Distillers Grains

ST Equipment & Technology (STET) water-free separation technology group recently completed pilot scale protein enrichment testing on dry distillers grains with solubles (DDGS), resulting in an +15% increase in absolute protein content of the distillers grain by separation of protein and fiber. This process offers ethanol producers, or feed ingredient users, a revolutionary method of generating a 50% protein DDGS co-product. The premium high protein product can be used in monogastric feed applications at high substitution ratios, and therefore can be sold at a premium.

The operating principle of the STET separator is electrostatic separation. Electrostatics has a large number of real-world, industrial applications. Perhaps the most relatable example of electrostatic phenomena is the effect of rubbing a balloon on a person’s hair. As the balloon, made of rubber, comes into contact with human hair, the rubber balloon removes electrons from the hair. The reason for this is due to the high electronegativity (ie – affinity for electrons) of rubber. The result is the balloon is left with a net negative charge, due to extra electrons, and your hair has a positive charge. Of course, like charges repel each other, so your hair stands up on end to maximize the distance between other, positively charged, strands of hair. In the case of DDGS, protein and fiber acquire opposite electrical charge upon contact with each other – allowing them to be separated from each other in the high strength electric field of the STET separator.