Reduction of Free Fatty Acid Content in Crude Palm Oil Using Acid-Activated Natural Zeolite as a Low-Cost Adsorbent

Abstract

Excessive free fatty acid (FFA) content is a critical quality concern in crude palm oil (CPO) because it accelerates hydrolytic deterioration and increases the refining burden before further processing. This study evaluated acid-activated natural zeolite as a low-cost adsorbent for reducing FFA content in CPO using a laboratory-scale batch adsorption process. Natural zeolite was washed, dried, sieved to 80 mesh, and chemically activated using hydrochloric acid at different concentrations. The adsorption experiments were conducted by varying zeolite dosage, HCl activation concentration, and operating temperature. The process was carried out at 575 rpm for 1 h, followed by centrifugation and FFA determination by titration using 0.05 N KOH. The results showed that FFA reduction was affected by zeolite dosage, acid activation concentration, and temperature. The most favorable condition was obtained using 15% zeolite activated with 4.5% HCl at room temperature, reducing FFA content from 3.5% to 2.5%, corresponding to a reduction efficiency of 28.57%. Room-temperature treatment performed better than treatment at 60 °C, suggesting that mild operating conditions may be more suitable for this adsorption system. These findings indicate that acid-activated natural zeolite can be considered a simple and low-cost adsorbent for reducing FFA content in CPO.