Continuous process of optimized fermentation for the production of alcohol

摘要

A continuous process of optimized fermentation of sugars for the production of alcohol is disclosed, which comprises the following process steps and operational conditions: (a) continuously feeding a wort with a controlled concentration of sugars in the range of 100 to 160 g/l into one or more fermentation vessels arranged in parallel and containing a culture with a concentation of yeast cells in the range of 1011 to 1012 cells per liter, and completely stirring the fermentation medium; (b) controlling the conditions of the fermentation medium by fixing the temperature in the range of 30 DEG to 39 DEG C. and the pH in the range of 3.2 to 4.5; (c) continuously removing from the fermenter a stream of wine obtained from the wort fermentation so as to keep the retention time in the fermenter fixed in the range of 4 to 9 hours; and (d) separating the stream of wine leaving the fermenter into a substantially yeast-free stream and a yeast-concentrated stream, said yeast-containing stream being recirculated into the fermenter and said substantially yeast-free stream being sent to subsequent processing for the recovery of the alcohol. Before being recirculated into the fermenter, the yeast-concentrated stream can be subjected to an optional treatment with an acid during a short period of time.