|
Madtowntripper
Sun-Beams out of Cucumbers



Registered: 03/06/03
Posts: 21,287
Loc: The Ocean of Notions
Last seen: 5 months, 23 days
|
Practical Hydrogen?
#7628266 - 11/12/07 10:29 PM (16 years, 2 months ago) |
|
|
http://news.yahoo.com/s/afp/ussciencefuel
Quote:
CHICAGO (AFP) - US researchers have developed a method of producing hydrogen gas from biodegradable organic material, potentially providing an abundant source of this clean-burning fuel, according to a study released Monday.
The technology offers a way to cheaply and efficiently generate hydrogen gas from readily available and renewable biomass such as cellulose or glucose, and could be used for powering vehicles, making fertilizer and treating drinking water.
Numerous public transportation systems are moving toward hydrogen-powered engines as an alternative to gasoline, but most hydrogen today is generated from nonrenewable fossil fuels such as natural gas.
The method used by engineers at Pennsylvania State University however combines electron-generating bacteria and a small electrical charge in a microbial fuel cell to produce hydrogen gas.
Microbial fuel cells work through the action of bacteria which can pass electrons to an anode. The electrons flow from the anode through a wire to the cathode producing an electric current. In the process, the bacteria consume organic matter in the biomass material.
An external jolt of electricity helps generate hydrogen gas at the cathode.
In the past, the process, which is known as electrohydrogenesis, has had poor efficiency rates and low hydrogen yields.
But the researchers at Pennsylvania State University were able to get around these problems by chemically modifying elements of the reactor.
In laboratory experiments, their reactor generated hydrogen gas at nearly 99 percent of the theoretical maximum yield using aetic acid, a common dead-end product of glucose fermentation.
"This process produces 288 percent more energy in hydrogen than the electrical energy that is added in the process," said Bruce Logan, a professor of environmental engineering at Penn State.
The technology is economically viable now, which gives hydrogen an edge over another alternative biofuel which is grabbing more headlines, Logan said.
"The energy focus is currently on ethanol as a fuel, but economical ethanol from cellulose is 10 years down the road," said Logan.
"First you need to break cellulose down to sugars and then bacteria can convert them to ethanol."
One of the immediate applications for this technology is to supply the hydrogen that is used in fuel cell cars to generate the electricity that drives the motor, but it could also can be used to convert wood chips into hydrogen to be used as fertilizer.
The study appears in the Proceedings of the National Academy of Sciences.
-------------------- After one comes, through contact with it's administrators, no longer to cherish greatly the law as a remedy in abuses, then the bottle becomes a sovereign means of direct action. If you cannot throw it at least you can always drink out of it. - Ernest Hemingway If it is life that you feel you are missing I can tell you where to find it. In the law courts, in business, in government. There is nothing occurring in the streets. Nothing but a dumbshow composed of the helpless and the impotent. -Cormac MacCarthy He who learns must suffer. And even in our sleep pain that cannot forget falls drop by drop upon the heart, and in our own despair, against our will, comes wisdom to us by the awful grace of God. - Aeschylus
Edited by Madtowntripper (11/12/07 10:30 PM)
|
Seuss
Error: divide byzero



Registered: 04/27/01
Posts: 23,480
Loc: Caribbean
Last seen: 2 months, 20 days
|
|
Even if we can't use the hydrogen, it is better to see the trash decompose into hydrogen rather than methane.
-------------------- Just another spore in the wind.
|
Madtowntripper
Sun-Beams out of Cucumbers



Registered: 03/06/03
Posts: 21,287
Loc: The Ocean of Notions
Last seen: 5 months, 23 days
|
Re: Practical Hydrogen? [Re: Seuss]
#7629410 - 11/13/07 08:56 AM (16 years, 2 months ago) |
|
|
I am almost completely ignorant about the science behind the production of hydrogen as a fuel.
Quote:
"This process produces 288 percent more energy in hydrogen than the electrical energy that is added in the process," said Bruce Logan, a professor of environmental engineering at Penn State.
Does this sound like a reasonable yield? One that could actually be used in production?
-------------------- After one comes, through contact with it's administrators, no longer to cherish greatly the law as a remedy in abuses, then the bottle becomes a sovereign means of direct action. If you cannot throw it at least you can always drink out of it. - Ernest Hemingway If it is life that you feel you are missing I can tell you where to find it. In the law courts, in business, in government. There is nothing occurring in the streets. Nothing but a dumbshow composed of the helpless and the impotent. -Cormac MacCarthy He who learns must suffer. And even in our sleep pain that cannot forget falls drop by drop upon the heart, and in our own despair, against our will, comes wisdom to us by the awful grace of God. - Aeschylus
|
Seuss
Error: divide byzero



