Abstract
Steam refining was investigated as a pretreatment for enzymatic hydrolysis of poplar wood from a short rotation plantation. The experiments were carried out without debarking to use an economically realistic raw material. Steam refining conditions were varied in the range of 3–30 min and 170–220°C, according to a factorial design created with the software JMP from SAS Institute Inc., Cary, NC, USA. Predicted steaming conditions for highest glucose and xylose yields after enzymatic hydrolysis were at 210°C and 15 min. Control tests under the optimized conditions verified the predicted results. Further pretreatments without bark showed that the enzymes were not significantly inhibited by the bark. The yield of glucose and xylose was 61.9% of theoretical for the experiments with the whole raw material, whereas the yield for the experiments without bark was 63.6%. Alkaline extraction of lignin from the fibers before enzymatic hydrolysis resulted in an increase of glucose yields from mild pretreated fibers and a decrease for severe pretreated fibers. The extracted lignin had a high content of xylose of up to 14% after very mild pretreatments. On the other hand, molecular weights of the extracted lignin increased substantially after pretreatments with a severity factor above 4. Hence, alkaline extraction of the lignin seems only attractive in a narrow range of steaming conditions.
©2011 by Walter de Gruyter Berlin Boston
Articles in the same Issue
- Editorial
- EWLP 2010, 16th–19th August 2010, Hamburg, Germany
- Review
- Bio based fuels and fuel additives from lignocellulose feedstock via the production of levulinic acid and furfural
- Original Papers
- Optimization of steam pretreatment conditions for enzymatic hydrolysis of poplar wood
- Fungal pretreatment of pine wood to reduce the emission of volatile organic compounds
- Dilute acid pretreatment of starch-containing rice hulls for ethanol production
- Studies of the chemoenzymatic modification of cellulosic pulps by the laccase-TEMPO system
- Development of an integrated thermal and enzymatic hydrolysis for lignocellulosic biomass in fixed-bed reactors
- A larch based biorefinery: pre-extraction and extract fermentation to lactic acid
- Lignins as agents for bio-protection of wood
- Isolation and characterization of the phenolic fractions of wood pyrolytic oil
- Purification of Eucalyptus globulus water prehydrolyzates using the HiTAC process (high-temperature adsorption on activated charcoal)
- Disintegration and dissolution kinetics of wood chips in ionic liquids
- Ionic liquids as media for biomass processing: opportunities and restrictions
- Autohydrolysis of birch wood
- Solvent extraction as a means of preparing homogeneous lignin fractions
- Conditioning of SO2-ethanol-water spent liquor from spruce for the production of chemicals by ABE fermentation
- Total mass balances of SO2-ethanol-water (SEW) fractionation of forest biomass
- Lignin oxidation mechanisms under oxygen delignification conditions. Part 1. Results from direct analyses
- Lignin oxidation mechanisms under oxygen delignification conditions. Part 2: Advanced methods for the detailed characterization of lignin oxidation mechanisms
- Lignin oxidation mechanisms under oxygen delignification conditions. Part 3. Reaction pathways and modeling
- Simplified determination of total lignin content in kraft lignin samples and black liquors
- Xylan deposition onto eucalypt pulp fibers during oxygen delignification
- Dissolution of dissolving pulp in alkaline solvents after steam explosion pretreatments
- Structure and antioxidant activity of diarylheptanoids extracted from bark of grey alder (Alnus incana) and potential of biorefinery-based bark processing of European trees
- Short Note
- Binding affinities of different metal ions to unbleached hardwood kraft pulp
- Meetings
- Meetings
Articles in the same Issue
- Editorial
- EWLP 2010, 16th–19th August 2010, Hamburg, Germany
- Review
- Bio based fuels and fuel additives from lignocellulose feedstock via the production of levulinic acid and furfural
- Original Papers
- Optimization of steam pretreatment conditions for enzymatic hydrolysis of poplar wood
- Fungal pretreatment of pine wood to reduce the emission of volatile organic compounds
- Dilute acid pretreatment of starch-containing rice hulls for ethanol production
- Studies of the chemoenzymatic modification of cellulosic pulps by the laccase-TEMPO system
- Development of an integrated thermal and enzymatic hydrolysis for lignocellulosic biomass in fixed-bed reactors
- A larch based biorefinery: pre-extraction and extract fermentation to lactic acid
- Lignins as agents for bio-protection of wood
- Isolation and characterization of the phenolic fractions of wood pyrolytic oil
- Purification of Eucalyptus globulus water prehydrolyzates using the HiTAC process (high-temperature adsorption on activated charcoal)
- Disintegration and dissolution kinetics of wood chips in ionic liquids
- Ionic liquids as media for biomass processing: opportunities and restrictions
- Autohydrolysis of birch wood
- Solvent extraction as a means of preparing homogeneous lignin fractions
- Conditioning of SO2-ethanol-water spent liquor from spruce for the production of chemicals by ABE fermentation
- Total mass balances of SO2-ethanol-water (SEW) fractionation of forest biomass
- Lignin oxidation mechanisms under oxygen delignification conditions. Part 1. Results from direct analyses
- Lignin oxidation mechanisms under oxygen delignification conditions. Part 2: Advanced methods for the detailed characterization of lignin oxidation mechanisms
- Lignin oxidation mechanisms under oxygen delignification conditions. Part 3. Reaction pathways and modeling
- Simplified determination of total lignin content in kraft lignin samples and black liquors
- Xylan deposition onto eucalypt pulp fibers during oxygen delignification
- Dissolution of dissolving pulp in alkaline solvents after steam explosion pretreatments
- Structure and antioxidant activity of diarylheptanoids extracted from bark of grey alder (Alnus incana) and potential of biorefinery-based bark processing of European trees
- Short Note
- Binding affinities of different metal ions to unbleached hardwood kraft pulp
- Meetings
- Meetings