehydes. This integrated protocol demonstrates a scalable and tunable route for converting vegetable oils into high-purity bio-based chemicals.