DECOLORISATION OF CRUDE PALM OIL BY ACID-ACTIVATED SPENT BLEACHING EARTH

Regeneration of spent bleaching earth by acid activation and heat trea tment has been investigated. Spent bleaching earth was activated by H2 SO4 of various concentrations (1-40%) and heat treated at 120 degrees C-350 degrees C. The experimental results indicate that treatment of s pent bleaching earth with 10% H2SO4 at 350 degrees C produced a materi al which was most effective in removing coloured pigments from crude p alm oil. Subsequent experiments were conducted using this particular a cid-treated spent bleaching earth. Various parameters which affect the sorption process were studied. They include initial crude palm oil co ncentration, sorbent dosage and temperature. Applicability of both the Freundlich and Langmuir isotherms to the acid-treated spent bleaching earth-palm oil hexane miscella system indicates that both physiosorpt ion and chemisorption were involved in the sorption process. Measureme nts of various quality parameters of bleached and crude palm oils were carried out. They include Lovibond Colour index, carotene content, pe roxide value, free fatty acid, fatty acid composition and iodine value . The results show that the bleached palm oil retained good oil qualit y after the decolorisation process using 10% acid-treated spent bleach ing earth with a Lovibond Colour of 6.4. (C) 1998 SCI.