Critical conditions for improved fermentability during overliming of acid hydrolysates from spruce.
Bioethanol can be produced from wood via acid hydrolysis, but detoxification is needed to achieve good fermentability. Overliming was investigated in a factorial designed experiment, in which pH and temperature were varied. Degradation of inhibitory furan aldehydes was more extensive compared to monosaccharides. Too harsh conditions led to massive degradation of sugars and formation of inhibiting acids and phenols. The ethanol productivity and yield after optimal overliming reached levels exceeding reference fermentations of pure glucose. A novel metric, the balanced ethanol yield, which takes both ethanol production and losses of fermentable sugars into account, was introduced and showed the optimal conditions within the investigated range. The findings allow process technical and economical considerations to govern the choice of conditions for overliming.
Horváth
Ilona Sárvári
IS
Biochemistry, Division for Chemistry, Karlstad University, SE-651 88 Karlstad, Sweden.
Sjöde
Anders
A
Alriksson
Björn
B
Jönsson
Leif J
LJ
Nilvebrant
Nils-Olof
NO
D019149:Bioreactors / Q000382:microbiology; D017610:Calcium Compounds / Q000737:chemistry*; D018929:Cell Culture Techniques / Q000379:methods*; D002482:Cellulose / Q000737:chemistry / Q000378:metabolism*; D020650:Combinatorial Chemistry Techniques / Q000379:methods; D003198:Computer Simulation; D003470:Culture Media / Q000737:chemistry* / Q000378:metabolism; D000431:Ethanol / Q000737:chemistry / Q000378:metabolism*; D005285:Fermentation / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry / Q000378:metabolism*; D008954:Models, Biological; D010087:Oxides / Q000737:chemistry*; D028222:Picea / Q000737:chemistry / Q000382:microbiology*; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D013464:Sulfuric Acids / Q000737:chemistry; D013696:Temperature
D017610:Calcium Compounds; D003470:Culture Media; D010087:Oxides; D013464:Sulfuric Acids; C036909:lignocellulose; D000431:Ethanol; D002482:Cellulose; D008031:Lignin; C016538:lime; C033158:sulfuric acid