Patent ID: 8187849
Filing Date: 2012-05-29
Classification: A01N,C12N,C12P,Y02E

Abstract:
1. A method of processing lignocellulosic biomass comprising washing the fiber fraction of a pretreated lignocellulosic feedstock with a pre-defined quantity of water that provides a definite water/biomass ratio whereby optimized levels of fermentation inhibitors are obtained; incorporating the washed fiber fraction or an enzymatic hydrolysate of the washed fiber fraction within a non-sterile yeast fermentation mixture, wherein the yeast fermentation mixture is optionally supplemented with additional water content and/or other chemicals or additives; wherein when the non-sterile fermentation mixture is fermented, lactate yield in the fermentation mixture is lower than about 4 g/kg and ethanol yield is higher than about 75% theoretical yield, wherein the feedstock was pretreated by steam or dilute acid, wherein the pre-defined quantity of water provides a water/biomass ratio of between about 4:1 and about 8:1, and wherein water/biomass ratio refers to the ratio between the initial non-water content of a lignocellulosic biomass prior to pretreatment and the total amount of water to which this material is exposed during and after pretreatment, including water present in the biomass as it is pretreated and water introduced during pretreatment and post pretreatment processing.