Pemac Projects Pvt Ltd

Spent Earth Extraction Plant

What is Spent Bleaching Earth?

Spent Bleaching Earth is solid waste material generated as a part of the refining process in the edible oil industry, worldwide. Spent Bleaching Earth is usually disposed of in landfills or waste dumps. Due to increasing cost of disposal and being as environmental hazard, it is desirable to recover oil using a solvent Extraction process in an efficient and economical manner, before disposing off spent Bleaching Earth as per environmental regulations. In refining, bleaching earth is used to remove colour, metal, phosphatides, oxidized products and residual gums from the oil; however, in turn it absorbs approximately 20-40 % by weight of the spent Bleaching Earth.


The oil recovered immediately after the bleaching process by extraction with a solvent can be used as feedstock to a refinery. Otherwise it can be reused as a raw material for industrial applications to save costs in the processing industry. As the residual oil has a very high FFA and Peroxide value, it can only be used for non-food application, as feed stock for conversion to biodiesel, and as a lubricant base for bio-lubricants as a feedstock to the oleo chemical industry. In our process, the oil can be recovered from spent Bleaching Earth using both a flammable as well as non-flammable solvent, which has been done for the first time in the world.