Glycerin, purification

Singhabhandhu, A. Tezuka, T. A perspective on incorporation of glycerin purification process in biodiesel plants using waste cooking oil as feedstock. Energy 2010, 35, 2493-2504. 

It is also possible to treat allyl chloride with HOCl, transforming it to glycerin dichlorohydrin which, on action of NaOH, yields crude dilute glycerol consisting of a mixture of glycerol and NaCl in water. Final steps in the process are those of concentration, desalting and purification... 

The mixture from the reactor enters a separator where the glycerine in excess of 90% concentration is removed. The methyl ester is subsequently fed to a distillation column for purification. Further fractionation into special cuts may follow if desired (15). 

The purification of glycerine from these sources is obtained using the traditional methods outlined in this chapter. However, the economics of production of the crude glycerol will determine how these new sources affect the world market. 

Peel-off masks are applied in a uniform layer on the skin and upon drying and removal produce a sensation of skin tightness and cleansing action. Peel-off masks are marketed to consumers with normal, oily, combination, and acne-prone skin types. These masks are believed to perform the functions of skin exfoliation, hydration, and purification. They are based on plasticized polyvinyl alcohol. Hydrophilic emollients (e.g., ethoxylated fatty acid or alcohol derivatives, dimethicone copolyol) and humectants (e.g., glycerin, propylene glycol, sorbitol) are added to prevent moisture loss and cracking of polyvinyl alcohol film. Solvents... 

However, the value of the alcohol at tlie jjresent price should balance the cost of all material and overhead charges entering into the production of the fermented wash so that the only cost to be considered for the glycerine would be that of purification and distillation. 

Experiments have also been carried out with cane sugar and starch glucose as fermentable material. It was found necessary in these cases to employ yeast foods that dcle-teriously influenced the purification of the glycerine. It was therefore concluded that these materials had uo superiority over molasses for the purpose. 

Production can be further increased if there are two people to man the production line. The most fruitful way to divide labors in such a situation is for one person to devote himself to running the synthesis reaction between the glycerin, nitric acid and sulfuric acid, and for the other person to man the purification operation. With this division of labors, production can easily exceed a quart per day without resorting to larger batch sizes. 

Butyric acid is obtained from the animal charcoal wluch has been used in the purification of glycerin, in which it exists as calcium butyrate. It is also formed by subjecting to fermentation a mixture composed of glucose, water, chalk, and cheese or gluten. The calcium butyrate is decomposed by H,SO, and the butyric acid separated by distillation. 

A combination with distillation is illustrated by the purification of glycerine. Ordinarily, it is difficult to decolorize crude glycerine to water-whiteness, but the task is easier after one distillation, and even more so after redistillation. In industrial practice, virgin carbon is applied to the twice-distilled glycerine, and the spent carbon from this stage is added to the crude glycerine to remove foam-formers that hinder distillation. 

Significant amounts of activated carbon are consumed in systems applied for purification of pharmaceuticals. The main application of the carbon here is separation of numerous antibiotics, vitamins, and steroids from fermentation broths by adsorption, usually followed by solvent extraction and distillation. Furthermore, activated carbons are used as purification media for other key phannaceutical chemicals as, for instance glycerin. The pharmaceutical industry often uses activated carbons for water purification process (usually in a combination with other purification technologies like deionization [149]) and for the thorough elimination of potential impurities from intravenous solutions prior to packaging [146]. 

---