Because of different production methods, glycerol can be divided into natural glycerol (also called saponified glycerol) with natural oil as raw material and synthetic glycerol with propylene as raw material. Saponified glycerol is of better quality than other glycerols and has a wide range of uses. Its main uses are as follows:
- Refrigerant used as liquid fuel for aircraft and automobiles
- Used as brightener for cellophane and plasticizer for coated paper production in paper industry
- As an important moisturizer for surfactant, toothpaste and cosmetics
- Hygroscopicants for leather, textiles, etc., and moisturizers for tobacco in cigarettes
- food flavors, plasticizer raw materials
- Used in the manufacture of nitroglycerin smokeless powder, nitroglycerin alkyd resin and ester gum, etc.
The specific classification of glycerol is: industrial grade, cosmetic grade, food grade, drug grade (divided into drug supplement and drug owner), four grades.
Industrial grade usually refers to the second-class glycerol in GB13206. 95% pharmaceutical grade glycerol has high requirements for impurities in glycerol. There are limits for diethylene glycol and ethylene glycol, and the production of pharmaceutical grade glycerol requires GMP certificate. Food grade glycerol standard is a little vague at present, usually GB13206.
Crude glycerol generally refers to glycerol with glycerol content less than 93%. It is generally used to refine high purity glycerol such as 95%, 98% and 99.5%.
Refined glycerol is a general term, which can be divided into saponified glycerol, hydrolyzed glycerol and refined glycerol according to their different sources of production. Refined glycerol generally refers to cosmetic grade 99.5% glycerol, which is in line with the USP grade glycerol of the United States Pharmacopoeia.
General glycerol refers to 95-concentration glycerol, which is generally used in industry. It can not be used in cosmetics, pharmaceuticals and food industry. Of course,can also be used as food-grade glycerol, for food industry, or better as drug-grade glycerol, for medicines.