Crude Glycerin

While pure glycerin is colorless, crude glycerin may feature most different color shades. Mostly it is brownish. The higher salt content overlays the characteristic sweet taste of glycerin. Apart from that, there are no appreciable differences versus pure glycerin in terms of physical and chemical properties.

Crude glycerin is mainly obtained in the production of biodiesel. The glycerin content in palm oil, rapeseed and other vegetable oils amounts to about 10 percent. After processing, the degree of purity is approx. 80 percent. Whether eventually crude or pure glycerin is obtained from this process, depends on to what extent the substance is condensed and thus made purer in the course of further distillation. The glycerin content of pure glycerin can amount to 99.9 percent.

An important field of application for this by-product is the feedstuff industry, where it is used, for instance, as an energy supplier and for improving the optical appearance of feedstuff. In addition, it can increase feed intake and serve for ketosis prophylaxis. However, according to the whitelist, glycerin may only be used for feedstuff if exclusively obtained from vegetable fats and oils.

The industry offers manifold fields of application for crude glycerin as well, for example, in the production of textiles, leather, cellulose, paper, and mass or fine chemicals. For lubricants, grease, and release agents, the degree of purity is equally sufficient as for metal processing oils, polishing agents and wax mixtures. For food production or use in pharmaceutics, however, where a degree of purity of over 99.5 percent is required, the degree of purity of crude glycerin is not sufficient.

In biogas plants, the influx of crude glycerin leads to a significant increase in gas production. After a short adaptation phase, it is quickly processed to methane and carbon dioxide by the microorganisms in the fermenter. Even small quantities are sufficient for controlling gas yield and thus power production.