Lignocellulosic ethanol production at high-gravity: challenges and perspectives.
In brewing and ethanol-based biofuel industries, high-gravity fermentation produces 10-15% (v/v) ethanol, resulting in improved overall productivity, reduced capital cost, and reduced energy input compared to processing at normal gravity. High-gravity technology ensures a successful implementation of cellulose to ethanol conversion as a cost-competitive process. Implementation of such technologies is possible if all process steps can be performed at high biomass concentrations. This review focuses on challenges and technological efforts in processing at high-gravity conditions and how these conditions influence the physiology and metabolism of fermenting microorganisms, the action of enzymes, and other process-related factors. Lignocellulosic materials add challenges compared to implemented processes due to high inhibitors content and the physical properties of these materials at high gravity.
Industrial Biotechnology, Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg SE-412 96, Sweden.
Rakesh
R
Koppram
Industrial Biotechnology, Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg SE-412 96, Sweden.
Elia
E
Tomás-Pejó
Industrial Biotechnology, Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg SE-412 96, Sweden.
Charilaos
C
Xiros
Industrial Biotechnology, Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg SE-412 96, Sweden. Electronic address: lisbeth.olsson@chalmers.se.
Lisbeth
L
Olsson
D056804:Biofuels; D001709:Biotechnology; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D006112:Gravitation; D008031:Lignin / Q000378:metabolism*
D056804:Biofuels; C036909:lignocellulose; D000431:Ethanol; D008031:Lignin
high dry matter content; high gravity; high solids content; lignocellulosic ethanol