“…Glycerol can be used as a reactant in oxidation processes, fermentation process, acetylation processes with acetic acid, and acetalization processes with ketones. Valuable chemicals obtained from glycerol include glyceraldehyde, dihydroxyacetone, hydroxyl pyruvic acid glycolic acid, and glyceric acid [7], 1,3-propanediol [8], polyglycerol esters [9,10], and oxygenated acetals and ketals [11][12][13]. Glycerol by-product from biodiesel production can be a source for the preparation of acidic catalysts for utilization in etherification reactions producing oxygenated additives for fuels [14].…”