Hydrophilic magnetic chitosan/gelatin hydrogel with enhanced fuel dehydration characteristics: Modeling, kinetic, isotherm and thermodynamic study.

Abstract

In this research, a nanocomposite of Fe₃O₄/chitosan/gelatin was prepared and used as a magnetic recyclable dewatering agent to improve the quality of fuel. Prepared materials were characterized by XRD, FT-IR, VSM, BET and FESEM techniques. Effective factors on water uptake i.e., initial water content, time, percentage of Fe₃O₄ and adsorbent dosage were optimized with Box-Behnken design and results showed that all parameters are significant. The performances of three magnetic composites including crosslinked chitosan, functionalized chitosan and chitosan/gelatin showed that magnetic chitosan/gelatin with 13 % of Fe₃O₄ content has a removal percentage of 99.2-97.3 % besides the efficiencies were 35.8-43.8 % and 79.5-89 % using crosslinked chitosan, functionalized chitosan as adsorbents. Results from the kinetic study showed that pseudo - second-order model can better describe water uptake moreover, the adsorption process followed the Langmuir isotherm model. Magnetic chitosan/gelatin composite shows a maximum water removal efficiency of 97.3 % at an initial water concentration of 2500 mgL^-1 after 40 min. The thermodynamic study showed that adsorption is a spontaneous process with higher feasibility at higher temperatures. Moreover, the adsorbent shows a good efficiency of 93.7 % after 6 recycling. These results confirmed good performances of the prepared hydrogel in dehydration to improve the quality of fuel.