Glycerin (Glycerol) is a clear, odorless, viscous liquid with a naturally sweet taste. It is derived from both natural and petrochemical feedstocks. Glycerin occurs in combined form (triglycerides) in animal fats and vegetable oils and is obtained from these fats and oils during transesterification, such as in biodiesel production.
Glycerin currently has over 1500 known uses in many different industries ranging from foods, pharmaceuticals, and cosmetics (USP grade glycerin) to paints, coatings and other industrial types of applications (technical grade glycerin). It continues to be one of the most versatile and valuable byproducts created during biodiesel production.
Glycerin naturally occurs during the biodiesel production process and is specifically produced in the transesterification process. The glycerin produced at this stage is crude glycerin and is about 80% pure still containing contaminants like soap, methanol and water. In order to turn this crude glycerin into a usable state for existing or emerging uses, a purification process must take place. During this refinement process residual organic matter, water, salt, methanol, and odors are removed.
There are many different types of glycerin grades ranging from crude glycerin to refined glycerin (pharmaceutical grade).
Stage 1: Crude Glycerin
Stage 2 : Glycerin
Stage 3 : Glycerin
Stage 4 : Tech Grade Glycerin
The increase in biodiesel production over the past ten years has resulted in substantial increases in glycerin production throughout the world. Because of the large supply of crude glycerin in particular, biodiesel production facilities are looking for alternative ways to purify this glycerin to maximize their profits.
SRS International Corporation has designed a high-purity glycerin purification system giving biodiesel plants the ability to create additional profits through purification of their crude glycerin. Glycerin's value is based on its purity range so the purer the glycerin, the higher the market value. SRS International's system can produce high-purity glycerin in high yield, while maximizing energy efficiency. The system can take crude glycerin with an approximate purity rating of 80% to a technical grade glycerin of >97%.