SILICA REFINING OF PALM OIL

The amount of bleaching earth required in the physical refining proces s of palm oil depends on the activity of the earth, quality of the oil and final color specification of the refined products. The use of sil ica (Trisyl) in combination with bleaching clay in palm oil refining h as been investigated. The optimum conditions required for Trisyl and b leaching clay are 95-105 degrees C for a period of 30-40 min. Improvem ents in color performance for palm oil products are noted with the add ition of small quantities of Trisyl (0.060.24%) to the bleaching clay. Addition of 0.12% Trisyl to 0.4% bleaching clay improved the color of the refined oil by as much as 1.7 Red Lovibond units. Lower phosphoru s levels (18.4 and 16.9 ppm) were obtained in the refined oils with an addition of 0.12 and 0.24% Trisyl, respectively, as compared to a lev el of 36.2 ppm of phosphorus when no silica was added to the earth. Be tter color stability was also obtained with oils treated with Trisyl. An additional advantage was the reduction in filtration time, leading to possible higher throughput in refining.