----- Original Message ----- From: "Steve Spence" <[EMAIL PROTECTED]> Newsgroups: sci.energy.hydrogen Sent: Thursday, January 01, 2004 9:00 PM Subject: WISCONSIN TEAM ENGINEERS HYDROGEN FROM BIOMASS
> WISCONSIN TEAM ENGINEERS HYDROGEN FROM BIOMASS > > > > http://www.news.wisc.edu/releases/7766.html > MADISON - In the search for a nonpolluting energy source, hydrogen is often > cited as a potential source of unlimited clean power. But hydrogen is only > as clean as the process used to make it. Currently, most hydrogen is made > from fossil fuels like natural gas using multi-step and high-temperature > processes. > > Now, chemical engineers at the University of Wisconsin-Madison have > developed a new process that produces hydrogen fuel from plants. This source > of hydrogen is non-toxic, non-flammable and can be safely transported in the > form of sugars. > > Writing this week (Aug. 29) in the journal Nature, research scientist Randy > Cortright, graduate student Rupali Davda and professor James Dumesic > describe a process by which glucose, the same energy source used by most > plants and animals, is converted to hydrogen, carbon dioxide, and gaseous > alkanes with hydrogen constituting 50 percent of the products. More refined > molecules such as ethylene glycol and methanol are almost completely > converted to hydrogen and carbon dioxide. > > "The process should be greenhouse-gas neutral," says Cortright. "Carbon > dioxide is produced as a byproduct, but the plant biomass grown for hydrogen > production will fix and store the carbon dioxide released the previous > year." > > Glucose is manufactured in vast quantities -- for example, in the form of > corn syrup -- from corn starch, but can also be made from sugar beets, or > low-cost biomass waste streams like paper mill sludge, cheese whey, corn > stover or wood waste. > > While hydrogen yields are higher for more refined molecules, Dumesic says > glucose derived from waste biomass is likely to be the more practical > candidate for cost effectively generating power. > > "We believe we can make improvements to the catalyst and reactor design that > will increase the amount of hydrogen we get from glucose," says Dumesic. > "The alkane byproduct could be used to power an internal combustion engine > or a solid-oxide fuel cell. Very little additional energy would be required > to drive the process." > > Because the Wisconsin process occurs in a liquid phase at low reaction > temperatures (227 degrees C., 440 degrees F.) the hydrogen is made without > the need to vaporize water. That represents a major energy savings compared > to ethanol production or other conventional methods for producing hydrogen > from fossil fuels based on vapor-phase, steam-reforming processes. > > In addition, the low reaction temperatures result in very low carbon > monoxide (CO) concentrations, making it possible to generate fuel-cell-grade > hydrogen in a single-step process. The lack of CO in the hydrogen fuel > clears a major obstacle to reliable fuel cell operation. CO poisons the > electrode surfaces of low-temperature hydrogen fuel cells. > > At current hydrogen yields, the team estimates the process could cost > effectively generate electrical power. That, according to the Wisconsin > researchers, assumes a low-cost biomass waste stream can be efficiently > processed and fed into the system. > > To be truly useful, the team says several process improvements must first be > made. The platinum-based catalyst that drives the reaction is expensive and > new combinations of catalysts and reactor configurations are needed to > obtain higher hydrogen yields from more concentrated solutions of sugars. > # # # > -- Jim Beal (608) 263-0611, [EMAIL PROTECTED] > -- > > > -- > Steve Spence > Renewable energy and sustainable living > http://www.green-trust.org > Donate $30 or more to Green Trust, and receive > a copy of Joshua Tickell's "From the Fryer to > the Fuel Tank", the premier documentary of > biodiesel and vegetable oil powered diesels. > > Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/index.php?list=biofuel Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] ------------------------ Yahoo! Groups Sponsor ---------------------~--> Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark Printer at MyInks.com. Free s/h on orders $50 or more to the US & Canada. http://www.c1tracking.com/l.asp?cid=5511 http://us.click.yahoo.com/mOAaAA/3exGAA/qnsNAA/FGYolB/TM ---------------------------------------------------------------------~-> Yahoo! Groups Links To visit your group on the web, go to: http://groups.yahoo.com/group/biofuel/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
