Steam-explosion pretreatment of wood: effect of chip size, acid, moisture content and pressure drop

Journal Article · Sun Jun 01 04:00:00 EDT 1986 · Biotechnol. Bioeng.; (United States)

DOI:https://doi.org/10.1002/bit.260280604· OSTI ID:5296580

Brownell, H H; Yu, E K.C.; Saddler, J N

Material balances for pentosan, lignin, and hexosan, during steam-explosion pretreatment of aspenwood, showed almost quantitative recovery of cellulose in the water-insoluble fraction. Dilute acid impregnation resulted in more selective hydrolysis of pentosan relative to undesirable pyrolysis, and gave a more accessible substrate for enzymatic hydrolysis. Thermocouple probes, located inside simulated aspenwood chips heated in 240 degrees C-saturated steam, showed rapid heating of air-dry wood, whereas green or impregnated wood heated slowly. Small chips, 3.2 mm in the fiber direction, whether green or air dry gave approximately equal rates of pentosan destruction and solubilization, and similar yields of glucose and of total reducing sugars on enzmatic hydrolysis with Trichoderma harzianum. Partial pyrolysis, destroying one-third of the pentosan of aspenwood at atmospheric pressure by dry steam at 276 degrees C, gave little increase in yield of reducing sugars on enzymatic hydrolysis. Treatment with saturated steam at 240 degrees C gave essentially the same yields of butanediol and ethanol on fermentation with Klebsiella pneumoniae, whether or not 80% of the steam was bled off before explosion and even if the chips remained intact, showing that explosion was unnecessary. 17 references.

• Research Organization: Forintek Canada Corp., Ottawa
• OSTI ID: 5296580
• Journal Information: Biotechnol. Bioeng.; (United States), Journal Name: Biotechnol. Bioeng.; (United States) Vol. 28:6; ISSN BIBIA
• Country of Publication: United States
• Language: English

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ACID HYDROLYSIS
ALCOHOLS
ALDEHYDES
ASPENS
BACTERIA
BIOSYNTHESIS
CARBOHYDRATES
CELLULOSE
CHEMICAL REACTIONS
DECOMPOSITION
ENZYMATIC HYDROLYSIS
ETHANOL
FLASH HEATING
FUNGI
GLUCOSE
HEAT TREATMENTS
HEATING
HEXOSES
HYDROLYSIS
HYDROXY COMPOUNDS
KLEBSIELLA
LYSIS
MATERIAL BALANCE
MICROORGANISMS
MOISTURE
MONOSACCHARIDES
ORGANIC COMPOUNDS
PLANTS
POLYSACCHARIDES
PYROLYSIS
SACCHARIDES
SOLVOLYSIS
STEAM
SUBSTRATES
SYNTHESIS
THERMOCHEMICAL PROCESSES
TREES
TRICHODERMA
WOOD