Crude glycerine

Detergents, synthetic organic and inorganic alkaline Dishwashing compounds Dye-removing cream, soap base Glycerin, crude and refined ... 

Commercially glycerin is obtained as a byproduct in the manufacture of soap, and by various synthetic routes. Crude glycerin is purified by distillation. The various synthetic routes start with propenc. One proceeds via... 

Bournay, L., Casanave, D., Delfort, B., Hillion, G. and Chodorge, J.A. (2005) New heterogeneous process for biodiesel production a way to improve the quality and the value of the crude glycerin producedby biodiesel plants. Catal. Today, 106, 190. 

This is a batch reaction carried out at atmospheric pressure with refluxing methanol. The crude reaction mixture is phase-split, and commercial glycerine is recovered from the lower phase by separating excess methanol. 

To achieve better conversions in less time, several common acid, base and transition metal catalysts were screened for the purpose of lowering the reaction temperature in the glycerin process. The results for each category of catalyst are represented in Figure 6.6. All reactions were performed with crude (neutralized) glycerin. The activity of the catalysts is compared based on a standard reaction time at 180 °C for 4 hours and normalized based on equal equivalents of metal content per moles of acid. The organo-metal catalysts, tetrabutyltitanate (TBT), dibutyltin oxide (DBTO), and tinoxalate (SnOx) were the most efficient catalysts. Overall, while tin compounds are effective catalysts, they can be problematic because of their potential toxicity, unless they can be removed from the product in a cost effective manner. 

Glycerin by the Epichlorohydrin Process. In the ECH process, synthetic glycerin is produced in three successive operations, the end products of which are allyl chloride, ECH, and finished glycerin, respectively. Glycerin is formed by the hydrolysis of ECH with 10 percent caustic. Crude glycerin is separated from this reaction mass by multiple-effect evaporation to remove salt and most of the water. A final vacuum distillation yields a 99+ percent product. 

Splitting, or the hydrolysis of triglycerides is usually performed with high-pressure steam, resulting in the formation of split crude fatty acids and glycerin. The production of fatty acids by more sophisticated splitting processes, such as hydrolysis of fatty methyl esters, ozono lysis of unsaturated fatty acids, and chemical oxidation is practiced in special situations. 

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