Abstract

Alternative processes for the clarification of used cooking oil (UCO) and the discoloration of red palm oil (RPO) were evaluated. The clarification of UCO consisted of two steps, sediment removal and bleaching. In the first step, three methods were tested: heating, washing with brine, sedimentation and filtration; sedimentation alone; and washing with brine, sedimentation and filtration. The third method allowed the highest removal of impurities. For the second step, three methods were proved: adsorption with activated carbon (AC); ozonation, and application of hydrogen peroxide. The best method was ozonation, with a dose of 0.1946 mol O3/L and a post-treatment temperature of 60 °C; a 24.39% discoloration was reached. Regarding RPO, the best treatment was the adsorption with activated carbon. The ratio of oil: AC that produced the best results was 25:1; a 90.48% color decrease was achieved. The analysis of the quality parameters measured in the treated oils (acid value, saponification value, color and suspended solids) determined that both could be used as raw material for manufacturing soap.