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Title: Alkali-explosion pretreatment of straw and bagasse for enzymic hydrolysis

Abstract

Sugarcane bagasse and wheat straw were subjected to alkali treatment at 200/sup 0/C for 5 minutes and at 3.45 MPa gas pressure (steam and nitrogen), followed by an explosive discharge through a defibrating nozzle, in an attempt to improve the rate and extent of digestibility. The treatment resulted in the solubilization of 40-45% of the components and in the production of a pulp that gave saccharification yields of 80 and 65% in 8 h for bagasse and wheat straw, respectively. By comparison, alkali steaming at 200/sup 0/C (1.72 MPa) for 5 minutes gave saccharification yields of only 58 and 52% in 48 h. The increase in temperature from 140 to 200/sup 0/resulted in a gradual increase in in vitro organic matter digestibility (IVOMD0) for both the substrates. Also, the extent of alkalinity during pretreatment appears to effect the reactivity of the final product towards enzymes. Pretreatment times ranging from 5 to 60 caused a progressive decline in the IVOMD of bagasse and wheat straw by the alkali explosion method and this was accompanied by a progressive decrease in pH values after explosion. In the alkali-steaming method, pretreatment time had no apparent effect with either substrate. An analysis of the alkali-explodedmore » products showed that substantial amounts of hemicellulose and a small proportion of the lignin were solubilized. The percentage crystallinity of the cellulose did not alter in either substrate but there was a substantial reduction in the degree of polymerization. The superiority of the alkali-explosion pretreatment is attributed to the efficacy of fiber separation and disintegration; this increases the surface area and reduces the degree of polymerization. 33 references.« less

Authors:
;
Publication Date:
Research Org.:
Univ. of Melbourne, Victoria, Australia
OSTI Identifier:
5260368
Resource Type:
Journal Article
Journal Name:
Biotechnol. Bioeng.; (United States)
Additional Journal Information:
Journal Volume: 28:4
Country of Publication:
United States
Language:
English
Subject:
09 BIOMASS FUELS; BAGASSE; ALKALINE HYDROLYSIS; ENZYMATIC HYDROLYSIS; STRAW; CHEMICAL REACTION KINETICS; HYDROXIDES; SACCHARIFICATION; STEAM; SUBSTRATES; SUGAR CANE; WHEAT; AGRICULTURAL WASTES; CEREALS; CHEMICAL REACTIONS; DECOMPOSITION; GRASS; HYDROGEN COMPOUNDS; HYDROLYSIS; KINETICS; LYSIS; ORGANIC WASTES; OXYGEN COMPOUNDS; PLANTS; REACTION KINETICS; SOLVOLYSIS; WASTES; 090222* - Alcohol Fuels- Preparation from Wastes or Biomass- (1976-1989); 140504 - Solar Energy Conversion- Biomass Production & Conversion- (-1989)

Citation Formats

Puri, V P, and Pearce, G R. Alkali-explosion pretreatment of straw and bagasse for enzymic hydrolysis. United States: N. p., 1986. Web. doi:10.1002/bit.260280403.
Puri, V P, & Pearce, G R. Alkali-explosion pretreatment of straw and bagasse for enzymic hydrolysis. United States. https://doi.org/10.1002/bit.260280403
Puri, V P, and Pearce, G R. Tue . "Alkali-explosion pretreatment of straw and bagasse for enzymic hydrolysis". United States. https://doi.org/10.1002/bit.260280403.
@article{osti_5260368,
title = {Alkali-explosion pretreatment of straw and bagasse for enzymic hydrolysis},
author = {Puri, V P and Pearce, G R},
abstractNote = {Sugarcane bagasse and wheat straw were subjected to alkali treatment at 200/sup 0/C for 5 minutes and at 3.45 MPa gas pressure (steam and nitrogen), followed by an explosive discharge through a defibrating nozzle, in an attempt to improve the rate and extent of digestibility. The treatment resulted in the solubilization of 40-45% of the components and in the production of a pulp that gave saccharification yields of 80 and 65% in 8 h for bagasse and wheat straw, respectively. By comparison, alkali steaming at 200/sup 0/C (1.72 MPa) for 5 minutes gave saccharification yields of only 58 and 52% in 48 h. The increase in temperature from 140 to 200/sup 0/resulted in a gradual increase in in vitro organic matter digestibility (IVOMD0) for both the substrates. Also, the extent of alkalinity during pretreatment appears to effect the reactivity of the final product towards enzymes. Pretreatment times ranging from 5 to 60 caused a progressive decline in the IVOMD of bagasse and wheat straw by the alkali explosion method and this was accompanied by a progressive decrease in pH values after explosion. In the alkali-steaming method, pretreatment time had no apparent effect with either substrate. An analysis of the alkali-exploded products showed that substantial amounts of hemicellulose and a small proportion of the lignin were solubilized. The percentage crystallinity of the cellulose did not alter in either substrate but there was a substantial reduction in the degree of polymerization. The superiority of the alkali-explosion pretreatment is attributed to the efficacy of fiber separation and disintegration; this increases the surface area and reduces the degree of polymerization. 33 references.},
doi = {10.1002/bit.260280403},
url = {https://www.osti.gov/biblio/5260368}, journal = {Biotechnol. Bioeng.; (United States)},
number = ,
volume = 28:4,
place = {United States},
year = {1986},
month = {4}
}