Glycerin in 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).

Other Names for Glycerin

• Glycerol
• Glycerine
• Propane-1,2,3-triol
• 1,2,3-Propanetriol
• 1,2,3-Trihydroxypropane
• Glyceritol
• Glycyl alcohol

Stages of Glycerin Purification

1. 1st Stage — Initial removal of methanol, water, and basic impurities from crude glycerin
2. 2nd Stage — Further purification to reduce salts, soaps, and organic matter
3. 3rd Stage — Advanced refining to achieve technical-grade purity levels
4. Stage 4: Technical Grade Glycerin — Final polishing for high-purity applications

Why Purify 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.