Hemicellulose conversion by anaerobic digestion

Conference · Fri Jan 01 00:00:00 EST 1982

OSTI ID:5450546

Ghosh, S; Henry, M P; Christopher, R W

The digestibility of an aquatic biomass (water hyacinth), a land-based biomass (Coastal Bermuda grass), and a biomass-waste blend (a mixture of hyacinth, grass, MSW, and sludge) under various digestion conditions was studied. Anaerobic digestion of hemicellulose consists of the steps of enzymatic hydrolysis of hemicellulose to glucans, mannans, galactans, xylans, and arabans, and then to simple hexose and pentose sugars; production of C/sub 2/ and higher fatty acids from the simple sugars; conversion of higher fatty acids to acetate; and finally, production of methane and CO/sub 2/ from acetate, and CO/sub 2/ and hydrogen. The conversion of hemicellulose was higher under mesophilic conditions than those of cellulose or protein for all biomass test feeds, probably because the hemicellulose structure was more vulnerable to enzymatic attack than that of the lignocellulosic component. Cellulose conversion efficiencies at the mesophilic and thermophilic temperatures were about the same. However, hemicellulose was converted at a much lower efficiency than cellulose during thermophilic digestion - a situation that was the reverse of that observed at the mesophilic temperature. Cellulose was utilized in preference to hemicellulose during mesophilic digestion of nitrogen-supplemented Bermuda grass. It was speculated that Bermuda grass cellulose was converted at a higher efficiency than hemicellulose in the presence of external nitrogen because the metabolism of the breakdown product (glucose) of cellulose requires the least investment of enzymes and energy.

• Research Organization: Institute of Gas Technology, Chicago, IL (USA); United Gas Pipe Line Co., Houston, TX (USA)
• OSTI ID: 5450546
• Report Number(s): CONF-820202-16; ON: DE82902744
• Resource Relation: Conference: AICHE 1982 national winter meeting, Orlando, FL, USA, 28 Feb 1982
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
GRASS
ANAEROBIC DIGESTION
HEMICELLULOSE
MUNICIPAL WASTES
SEWAGE SLUDGE
WATER HYACINTHS
CARBON DIOXIDE
ENZYMATIC HYDROLYSIS
HYDROGEN
MESOPHILIC CONDITIONS
METABOLISM
METHANE
SACCHARIDES
THERMOPHILIC CONDITIONS
ALKANES
AQUATIC ORGANISMS
BIOCONVERSION
CARBOHYDRATES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
DIGESTION
ELEMENTS
HYDROCARBONS
HYDROLYSIS
LYSIS
MANAGEMENT
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLANTS
POLYSACCHARIDES
PROCESSING
SEWAGE
SLUDGES
SOLVOLYSIS
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
140504* - Solar Energy Conversion- Biomass Production & Conversion- (-1989)
090122 - Hydrocarbon Fuels- Preparation from Wastes or Biomass- (1976-1989)