Adsorption of Free Fatty Acid from Crude Palm Oil on Magnesium Silicate Derived from Rice Husk

Authors

  • Weerawat Clowutimon King Mongkut's Institute of Technology Ladkrabang
  • Prakob Kitchaiya King Mongkut's Institute of Technology Ladkrabang
  • Pornsawan Assawasaengrat King Mongkut's Institute of Technology Ladkrabang

DOI:

https://doi.org/10.4186/ej.2011.15.3.15

Keywords:

Adsorption, free fatty acid, magnesium silicate.

Abstract

Magnesium silicate with various silica and magnesium oxide ratios (SiO2/MgO ratios) was used as the adsorbent for a study of adsorption of free fatty acid (FFA) in crude palm oil (CPO). Magnesium silicate was prepared from magnesium nitrate or magnesium sulfate solution precipitated with a solution of sodium silicate derived from rice husk. SiO2/MgO ratios of the magnesium silicate synthesized from magnesium nitrate and magnesium sulfate were 3.93, 3.75, 2.74, 2.40, 1.99 and 3.96, 3.61, 3.51, 2.91, 2.69, respectively. FFA adsorption on the magnesium silicate was carried out by adding 1 gram of the adsorbent to 50 grams of CPO and shaking for 1 hour at 50oC. It was found that SiO2/MgO ratio of 1.99 had the highest adsorption capacities of 185 mg of FFA per gram of adsorbent. In addition, increasing of SiO2/MgO ratios of magnesium silicate was found to reduce the adsorption capacities due to decreasing of FFA chemisorption. The effect of dosage amount to equilibrium adsorption capacities were carried out by adding different amount of magnesium silicate (SiO2/MgO ratio of 1.99) to 50 grams of CPO. The result showed that efficiency decreased when dosage increased. The Fruendlich and Langmuir isotherm were applied to describe this absorption system. The values of maximum sorption capacity (Q0) and Langmuir's sorption affinity (b) in the Langmuir equation obtained by linear-regression were minus values which were physically meanigless. Thus, FFA adsorption on magnesium silicate was both physisorption and chemisorption and well represented by the Fruenlich isotherm.

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Author Biographies

Weerawat Clowutimon

Department of Chemical Engineering, Faculty of Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand

Prakob Kitchaiya

Department of Chemical Engineering, Faculty of Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand

Pornsawan Assawasaengrat

Department of Chemical Engineering, Faculty of Engineering, King Mongkut's Institute of Technology Ladkrabang, Bangkok 10520, Thailand

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Published In
Vol 15 No 3, May 20, 2011
How to Cite
[1]
W. Clowutimon, P. Kitchaiya, and P. Assawasaengrat, “Adsorption of Free Fatty Acid from Crude Palm Oil on Magnesium Silicate Derived from Rice Husk”, Eng. J., vol. 15, no. 3, pp. 15-26, May 2011.