ETHANOL AND ALCOHOL

Fermentation

Semi-continuous or continuous fermentation with or without yeast recovery and multi- pressure distillation units facilitate the use of low pressure steam from turbine discharge to save energy.

The most suitable and efficient fermentation process is selected in every scenario, with or without yeast recovery. Where stillage recirculation is deemed to be important to reduce the volume of the effluent. Recirculation is used only to the extent that it does not compromise the yeast reproduction rate, duration of the fermentation and fermentation efficiency.

The fermentation units are usually provided with closed fermenters to retrieve the carbon dioxide and wash it in a scrubber to recover the alcohol vapours, before the CO2 is recovered concentration incineration boiler potash recovery for use as fertilizer biological digestion aerobic treatment steam for turbine/process biogas to the boiler process water discharge and sent to drying and compressing station.