Method to separate ethanol fermented from sugar derived from a biomass

A method to separate ethanol from a fermentation process contained in a vessel, which comprises:

• providing a fermentation vessel in which ethanol and carbon dioxide are produced by fermentation, and
• providing carbon dioxide, containing ethanol, to said vessel to humidify said ethanol within said vessel by said carbon dioxide, containing ethanol, and
• providing a supply of sugars for fermentation to form ethanol and carbon dioxide, and
• combining said carbon dioxide, produced by fermentation, with the carbon dioxide, containing ethanol, to form ethanol humidified carbon dioxide, and
• separating the resulting humidified carbon dioxide from the fermentation vessel, and
• removing means for condensing ethanol from said humidified carbon dioxide to supply carbon dioxide, containing ethanol, for recycle, and purged carbon dioxide containing ethanol to remove carbon dioxide produced by fermentation, and
• removing fermentation broth from said vessel to maintain vessel level thereby removing ethanol from the humidified carbon dioxide to produce ethanol and carbon dioxide, containing ethanol, for recycle and removing carbon dioxide produced by fermentation and substantially maintaining broth level within the fermentation vessel.