title: Critical conditions for improved fermentability during overliming of acid hydrolysates from spruce.
abstract: 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.
authors.affiliation: Biochemistry, Division for Chemistry, Karlstad University, SE-651 88 Karlstad, Sweden.
authors.forename: Ilona Sárvári
authors.initials: IS
authors.lastname: Horváth
authors.forename: Anders
authors.initials: A
authors.lastname: Sjöde
authors.forename: Björn
authors.initials: B
authors.lastname: Alriksson
authors.forename: Leif J
authors.initials: LJ
authors.lastname: Jönsson
authors.forename: Nils-Olof
authors.initials: NO
authors.lastname: Nilvebrant
mesh_terms: 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
chemical_list: D017610:Calcium Compounds; D003470:Culture Media; D010087:Oxides; D013464:Sulfuric Acids; C036909:lignocellulose; D000431:Ethanol; D002482:Cellulose; D008031:Lignin; C016538:lime; C033158:sulfuric acid