PMID- 11963855
OWN - NLM
STAT- MEDLINE
DCOM- 20020610
LR  - 20190910
IS  - 0273-2289 (Print)
IS  - 0273-2289 (Linking)
VI  - 91-93
DP  - 2001 Spring
TI  - Continuous countercurrent extraction of hemicellulose from pretreated wood 
      residues.
PG  - 253-67
AB  - Two-stage dilute acid pretreatment followed by enzymatic cellulose hydrolysis is 
      an effective method for obtaining high sugar yields from wood residues such as 
      softwood forest thinnings. In the first-stage hydrolysis step, most of the 
      hemicellulose is solubilized using relatively mild conditions. The soluble 
      hemicellulosic sugars are recovered from the hydrolysate slurry by washing with 
      water. The washed solids are then subjected to more severe hydrolysis conditions 
      to hydrolyze approx 50% of the cellulose to glucose. The remaining cellulose can 
      further be hydrolyzed with cellulase enzyme. Our process simulation indicates 
      that the amount of water used in the hemicellulose recovery step has a 
      significant impact on the cost of ethanol production. It is important to keep 
      water usage as low as possible while maintaining relatively high recovery of 
      soluble sugars. To achieve this objective, a prototype pilot-scale continuous 
      countercurrent screw extractor was evaluated for the recovery of hemicellulose 
      from pretreated forest thinnings. Using the 274-cm (9-ft) long extractor, 
      solubles recoveries of 98, 91, and 77% were obtained with liquid-to-insoluble 
      solids (L/IS) ratios of 5.6, 3.4, and 2.1, respectively. An empirical equation 
      was developed to predict the performance of the screw extractor. This equation 
      predicts that soluble sugar recovery above 95% can be obtained with an L/IS ratio 
      as low as 3.0.
FAU - Kim, K H
AU  - Kim KH
AD  - National Renewable Energy Laboratory, Golden, CO 80401-3393, USA.
FAU - Tucker, M P
AU  - Tucker MP
FAU - Keller, F A
AU  - Keller FA
FAU - Aden, A
AU  - Aden A
FAU - Nguyen, Q A
AU  - Nguyen QA
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - United States
TA  - Appl Biochem Biotechnol
JT  - Applied biochemistry and biotechnology
JID - 8208561
RN  - 0 (Carbohydrates)
RN  - 0 (Polysaccharides)
RN  - 0 (Sulfuric Acids)
RN  - 059QF0KO0R (Water)
RN  - 3K9958V90M (Ethanol)
RN  - 8024-50-8 (hemicellulose)
RN  - O40UQP6WCF (sulfuric acid)
SB  - IM
MH  - Biomass
MH  - Carbohydrates/isolation & purification
MH  - Costs and Cost Analysis
MH  - Ethanol/economics/isolation & purification
MH  - Hydrolysis
MH  - Polysaccharides/*isolation & purification
MH  - Solubility
MH  - Sulfuric Acids
MH  - Temperature
MH  - Water
MH  - *Wood
EDAT- 2002/04/20 10:00
MHDA- 2002/06/11 10:01
CRDT- 2002/04/20 10:00
PHST- 2002/04/20 10:00 [pubmed]
PHST- 2002/06/11 10:01 [medline]
PHST- 2002/04/20 10:00 [entrez]
AID - 10.1385/abab:91-93:1-9:253 [doi]
PST - ppublish
SO  - Appl Biochem Biotechnol. 2001 Spring;91-93:253-67. doi: 
      10.1385/abab:91-93:1-9:253.