Organosolv pretreatment for enzymatic hydrolysis of poplars: I. enzyme hydrolysis of cellulosic residues
Aspen (Populus tremuloides) and black cottonwood (Populus trichocarpa) organosolv pulps produced in a wide range of solvent composition (between 30 and 70% by volume of methanol) and catalysts (H/sub 2/SO/sub 4/ and H/sub 3/PO/sub 4/) such that the cooking liquor pH less than or equal to 3 are easily digested by enzymes. The total yields of hydrolysis residues (pulps) are in the 40-60% range; the acid-catalyzed delignification followed by enzyme hydrolysis can generate 70-88% of the original six-carbon sugars contained in the wood. Glucomannan and arabinogalactan are dissolved in to the pulping liquor in the pH range of 2-4.5. Lower pH (less than or equal to 3) leads to additional solubilization of six-carbon sugars. These sugars may be fermented directly. From the insoluble hydrolysis residues, 36-41% conversions of wood into fermentable sugars were obtained after enzyme hydrolysis; the starting feedstocks contain 50.8 and 46.6% hexosans, respectively, for aspen and black cottonwood. The kinetics of enzymatic hydrolysis of cellulose can be formally treated as two simultaneous pseudo-first-order reactions in which fast and slow hydrolysis of cellulose occur. Correlations between the glucan digestibility and the effect of the pretreatment have been made. The higher residual xylan content reduces the amount of the rapidly hydrolyzable glucan fraction and lowers the glucan digestibility. The proposed simple kinetic treatment is very helpful in assessing the effect of the pretreatment on pulp enzyme hydrolyzability.
- Research Organization:
- Solar Energy Research Institute, Golden, CA (USA)
- OSTI ID:
- 6929947
- Journal Information:
- Biotechnol. Bioeng.; (United States), Vol. 31:7
- Country of Publication:
- United States
- Language:
- English
Similar Records
Consolidated bioprocessing of Populus using Clostridium (Ruminiclostridium) thermocellum: a case study on the impact of lignin composition and structure
Development of a geothermally assisted process for the production of liquid fuels and chemicals from pinewood. Executive summary of Final report
Related Subjects
CELLULOSE
ENZYMATIC HYDROLYSIS
POPLARS
RESOURCE POTENTIAL
BIOCHEMICAL REACTION KINETICS
BIOSYNTHESIS
SYNTHETIC FUELS
CARBOHYDRATES
CHEMICAL REACTIONS
DECOMPOSITION
FUELS
HYDROLYSIS
KINETICS
LYSIS
ORGANIC COMPOUNDS
PLANTS
POLYSACCHARIDES
REACTION KINETICS
SACCHARIDES
SOLVOLYSIS
SYNTHESIS
TREES
090222* - Alcohol Fuels- Preparation from Wastes or Biomass- (1976-1989)
140504 - Solar Energy Conversion- Biomass Production & Conversion- (-1989)