TITLE:
Removal of Pigments from Palm Oil Using Activated Ibusa Kaolinite: Equilibrium, Kinetic and Thermodynamic Studies
AUTHORS:
Vincent Nwoye Okafor, Ikechukwu Abuchi Nnanwube, John Ifeanyi Obibuenyi, Okechukwu Dominic Onukwuli, Regina Obiageli Ajemba
KEYWORDS:
Kaolinite, Bleaching, Kinetics, Palm Oil, Thermodynamics
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.7 No.4,
July
22,
2019
ABSTRACT: The effectiveness of Ibusa kaolinite as an
adsorbent in removing pigments from palm oil has been investigated in this
study. Ibusa kaolinite was prepared as an adsorbent by treating it with
hydrochloric acid. The surface area of the clay was found to increase with
increase in acid dosage up to a maximum and then de-creased while its cation
exchange capacity decreased with increase in acid dosage. The activated clay
was used as an adsorbent for the removal of pigments from palm oil. The
bleaching process was investigated by varying the clay dosage, acid
concentration and temperature. The highest removal of pigments was recorded at
7 M HCl concentration, 4 g clay dosage and 100°C temperature, and about
97.4% pigments were removed in 80 minutes. Four isotherm models, three kinetic
models, and the intra-particle diffusion model were applied to fit the
experimental data. It was found that the equilibrium data were best represented
by the Temkin isotherm model. The experimental data fitted well the
pseudo-second-order kinetic model. Diffusion studies indicated that
in-tra-particle diffusion is not the sole rate-controlling factor. The
bleaching pro-cess was found to be spontaneous and endothermic, with increasing
random-ness of adsorbed species.