BOYCE ACTIVATED CARBON IN THE MANUFACTURING OF PURE OIL
BOYCE ACTIVATED CARBON IN THE MANUFACTURING OF PURE OIL
The best decoloration takes place using a ratio of 60 percent bleaching earth and 40 percent powdered carbon. Bleaching takes place as a rule at higher temperatures (between 75-115C). This is done in a vacuum, so that the oil and the coloring matter are not able to oxidize. The dosing of the carbon/bleaching earth mixture lies between 0.5 and 1.5 percent by mass. For the removal of PAHs, the usual powdered carbon dosage is 0.25 percent by mass. For seriously contaminated edible oil, the dosing necessary may be 1.5 percent by mass. Where normal bleaching times can take twenty to thirty minutes, the process time for removing PAHs can rise to about 45 minutes. Although chemically activated carbon gives good decoloration, the preference goes to steam activated carbon. This provides a better compromise between the desired decoloration and the unwanted oil loss in the filter cake. Steam-activated carbons are also outstanding at removing light and heavy polycyclic aromatic hydrocarbons. The Boyce Steam activated carbon is used worldwide for the bleaching of edible oils. This type offers a good compromise between the desired adsorption and the unwanted oil loss.