ACTIVATED CARBON TO REMOVE POLLUTANTS
FROM EDIBLE OILS:
Activated carbon or activated charcoal is used during the bleaching process of edible oil refining. It employs physical adsorption as a method to purify vegetable oils and make them suitable for consumption. Activated carbon is employed alongside bleaching earths for refining and decolourisation of oil.
Activated carbon is useful for high concentrations of pigments such as chlorophylls, xanthophylls and carotene to improve the bleaching effect or support the thermal decomposition of pigments during deodorisation. Activated carbon is produced from carbonaceous sources, which can include coal, coconuts, nutshells, peat, wood and lignite. The source can be any organic material with a high carbon content. The organic raw material is physically modified and thermally decomposed in a furnace to produce the activated carbon.
CHALLENGE AND SOLUTION:
Many Edible oils can be contaminated with natural and anthropogenic compounds, some of which are carcinogenic, including polycyclic aromatic hydrocarbons (PAH), and polychlorinated biphenyls (PCB), heavy polyenoic aromatics (HPNA), dioxins, furans, pesticides and herbicides. Oils can become contaminated through environmental pollution, drying with combustion gases, associated smoke drying or contamination of transport containers.
These contaminants must be removed to make processed edible oils fit for human consumption given the serious health effects posed by these contaminants. Edible oils are derived from many sources. Another important goal in this application is the removal of unwanted colours from oils. For biological oils derived from fish and plants, activated carbon is the preferred technology for decolorization as bleaching earth is no longer permitted for this purpose.