Crude glycerin, also known as crude glycerol or raw glycerin, is a co-product of biodiesel production. It is a viscous, colorless, odorless liquid that is obtained during the transesterification process of fats or oils to produce biodiesel. Glycerin is a natural compound found in fats and oils and is typically composed of glycerol molecules.

Crude glycerin contains impurities such as methanol, water, salts, and fatty acids, which are byproducts of the biodiesel production process. While crude glycerin is not suitable for direct use in many applications, it can be refined to produce pure glycerin, which has various commercial and industrial applications.

Some common applications of crude glycerin and refined glycerin include:

1. Pharmaceutical and personal care products: Glycerin is widely used in pharmaceuticals, cosmetics, and personal care products such as moisturizers, lotions, creams, toothpaste, and soaps due to its moisturizing and emollient properties.

2. Food industry: Glycerin is used as a sweetener, humectant, and solvent in food products. It can be found in items like baked goods, candies, confectionery, dairy products, and beverages.

3. Pharmaceutical formulations: Glycerin is used as a solvent and as a component in various pharmaceutical formulations such as cough syrups, lozenges, and suppositories.

4. Tobacco industry: Glycerin is used as a humectant and moistening agent in the production of tobacco products such as cigarettes, cigars, and chewing tobacco.

5. Animal feed: Crude glycerin can be used as an energy source or feed additive in animal feed formulations, particularly for ruminants such as cattle and sheep.

6. Industrial applications: Glycerin is used in various industrial applications such as antifreeze formulations, lubricants, explosives, and as a component in the production of polyols for polyurethane foam.

Overall, crude glycerin and refined glycerin have diverse applications across different industries due to their versatile properties and functionality.