Techno-Economical Evaluation of... 115 Techno-economical Evaluation of Oil Recovery and Regeneration of Spent Bleaching Clay

ABSTRACT. Edible-oil refining industries in Saudi Arabia have expanded con-siderably in the last twenty years. The major waste generated by these indus-tries is spent bleaching clays. It is estimated that about 6000 ton of this waste is generated annually. The cost of the disposed bleaching clay along with oil it contains (20-40 % of the spent clay weight) are major costs of refining. Further-more, the disposal of spent bleaching clay in landfills can cause environmental pollution problems in addition to being a source of odors and fire hazards. This paper describes a process for the recovery of oil from spent bleaching clay by solvent extraction followed by reactivation of the deoiled clay by acid treatment. Also, a preliminary cost estimation of the suggested process was presented for a plant which can process 4800 ton/year of spent bleaching to produce 3600 ton/year of reactivated spent bleaching and 800 ton/year of re-covered oil. The study indicates that the suggested process is economically vi-able. The return of investment was estimated to be 25%. 1