Crude glycerin (also spelled glycerine or glycerol) is a by-product formed during the production of biodiesel, soap, and fatty acid processing. It is a thick, syrupy liquid with a pale yellow to brown color and has a lower purity compared to refined glycerin.
Composition:
Crude glycerin typically contains:
Glycerol (40â??80%) â?? the main component, though at a lower concentration than in refined glycerin
Water (up to 20%)
Methanol (if from biodiesel)
Soap, salts, free fatty acids, and traces of catalysts (e.g., sodium or potassium hydroxide)
Other organic matter or impurities depending on the feedstock and process
Uses of Crude Glycerin:
Feedstock for Refining.
Crude glycerin is often refined and purified to produce pharmaceutical- or food-grade glycerin, which is used in cosmetics, foods, and medicines.
Animal Feed (after purification).
Can be blended into livestock feed as an energy source, but only after removal of toxic methanol residues.
Biogas Production.
Used as a co-substrate in anaerobic digesters, boosting methane production in biogas plants.
Industrial Applications.
Used in the manufacturing of paints, resins, antifreeze, adhesives, and plasticizers.
Combustion and Fuel.
Sometimes used as a low-grade fuel or fuel additive in industrial burners and boilers.
Chemical Intermediate.
Serves as a base chemical for producing propylene glycol, epichlorohydrin, and other derivatives.
