Garam-Garam Logam Alkali Tanah Silikat Nano Pori Sebagai Adsorben Asam Lemak Bebas dari Minyak Kelapa Sawit Kasar

Abstract

Free fatty acids (FFA) from Crude Palm Oil (CPO) have been adsorbed by alkaline earth metal silicate (M-silicate : M = Mg, Ca, Sr and Ba) adsorbents in ethanol using batch method. The adsorbents were prepared from the chloride salts of alkaline metals and Na2SiO3. The resulting white solid of the alkaline earth metal silicates were then heated at 800oC for 3 hours to enlarge their porosities. All adsorbents were characterized by SEM-EDX, XRD and BET. The EDX spectrum of SEM-EDX showed the appearance of all elements in the adsorbents, and the XRD spectrum of all adsorbents showed that they have crystobalite structure. The porosity of the adsorbents calculated by BET method showed that the porosities of the adsorbents range from 2.0844 - 2.0969 nm as nano pore from nanoparticle. All the adsorbents were used to adsorb the FFA from four tipe CPO each containing 4.79%, 7.3%, 10.37% and 13.34% of FFA. The ratio of adsorbent to CPO to be used in adsorption of FFA from CPO were made 1:1, 1:2 and 1:3, with adsorption time of 1 hour. We found that the maximum adsorption of FFA from CPO was given by Casilicate adsorbent which was between 69.88-94.78%, followed Sr-silcate between 52,07-93,32%, Mg-silicate between 49,34-74,55% while the lowest adsorption was shown by Ba-silicate adsorbent which was 39,53-79,77%.

Asam lemak bebas (ALB) dari minyak kelapa sawit kasar (CPO) diadsorpsi dengan adsorben logam alkali tanah silikat (M-silikat: M = Mg, Ca, Sr dan Ba) dalam pelarut etanol dengan menggunakan metode batch. Adsorben dihasilkan dari reaksi garam-garam klorida logam alkali tanah dan Na2SiO3. Padatan putih logam alkali tanah silikat yang dihasilkan kemudian dipanaskan pada suhu 800oC selama 3 jam untuk memperbesar porositas. Adsorben yang dihasilkan dikarakterisasi dengan menggunakan SEM-EDX, XRD dan BET. Spektrum EDX dari SEM-EDX menunjukkan semua elemen dari adsorben, spektrum XRD menunjukkan bahwa adsorben memiliki struktur crystobalite. Porositas adsorben dihitung dengan metode BET menunjukkan bahwa porositas adsorben berada pada kisaran 2,0844-2,0969 nm sebagai nano pori dari nanopartikel. Semua adsorben digunakan untuk mengadsorpsi ALB dari empat jenis CPO yang masing-masing mengandung ALB sebesar 4,79%, 7,3%, 10,37% dan 13,34%. Perbandingan adsorben dan CPO yang digunakan untuk mengadsorpsi ALB dari CPO adalah 1:1, 1:2 dan 1:3, dengan waktu adsorpsi selama 1 jam. Adsorpsi maksimum ALB dari CPO ditunjukkan oleh adsorben Ca-silikat antara 69,88-94,78%, diikuti Sr-silikat antara 52,07-93,32%, Mg-silikat antara 49,34- 74,55% sedangkan adsorpsi paling rendah ditunjukkan oleh adsorben Ba-silikat sebesar 39,53-79,77%.