Recycling and utilization of waste deep frying oil in leather industry

Abstract

The aim of this work is devoted to exploring recycling and application of the waste deep frying oil in the leather industry as a fatliquoring agent. Acid activated local bentonite clay (~ 8N acid concentration) has been investigated in order to verify its impurities absorbent capacity in the deep frying oil bleaching. The activated sample achieved the ideal bleaching capacity (88.9%) at 3% bentonite dose (based on weight of oil).The bleached oil is sulfated at optimal conditions (15% sulfuric acid based on the weight of oil, 30°C and 2 h stirring time). Sulfated oil is evaluated in order to verify their capacity to be used as a leather fatliquoring agent. The analytical data reveal that the desirable ratio of SO₃ (5.5%) that needed to running the sulfated oil in the fatliquoring process has been attained. The aqueous solution of 10 % sulfated oil (fatliquor emulsion) show a high degree of stability against metallic ions and pH as well as great ability to penetrate the chrome tanned leather, adding mass to the leather. The mechanical properties enhancement, what are recommended to be in the fatliquored leather has been reached. The microscopic examination of the fatliquored leather surface and fiber bundles shows that the tiny fibers are actually coated with a thin film of fat-liquor.