Adsorption studies on bleaching of palm-kernel oil with activated bentonite clay

Abstract

Adsorption studies were performed on bleaching of palm-kernel oil (PKO)
with different weight ratios of activated bentonite clay/PKO, ranging from
0.25% to 3% and at different temperatures of 70ºC, 80ºC, 90ºC and 100ºC. The equilibrium data generated were subsequently fitted with Langmuir and Freundlich adsorption models. The Freundlich equation parameters were calculated and the isotherms gave a better fit of the equilibrium data than the Langmuir equation. A study of the temperature effect on the adsorption showed that the isosteric heat of adsorption was a monotonically increasing function of adsorbent loading. Increase in adsorbent loading was found to increase the colour removal as temperature and adsorbent dosage are increased but became constant at increased loading.

Keywords: Adsorption isotherm, bleaching, Langmuir equation, Freundlich
equation, activated bentonite clay, palm-kernel oil.