Tuesday, April 20, 2010
8-16
Evaluation of pretreatment techniques for the production of biogas and bioethanol from cellulosic biomasses
To meet the developing need for bioenergy various feedstocks must be considered for energy production. Certain lignocellulosic feedstocks such as forest and agricultural residues are usually of low cost and don't oppose food production. Such feedstocks are attractive for energy production towards replacing fossil fuels. To produce ethanol and methane from lignocelluloses, pretreatment is needed. In this presentation we test different pretreatment techniques applied to different feedstocks and to both ethanol and biogas production. We show that the yields of methane and ethanol both depend on the pretreatment technique and feedstock.
To study the potential of biogas production from lignocellulosic biomass, four different sample feedstocks
(oat straw, meadow grass, wheat straw and aspen wood) were thermochemically pretreated with different techniques.
The production of methane in the subsequent anaerobic digestion, performed at a fixed temperature, was then monitored up to 55 days.
Both the overall yield of methane and the length of the initial lag phase of the production were dependent on a combination of pretreatment
techniques and feedstock. For some feedstocks, pretreatment seemed to have little or no effect on the yield. Dilute sulfuric acid
showed the shortest initial lag phase on three of the four substrates but also the smallest impact on biogas potential for all substrates.
In an ethanol production experiment, dried oat straw was chopped and subjected to steam explosion
or calcium hydroxide pretreatment, prior to enzymatic hydrolysis at 55 °C for 72 hours. Initial
small scale fermentability tests indicated that it is not necessary to add extra nitrogen
to the hydrolysates, whereas inclusion of the solid portion of the hydrolysate gave substantially
higher ethanol yield than the soluble fraction alone. The total ethanol yields from the thermochemically
and enzymatically pretreated oat straw were measured after anaerobic fermentation of the hydrolysates using Baker's yeast,
Saccharomyces cerevisiae, in one liter fermentors.
To study the potential of biogas production from lignocellulosic biomass, four different sample feedstocks
(oat straw, meadow grass, wheat straw and aspen wood) were thermochemically pretreated with different techniques.
The production of methane in the subsequent anaerobic digestion, performed at a fixed temperature, was then monitored up to 55 days.
Both the overall yield of methane and the length of the initial lag phase of the production were dependent on a combination of pretreatment
techniques and feedstock. For some feedstocks, pretreatment seemed to have little or no effect on the yield. Dilute sulfuric acid
showed the shortest initial lag phase on three of the four substrates but also the smallest impact on biogas potential for all substrates.
In an ethanol production experiment, dried oat straw was chopped and subjected to steam explosion
or calcium hydroxide pretreatment, prior to enzymatic hydrolysis at 55 °C for 72 hours. Initial
small scale fermentability tests indicated that it is not necessary to add extra nitrogen
to the hydrolysates, whereas inclusion of the solid portion of the hydrolysate gave substantially
higher ethanol yield than the soluble fraction alone. The total ethanol yields from the thermochemically
and enzymatically pretreated oat straw were measured after anaerobic fermentation of the hydrolysates using Baker's yeast,
Saccharomyces cerevisiae, in one liter fermentors.
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See more of The 32nd Symposium on Biotechnology for Fuels and Chemicals (April 19-22, 2010)
See more of General Submissions
See more of The 32nd Symposium on Biotechnology for Fuels and Chemicals (April 19-22, 2010)