Dichloromethane solvent for furfural recovery from potato peels: Thermodynamic and kinetic investigations

Abstract

Objectives. This study aims to investigate the kinetics and thermodynamics of furfural extraction from sweet potato peels using dichloromethane (CH2 Cl2) as a solvent and sulfuric acid as a catalyst. To that end, we set out to determine the kinetic parameters for furfural production using first-and second-order models, optimize the extraction temperature, and evaluate the thermodynamic properties of the reaction. Methods. Potato peels, selected for their high hemicellulose content, cost-effectiveness, and sustainability, were processed with dichloromethane, selected for its safety, low energy requirements, and compatibility with green extraction processes. Experimental conditions involved varying temperatures (60, 70, and 80°C) and peel powder particle sizes (<5 mm), with the reaction being monitored to fit kinetic models and calculate thermodynamic properties. Results. Experimental findings revealed that the first-order kinetic model provided the best fit, with an activation energy (Eₐ) of 85.99 kJ/mol. Thermodynamic analysis showed an enthalpy change (ΔH) of 83.14 kJ/mol, entropy change (ΔS) of −86.08 J/(mol·K), and Gibbs free energy (ΔG) values ranging from 111.80 to 112.66 kJ/mol across the studied temperatures. Optimal extraction conditions were achieved at 80°C, yielding the highest furfural concentration through acid-catalyzed hydrolysis. The energy-intensive yet controlled nature of the reaction highlights the need for further optimization. Conclusions. This study demonstrates the effectiveness of dichloromethane as a solvent for furfural extraction from sweet potato peels under optimized conditions. The kinetic and thermodynamic findings elucidate the reaction mechanism and its industrial applicability. Future studies should focus on simulating furfural separation from ternary solvent systems using Aspen Plus to enhance sustainability and scalability.