Preparation of Mg, Ca, Sr and Ba-based silicate as adsorbent of free fatty acid from crude palm oil

Abstract

In present work, alkaline silicate based on Ba, Ca, Mg and Sr were used as adsorbent for free fatty acids (FFA) removal to improve the quality of shelf-life in crude palm oil (CPO). Environmentally friendly alkaline silicate was successfully prepared using low-cost and facile preparation by sol-gel method annealed at 600, 700 and 800 °C for comparison. Several characterization namely scanning electron microscope (SEM), x-ray diffraction (XRD), fourier-transform infrared spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET) surface area were used to characterize the alkaline silicate morphology, crystallinity, functional group and porosity, respectively. Based on experimental result, the FFA removal and carotene value of CPO were evaluated, it is found that MgSiO 3 annealed at 600 °C demonstrate the highest FFA removal percentage of 95% and carotene can be preserved around 45% due to high surface area of 420.2 m 2 /g, which is superior compared to BaSiO 3 , CaSiO 3 and SrSiO 3 . This can be due to the high surface area with large adsorption sites of granular structure of MgSiO 3 and crystallinity. Thus, this finding gives new pathways of alkaline silicate annealed at low temperature can be used efficiently for future biodiesel applications.