Optimization of Vegetable Oil Leaching from Spent Nickel Catalyst and Validation of the Results

The optimization of vegetable oil leaching from spent nickel catalyst is reported in this work. Different solvents including; methyl ethyl ketone (MEK), acetone, hexane and toluene were employed. The leaching time in the range 1 to 5 h was studied. The leaching optimization shows that the use of MEK for 3 h provides the best results. This was followed by the recovery of nickel from spent catalysts in the form of nickel sulfate. In pursue of finding a robust, inexpensive, simple and fast technique for on-line concentration measurement of nickel solution from leaching, the spectrophotometer technique was evaluated. The findings were then validated against titration method using EDTA.