A Sustainable Catalysis Process for Converting Acrylic Acid into Methyl Acrylate by Modifying Bentonite with KOH

Abstract

This study investigated potassium hydroxide (KOH) and bentonite as catalysts for producing methyl acrylate via esterification. Bentonite was impregnated with KOH at 1:20 and 1:4 ratios to examine the effect of varying KOH concentrations. X-ray diffraction (XRD) analysis characterized the catalysts and natural bentonite, revealing that impregnation partially converted KOH to potassium oxide (K2O) during calcination, likely enhancing catalytic activity.A catalytic esterification reaction between acrylic acid and methanol was performed to evaluate the KOH-bentonite's performance. Key parameters, including catalyst ratio, reaction time, reactant molar ratio, catalyst concentration, and reaction temperature, were systematically optimized. The KOH-bentonite catalyst with a 1:4 KOH-to-bentonite ratio demonstrated the highest catalytic activity, achieving a 94% conversion of acrylic acid to methyl acrylate. This optimal conversion was attained under specific conditions: a 3-hour reaction time, 10% catalyst concentration, a 1:4 molar ratio of acrylic acid to methanol, and a temperature of 160°C. XRD also confirmed the bentonite's crystal structure remained largely intact after impregnation.These findings confirm KOH-bentonite as an effective solid base catalyst for methyl acrylate production. Future research could focus on improving catalyst reusability, stability, and process scalability to advance a more sustainable and efficient esterification process.