Ethanol volatility in fermentation systems. Salt and metabolite effects

Abstract

The effect of dissolved species on the relative volatility of ethanol in fermentation systems is evaluated. New data are presented showing that the enhancement in volatility due to dissolved salts varies with ethanol concentration and is largest for the dilute ethanol concentrations typical in fermentation broths. Dissolved sugars and metabolites also affect relative volatility. The most commonly applied model of volatility enhancement does not incorporate the effect of ethanol concentration, and published enhancement factors measured at high salt and ethanol concentration are not applicable to the conditions of a fermentation broth.

Monitoring of volatiles in alcoholic fermentations on molasses via a gas membrane sensor

“…With another kind of molasses the factor was 2. It has been already shown that the ethanol volatility is affected by the sugar concentration (Maiorella et al 1984). In molasses many other components cause the volatility to increase: salts, proteins, etc.…”

Bioethanol Production from Indica IR.64 Rice Straw Biomass by Direct Saccharification and Fermentation

“…It has high cellulose and hemicelluloses content that can be readily hydrolysed into fermentable sugars. In terms of chemical composition, the straw predominantly contains cellulose (32-47%) hemicelluloses (19-27%) and lignin (5-24%) [4], [5], [6], [7]. The pentoses are dominant in hemicelluloses, in which xylose is the most important sugar (14.8-20.2%) [5], [8].…”