Similarities and differences in pretreating woody biomass by steam explosion, wet oxidation, autohydrolysis, and rapid steam hydrolysis/continuous extraction
Steam hydrolysis processes are excellent methods for pretreating and fractionating cellulose from the other major wood components. In this study a comparison was made between four pretreatment processes: steam explosion; wet oxidation; autohydrolysis; and a new process based on rapid steam hydrolysis/continuous extraction. The biomass feedstock used was a low-cost woody substrate consisting of mixed southern hardwoods obtained by total tree chipping. The four pretreatments all employ steam or water and heat; however, there are fundamental differences between each process. The initial reaction involves a mild acid-catalyzed hydrolysis reaction of both the glycosidic bonds of the hemicelluloses and the ..cap alpha..-ether linkage in lignin. Even though the initial reactions for the four processes are similar, the final products are quite different due to the variety of secondary reactions which occur. All four pretreatments dramatically increased the enzymatic hydrolysis rates. However, only the wet oxidation pretreatment increased the acid hydrolysis rate. The hemicelluloses were depolymerized by autohydrolysis, wet oxidation, and steam explosion. The Rapid Steam Hydrolysis/Continuous Extraction process also depolymerized the hemicelluloses but minimized further degradation of the polysaccharides. The lignin was depolymerized by all pretreatments but apparently recondensed at the higher autohydrolysis temperatures. The solid residue remaining after a 260/sup 0/C Rapid Steam Hydrolysis pretreatment had an enriched cellulose content of about 70%.
- Research Organization:
- Mississippi State Univ., Mississippi State (USA). Mississippi Forest Products Utilization Lab.
- OSTI ID:
- 5192616
- Report Number(s):
- CONF-840111-4; ON: DE84900774
- Resource Relation:
- Conference: 8. annual symposium on energy from biomass and wastes, Lake Buena Vista, FL, USA, 30 Jan 1984
- Country of Publication:
- United States
- Language:
- English
Similar Records
Rapid steam hydrolysis/extraction of mixed hardwoods as a biomass pretreatment
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Related Subjects
WOOD
HEAT TREATMENTS
HYDROLYSIS
ACID HYDROLYSIS
CELLULOSE
ENZYMATIC HYDROLYSIS
EXPERIMENTAL DATA
LIGNIN
OPTIMIZATION
OXIDATION
STEAM
CARBOHYDRATES
CHEMICAL REACTIONS
DATA
DECOMPOSITION
INFORMATION
LYSIS
NUMERICAL DATA
ORGANIC COMPOUNDS
POLYSACCHARIDES
SACCHARIDES
SOLVOLYSIS
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