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
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.