Registered: 04/27/01
Posts: 23,480
Loc: Caribbean
Last seen: 2 months, 20 days
|
|
> Does this sound like a reasonable yield?
No idea. However, I suspect that they are neglecting to calculate in the costs associated with storing hydrogen gas.
-------------------- Just another spore in the wind.
|
Visionary Tools



Registered: 06/23/07
Posts: 7,953
Last seen: 1 year, 7 months
|
Re: Practical Hydrogen? [Re: Seuss]
#7629770 - 11/13/07 10:50 AM (16 years, 2 months ago) |
|
|
There's already a cheap and efficient way of getting hydrogen: Electrolysis of water. However, compressing and shipping the fuel is where the efficiency is lost, but for vehicles you can't have those plugged into the national grid.
--------------------
|
demiu5
humans, lol


Registered: 08/18/05
Posts: 43,948
Loc: the popcorn stadium
|
Re: Practical Hydrogen? [Re: Seuss]
#7629823 - 11/13/07 11:01 AM (16 years, 2 months ago) |
|
|
Quote:
Seuss said: Even if we can't use the hydrogen, it is better to see the trash decompose into hydrogen rather than methane.
is the methane produced from trash not usable like some of the farms that have started using their manures/residues in large covered containers to collect methane for energy?
-------------------- channel your inner Larry David
|
Visionary Tools



Registered: 06/23/07
Posts: 7,953
Last seen: 1 year, 7 months
|
Re: Practical Hydrogen? [Re: demiu5]
#7629952 - 11/13/07 11:23 AM (16 years, 2 months ago) |
|
|
It's going to take energy to separate the carbon out of methane. Which means carbon dioxide. Burning methane for energy is fine in my book, it's pollutants are water and carbon dioxide.
--------------------
|
johnm214



Registered: 05/31/07
Posts: 17,582
Loc: Americas
|
|
Quote:
Visionary Tools said: There's already a cheap and efficient way of getting hydrogen: Electrolysis of water. However, compressing and shipping the fuel is where the efficiency is lost, but for vehicles you can't have those plugged into the national grid.
That's interesting, I always thought the problem was that you'll never get close to 100% conversion of energy into the hydrogen, so you'll always lose since most schemes simply burn the hydrogen again (reversing the process).
What I think would be interesting is couping the process to nuclear power. If you power hydrogen production with nuclear reactors, I would suspect you could have relativly cheap power... this would in turn convert the nuclear power into a form able to be stored for use in vehicles.
Higher efficiency batteries would of course negate any benifit though
And in the US nobody will allow new nuclear plants anyways...
|
Seuss
Error: divide byzero



Registered: 04/27/01
Posts: 23,480
Loc: Caribbean
Last seen: 2 months, 20 days
|
Re: Practical Hydrogen? [Re: johnm214]
#7630484 - 11/13/07 01:14 PM (16 years, 2 months ago) |
|
|
> If you power hydrogen production with nuclear reactors, I would suspect you could have relativly cheap power...
The "cheap nuclear power" claim is false. Nuclear power is expensive, and dirty. To make it appear cheap, the "fact creators" get crafty with the numbers, leaving out the costs of cleaning up past messes, the lifetime of reactors (you mean they don't last forever?), the cost of building new reactors, the costs of fuel processing, the costs of cleaning from fuel processing, the cost of waste storage, etc, etc, etc.
> is the methane produced from trash not usable
I'm sure it is, but I doubt the speed of production is as good. Methane burns into CO2 or CO while hydrogen burns into water. (Water vapor is also a greenhouse gas.)
-------------------- Just another spore in the wind.
|
Silversoul
Rhizome


Registered: 01/01/05
Posts: 23,576
Loc: The Barricades
|
|
I saw something on the Discovery Channel about some guy who found out how to produce hydrogen from some aluminum alloy mixed with water. Considering aluminum is one of the most abundant metals on earth, it seems like it might actually be a viable solution.
--------------------
|
Diploid
Cuban



Registered: 01/09/03
Posts: 19,274
Loc: Rabbit Hole
|
Re: Practical Hydrogen? [Re: Seuss]
#7630937 - 11/13/07 02:42 PM (16 years, 2 months ago) |
|
|
Water vapor is also a greenhouse gas.
Yeah, but the water vapor that would be released even if the entire world converted to chemically burning hydrogen for energy would be insignificant compared to the water vapor ocean evaporation contributes. Boiling an egg puts more water vapor into the atmosphere than a hydrogen car would driving for miles.
The real variable is global temperature. A tiny rise in temperature puts a huge amount of extra ocean evaporation into the atmosphere and releases stored CO2 from the oceans, which triggers a further rise in temperature...
-------------------- Republican Values: 1) You can't get married to your spouse who is the same sex as you. 2) You can't have an abortion no matter how much you don't want a child. 3) You can't have a certain plant in your possession or you'll get locked up with a rapist and a murderer. 4) We need a smaller, less-intrusive government.
|
|