Cleaning Spent Bleaching Clay through Using Solvent Extraction Method and RSM Statistical Approach

Bleaching clay refers to clays that in their natural or activated state have the capacity to absorb dyes and other remaining undesirable ingredients from edible oil during its purification processes. Thus, the most important function of bleaching clay is to improve the appearance, flavor, odor, and stability of the final oil product. Hexane, acetone, and methyl ethyl ketone were used as the solvents in this research, and RSM (response surface methodology) was employed for determining the optimal parameters. The variable parameters included the solvent to clay ratio (SCR) and the extraction time. Results showed methyl ethyl ketone with the final oil removal efficiency of 61.3% was superior to hexane and acetone, with efficiencies of 52.7 and 59.1%, respectively. Under the best laboratory conditions and using RSM, the highest extraction efficiency was 5.97 ml/g for the ketone solvents (acetone and methyl ethyl ketone) at the extraction time of 3 minutes and 6 seconds, and 5.92 ml/g for hexane at the extraction time of 24 minutes and 30 seconds. Key words : Cleaning, Spent Bleaching Clay, Solvent Extraction, Response Surface Methodology (RSM), Oil Purification