Via Argonne National Laboratory -
Independent tests conducted by engineers at the U.S. Department of Energy's (DOE) Argonne National Laboratory on the mono-fueled version of the BMW Hydrogen 7 prototype have found that the car's hydrogen-powered engine surpasses the super-ultra low-emission vehicle (SULEV) level, the most stringent emissions performance standard to date.
"The BMW Hydrogen 7's emissions were only a fraction of SULEV level, making it one of the lowest emitting combustion engine vehicles that have been manufactured," says Thomas Wallner, a mechanical engineer who leads Argonne's hydrogen vehicle testing activities.
"Moreover, the car's engine actively cleans the air. Argonne's testing shows that the Hydrogen 7's 12-cylinder engine actually shows emissions levels that, for certain components, are cleaner than the ambient air that comes into the car's engine." It was not an easy task to measure the Hydrogen 7's emissions. "A gross polluter is easy to measure, but the cleaner the car the harder it is to test," says Don Hillebrand, director of Argonne's Center for Transportation Research.
"Most labs test at the SULEV level. Argonne's vehicle testing facilities are unique in that they are able to detect even trace levels of emissions. In this case, it was near-zero emissions."
After an extensive evaluation by BMW, "Argonne's Advanced Powertrain Research Facility was found to be the only public test facility in North America capable of testing hydrogen vehicles at these low emissions levels," says BMW's Wolfgang Thiel, manager, operating support emissions analysis. "Zero is a very small precise number—we are pushing the boundaries of emissions testing."
BMW has put the bi-fueled hydrogen model into limited series production. Although the vehicle is not yet available for sale to the general public, it is being made available to "influential public figures," whose use demonstrate a new era in clean energy, BMW has said. In the meantime, the greatest challenge to widespread use of hydrogen cars is the limited number of hydrogen refueling stations.
Scientists at U.S. Dept. of Energy's Argonne National Laboratory are looking for an alternative to fossil fuels by working to chemically manipulate algae for production of the next generation of renewable fuels—hydrogen gas. "We believe there is a fundamental advantage in looking at the production of hydrogen by photosynthesis as a renewable fuel," senior chemist David Tiede says.
"Right now, ethanol is being produced from corn, but generating ethanol from corn is a thermodynamically much more inefficient process." Some varieties of algae, a kind of unicellular plant, contain an enzyme called hydrogenase that can create small amounts of hydrogen gas.
Tiede said many believe this is used by nature as a way to get rid of excess reducing equivalents that are produced under high light conditions, but there is little benefit to the plant. Tiede and his group are trying to find a way to take the part of the enzyme that creates the gas and introduce it into the photosynthesis process. The result would be a large amount of hydrogen gas, possibly on par with the amount of oxygen created.
"Biology can do it, but it's making it do it at 5-10% yield that's the problem," Tiede says. "What we would like to do is take that catalyst out of hydrogenase and put it into the photosynthetic protein framework. We are fortunate to have Professor Thomas Rauchfuss as a collaborator from the Univ. of Illinois at Champaign-Urbana who is an expert on the synthesis of hydrogenase active site mimics."
Algae has several benefits over corn in fuel production. It can be grown in a closed system almost anywhere, including deserts or even rooftops, and there is no competition for food or fertile soil. Algae is also easier to harvest because it has no roots or fruit and grows dispersed in water. "If you have terrestrial plants like corn, you are restricted to where you could grow them," Tiede says.
"There is a problem now with biofuel crops competing with food crops because they are both using the same space. Algae provide an alternative, which can be grown in a closed photobioreactor analogous to a microbial fermentor that you could move any place." Tiede admitted the research is its beginning phases, but he is confident in his team and their research goals. The next step is to create a way to attach the catalytic enzyme to the molecule.
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