jimpeel
Well-Known Member
Yeah, that's it. Let's capture CO2 and bury it! Of course, we'll have to create CO2 to do it; but who's watching anyway?
http://www.theglobeandmail.com/servlet/story/LAC.20090117.FUEL17/TPStory/Environment
http://www.theglobeandmail.com/servlet/story/LAC.20090117.FUEL17/TPStory/Environment
CARBON-NEUTRAL FUEL: A NEW APPROACH
KURT KLEINER
January 17, 2009
Lower fuel prices will ease the effects of recession for some, but if it spurs consumption, the result will inevitably be higher carbon-dioxide emissions. In other words, pressure to find a carbon-neutral fuel is greater than ever.
The goal is to find something that won't add greenhouse gases to the atmosphere when it burns. The answer, according to one Canadian researcher, could be a fuel made with carbon taken out of the atmosphere in the first place.
David Keith, the Canada Research Chair in Energy and the Environment and a professor at the University of Calgary, suggests that a clean synthetic gasoline can be made by combining hydrogen and CO{-2} recovered from the air.
Hydrogen alone has already been proposed as a carbon-neutral fuel because it doesn't release carbon when burned. But there are drawbacks. It will probably have to be made from coal or natural gas, in a process that produces leftover carbon. It is notoriously difficult to ship and store, since it tends to leak out of the smallest cracks. And, even if those obstacles were overcome, the problem remains that every gas-powered vehicle now in use would have to be replaced.
Prof. Keith, along with Frank Zeman of Columbia University in New York, proposes a three-step process.
First, produce hydrogen, using coal or natural gas, and bury the leftover carbon dioxide.
Second, capture some of the carbon dioxide that is already present in the atmosphere.
Third, combine the captured CO{-2} with the hydrogen to create a synthetic fuel similar to gasoline. When the fuel is burned, the CO{-2} returns to the air it came from.
"Essentially, we're using the CO{-2} twice," Prof. Keith says.
Before production can begin, however, carbon-capture technology requires further development. Prof. Keith and others have experimented with chemical processes that can pull CO{-2} out of the atmosphere, but a large-scale operation that can capture significant amounts at a reasonable cost does not yet exist.
In the long run, Prof. Keith says, the cost of switching to carbon-neutral hydrocarbons might make more economic sense than switching to a hydrogen or biofuel economy.
"If you think you want to make a transportation system 50 years from now that has lower CO{-2} impacts, one of your choices is still to have hydrocarbon fuels, but to make them some other way."
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1. Coal or natural gas is broken down to produce CO2, which is stored underground, and hydrogen.
2.A carbon-capture plant collects CO2 from the atmosphere
3. The hydrogen and CO2 are combined to produce gasoline-like fuel
4. Cars run on the synthetic fuel. The CO_ they produce is offset by the carbon captured in step 2
NINIAN CARTER/THE GLOBE AND MAIL
SOURCES: UNIVERSITY OF CALGARY; CARNEGIE MELLON UNIVERSITY, PITTSBURG, PA