Forced recirculation evaporator installed in the Biochemical Pilot Plant at NREL. This unit can be used to concentrate dilute sugar streams or remove volatile compounds.
Here you will find frequently asked questions (FAQs) on biochemical conversion.
QIs it possible to ferment both glucose and xylose derived from biomass using a glucose-xylose fermenting microorganism in the same fermentation tank?
AMany metabolically engineered microorganisms are able to ferment both xylose and glucose in the same tank, which may provide capital savings. Although, the rate of xylose consumption can be slower than glucose consumption.
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Last Reviewed: October 18, 2007
QI was hoping I could conduct an experiment with the bacterium Zymomonas mobilis, however, I have been unable to obtain much information, much less a culture of this bacterium. Could you help me obtain information on this bacterium?
AThe NREL strain of Zymomonas mobilis is both recombinant and patented. The former means that it can only be used in facilities certified for using genetically modified organisms. The latter means that formal licensing agreements need to be made before it can be made available. You could use native microorganisms for separate fermentation of xylose and glucose, respectively. You would still need to break hemicellulose (or xylan) down to xylose and cellulose to glucose.
Last Reviewed: October 18, 2007
QWhat is the difference between ethanol from crops like corn and from cellulosic biomass?
AGrain crops such as corn yield starch or sugar, which can be readily fermented to ethanol. There is already a large, thriving, corn-to-ethanol industry in this country, and a substantial portion of the dry mill ethanol plants are owned by farmer cooperatives. Wet mill plants tend to be much larger and owned by large companies. Dry mill plants produce ethanol and animal feed (distillers dried grains).
Cellulosic biomass includes crop residues such as corn stover, as well as wood residues and wood and herbaceous energy crops, like yellow poplar and switchgrass respecively, which consists primarily of cellulose, hemicellulose, and lignin. The first two can be broken down into their component sugars for subsequent fermentation, but that breakdown (hydrolysis) is a complex and challenging task.
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Last Reviewed: October 19, 2007
QIs ethanol being commercially produced from cellulose and hemicellulose?
AEthanol is not yet being commercially produced from cellulose and hemicellulose, which are the fibrous sugar polymers that make up the bulk of plant material. However, several companies are moving toward commercial production. The Department of Energy (DOE) recently granted six awards for private companies to cost share demonstration cellulosic ethanol production facilities.
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Last Reviewed: October 19, 2007
QWhat is the general technology for producing ethanol from cellulosic biomass?
APlease see the Web page below.
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Last Reviewed: October 19, 2007
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