Patent ID: 8273559
Filing Date: 2012-09-25
Classification: C07C,C10L,C12N,C12P,Y02E,Y02P

Abstract:
1. A method for obtaining a concentrated alcohol solution from a lignocellulosic feedstock, said method comprising the steps of: (i) producing a fermentable sugar solution comprising ammonium salts or a combination of ammonium salts and ammonia, wherein at least a portion of the fermentable sugar solution arises from hydrolyzing the lignocellulosic feedstock; (ii) fermenting the sugar solution to produce a fermentation broth comprising alcohol and at least about 1 g ammonium ions/kg fermentation broth; (iii) concentrating the alcohol in the fermentation broth by distillation to produce an alcohol-enriched vapour; and (iv) reducing the concentration of ammonia in said alcohol-enriched vapour by acid addition, before or during the distillation and then further concentrating alcohol present in said alcohol-rich vapour by an azeotrope breaking process to obtain the concentrated alcohol solution.