Details

Title:

Bioconversion of Lignocellulosic Hydrolysates: Strategies to Overcome the Inhibitory Effects at High Gravity Processes

Author(s):

Xiros, C.X., Olsson, L.O.

Document(s):

Abstract:

The main advantage of biomass bioconversion at high gravity (HG, initial dry mater above 12% w/w) or very high gravity (VHG, above 30% w/w) conditions is the generation of high final ethanol concentrations (above 5% v/v), decreasing the cost of the distillation step. The generation of increased amounts of inhibitors during the pretreatment step is one of the challenges that accompany the increase in initial dry mater. Detoxification of the medium, adaptation of the cells prior to fermentation, nutrients supplementations were the strategies used in the present study as tools to unravel the toxicity effects by lignocellulosic hydrolysates. Different methods were evaluated for the bioconversion of softwood dilute acid hydrolysate. A thermotolerant yeast strain, Thermosacc® was used as the fermentative microorganism. The detoxification of pretreated high gravity spruce with reducing agents (Na2S2O4) increased ethanol yield and productivity during simultaneous saccharification and fermentation (SSF) and separate hydrolysis and fermentation (SHF) experiments. The enhancement was explained by the improved viability of the cells during fermentation. The efficiencies of nutrients supplementation and adaptation, as strategies to enhance the ethanol yields, decreased as the fermentation temperature.

Keywords:

bioethanol, lignocellulose, inhibitors, strategy, strategies, high gravity conversion technology

Topic:

R&D on Processes for Solid, Liquid and Gaseous Fuels from Biomass

Subtopic:

Bioethanol production and sugar release from lignocellulosic biomass

Event:

21st European Biomass Conference and Exhibition

Session:

3EO.3.3

Pages:

1432 - 1438

ISBN:

978-88-89407-53-0

Paper DOI:

10.5071/21stEUBCE2013-3EO.3.3

Price:

FREE