Esterification of Palm Fatty Acid Distillate Using Heterogeneous Sulfonated Microcrystalline Cellulose Catalyst and Its Comparison with H2SO4 Catalyzed Reaction

Abstract

The kinetics of esterification of palm oil fatty acid distillate (PFAD) with methanol was investigated using heterogeneous carbonized microcellulose sulfonic acid as catalyst and compared with the sulfuric acid catalyzed reaction, considering liquid–liquid phase split during the progress of the reaction in both the cases. The solid catalyst was characterized for acidity, thermal stability, and surface area. The residual glycerides in the PFAD were hydrolyzed prior to the esterification using sulfuric acid as a catalyst. The esterification reaction was investigated for the effect of catalyst loading, temperature, and free fatty acids (FFA) to methanol ratio, on the conversion of the fatty acids. Sulfuric acid was a better catalyst than sulfonated microcrystalline cellulose, but the solid catalyst provides the ease of recovery. The sulfonated microcrystalline cellulose rendered good conversion and reusability for esterification. The process engineering aspects of the esterification reaction are also briefly discussed.