A 120-million-gallon-per-year ethanol producer installed Trucent’s COSS system in early 2013. The fully automated COSS modules had performed well, operating at 98% uptime efficiency with the help of Trucent’s Technology Service Program.
Distillers corn oil (DCO) extraction rates were as high as .75 lbs. per bushel since installing the COSS system, but chemical separation additive dosage rates were 300-400 ppm, as pressure to generate greater revenues from coproducts added to the need for improved DCO extraction rates.
Since the initial COSS installation, the plant was aggressive in the expansion of its production capacity, which increased their thin stillage and evaporator flows in the back end. With increased rates, the COSS system continued to provide high removal rates of DCO — higher than the original specification. But as the flows to the COSS modules neared capacity and efficiencies and yields were of concern, it became clear that the producer would need to reevaluate their DCO extraction processes in order to meet future demands.
To help the plant determine the best method for achieving higher yields, Trucent ran tests and confirmed that exposing the stillage to high separation forces (8,000Gs) for an extended time (G-seconds) would result in a gain of 15-20% DCO yields. Within weeks, the third COSS installation and integration was compatible and producing 24% more DCO (limited by feed fat feed tag requirements). In addition, a 70% reduction in chemical usage was achieved, and the producer was realizing an annual savings of $300K.
The projected payback on the third COSS module was less than nine months.