The ‘High Speed / Low Effluent‘ (HS/LE) fermentation process allows for the production of high percentage ethanol beers (10 – 15%) to reach completion ten times faster (4 – 8 hours) than in standard fermentations and allows for the recovery & harvesting of yeast cell mass.

Background: The rate & efficiencies associated with a fermentation is a function of the 1) sugar loading level, 2) organism loading levels, & 3) product inhibition. Standard commercial ethanol fermentation’s are complete after 40 – 80 hours at yeast cell mass loading levels between .01 – .05 g yeast /kg sugar.

Technology Description: The HS/LE fermentation utilizes a patented super floculent, non-GMO, yeast strain (BPSC-15) that allows very high organism loading levels to be reached in the reactor, .1 – .2 kg yeast / kg sugar. The direct relationship between cell mass and fermentation rates allow the speed of the fermentation to be controlled by the periodic harvesting of yeast cell mass. The HS/LE can be designed for batch, continuous batch, consecutive series, or continuous fermentation systems.

Applications: The HS/LE fermentation was designed and developed for the production of industrial ethanol production from cane sugar, molasses, sweet sorghum syrup, corn, and biomass feedstocks. In addition, the HS/LE fermentation process has applications and value in the production of beer, wine, liquors, as well the production of probiotic single cell protein.

HS/LE Advantages:

• Increased Fermentation Speed, Rate, & Efficiencies,
• Reduced Fermentor Size / Volume Requirements,
• Production, Recovery, & Sale of Single Cell Protein,
• Allows Higher Levels of Back-Set & Water Recycling,
• Decreased Probability of Fermentation Infection Rates,
• Variety of Reactor Designs & Operation Configurations,
• Rate of Fermentation a Controllable Process Variable,
• No Need to Purchase Any Dry Yeast for Propagation,

R&D Background: The HS/LE fermentation process has been developed and improved over the last 10 years by BPI, successfully being demonstrated on the laboratory & pilot scales on sugar mashes from sugar cane, molasses, syrups, waste sugar streams, corn, biomass, and sweet sorghum syrup. The HS/LE process and organism was patented by BPI in 2006.

Technology Maturity: Commercial, a commercial demonstration of the HS/LE process was funded by the Department of Energy and conducted at a fuel ethanol production facility from 2005 – 2006. Results, showed that the HS/LE process and organisms performed as well, or better, as in laboratory and pilot scale trials. A HS/LE reactor was run continuously over several years with no degeneration of cells, loss in efficiency, or reactor infection.