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The Physics of the Hydrogen Economy
Spy der Mann writes "A Physics Today article entitled The Hydrogen Economy explores the possibility of using hydrogen as an energy source. The article explores the current methods, limitations, and the need for more research. For those wanting to point out the Hindenburg incident, the article doesn't talk about gaseous hydrogen only, but also about hydrogen fuel cells. My favorite quote: 'The natural world began forming its own hydrogen economy 3 billion years ago, when it developed photosynthesis to convert CO2, water, and sunlight into hydrogen and oxygen'. Interesting read for eco-fans."
This looks like something I read in January's Popular Science last week!
The real problem with the Hindenburg wasn't the Hydrogen inside, it was the flammable skin-coating on the outer covering. The Hydrogen alone wouldn't have reacted so wildly.
Hydrogen is energy storage and transfer medium, not a power source. At least not in what is generally called "hydrogen economy". It takes a lot of energy to make Hydrogen (H2) in large amounts, and only quita s small portion of that "original" power is regained when the Hydrogen is later used as fuel.
Of course fusion power would use Hydrogen as power source, but that's a totally different issue, and it happening is probably much farther in the future than "Hydrogen Economy"...
But I always thought the byproducts of photosynthesis were carbohydrates and oxygen, not oxygen and hydrogen as the article suggests? Hydrogen is used as a source in the photosynthesis process (usually taken from water), not produced as a result.
Your remark number 2 is emphasized in the article, and the article goes over ways to aquire hydrogen through clean renewable methods.
Hydrogen is like a magic genie..
Everyone can agree it is a good thing, but nobody knows how to get it.
Where do we get it? If we use solar panels to create hydrogen, it would be far more efficient to just use the electricity then to convert it to hydrogen. In reality most hydrogen we make comes from reformed gasoline, thermodynamics tells us that wed be better off just burning the gasoline in the first place.
The hydrogen economy is a bush sham.
Everyone in the DOE knows it
Everyone in the DOE who said it, is no longer with the DOE.
I should know, I never could get work as a physicist:-( There are other analyses that say a hydrogen economy is a daydream. you still have to GET the energy from some where If that is to be done without further burning of fossil fuels, we have to commandeer a huge amount of land for solar and wind farms and those are political and financial undertakings that are NOT an easy sell. Especially when the biggest fossil burning country reneges on Kyoto accords and is run by former president and vice president of oil or oil services companies.
SLASHDOT: news for people who can't concentrate on work or have no life at all and got tired of yelling back at the TV.
The article makes no mention of the potential environmental effects of large-scale hydrogen production. To make hydrogen, you could use a nuclear reactor as suggested but that produces nuclear waste. You could invent some kind of biochemical method but that will probably require living cells and large quantities of clean water - which is also needed by growing human populations. The solar method is clean when working but the photochemical cells would probably be quite toxic.
I do not think the "hydrogen economy" will provide limitless clean energy without any environmental costs or risks.
[Sir Garlon] is the marvellest knight that is now living, for he destroyeth many good knights, for he goeth invisible.
You can buy a diesel Civic in other parts of the world. We're screwed in the US though...
"People that quote themselves in their signatures bother me" - athakur999
The article isn't about how wonderful the hydrogen economy will be etc. etc. Nor is it about the Hindenburg. It's about the immense basic science challenges that will likely prevent any commercial viability for decades...
Given that the article was directed at research physicists (readers of Physics Today), the intent was probably to motivate people to look into these challenges as basic science research areas for their labs.
The main reason they think there's any point at all is because of the energy conversion efficiency of fuel cells, and the natural link between fuel cell use and hydrogen. But as the original post implies, one of the best ways to store hydrogen is in the form of hydrocarbons:
Energy: time to change the picture.
Every technology has its unexpected negative consequences.
This is one of the few things I remember from chemistry.. we watched a video where they had various tanks of gases, they put them in a field and shot that them, then tried the same experiment but with a spark generator near-by. Can't remember the exact results except the conclusion that Hydrogen was pretty safe. The Hindenberg was something to do with the skin of the airship.
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Complete bullshit. If you failed chemistry 101, why even comment? (Oh, I forgot, this is slashdot - where everybody dumps his brain-farts)
The oxidation of hydrocarbons does not at all proceed via hydrogen. What's providing the energy is the exceptional stability of water (in case of hydrogen burning) respectively water and carbon dioxide (in case of hydrocarbon burning). Matter of fact, you can also burn coke (cue the jokes, please), which is practically only carbon, without hydrogen. And let me tell you: it gets HOT.
For a green source of energy, what you want to avoid is the carbon. Or at least get your carbon somehow from CO2 in the air.
'scuse me for a moment to interject, but Biodiesel != Greasel...
Biodiesel is refined.
AFAIK the only difference to an engine with biodiesel is that the timing needs to be adjusted differently, other than that most diesel engines are ready to go.
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How does this alleviate global warming? Does biodiesel not release carbon dioxide when it burns?
Of course it does, but its creation consumes as much.
OK Since I'm the one who submitted the article, please allow me to clarify some logical errors in your statements.
,insert the electrodes, add some acid as catalyst, and plug the wires into a battery. Voila! Oxygen in one, hydrogen in the other. Now Try making oil from wood with your chemistry kit.
So, in order to have a large-scale hydrogen "economy", you need an alternate power source to make all that hydrogen in the first place.
News for you. Hydrogen is not "made". It's extracted. OK, putting the word jokes aside, I understand that what you mean is that *PURE* hydrogen is not found *NATURALLY* on Earth.
So we need an ALTERNATIVE power source to obtain it. So what? Electricity is not energy either! It's a bunch of electrons and possitive ions waiting for us to mix them together. We use turbines in dams to produce it. (kynetic energy -> electrical energy). We need engines (kynetic->chemical) to take out the oil from the deposits below Earth.
Didn't you study physics in high school? Just climbing some stairs transforms the kinetic energy you use to move, into "potential energy". And by falling you turn it into kinetic energy, too. And guess what, we're made of protons,electrons and neutrons, and all of these are made of quantums, which are discrete packets of *energy*.
EVERYTHING's energy, dude! So what's the mystery if hydrogen needs some alternate energy to be extracted from water or other compounds? Don't forget your thermodynamics lessons from college. All engines do is transforming one form of energy into another. And since no engine is 100% efficient, then we have what is known as "entropy", which constantly is increased across the universe.
So, what power source can we have to extract pure H2 from other materials? Well, we can have, for example, solar power.
Hydrogen can be built *instantly* with some electrolysis (either chemically or solar powered). I did it myself at home when i was a kid. You put these water-filled tubes in a bucket (upside down)
The H2-generating process is sub-optimal right now (as was the vacuum tube in the 70's to act as a current switch), but technology always improves with time. And don't forget that big companies like Shell are investing millions of dollars into research.
The point with using hydrogen, is that:
a) It's combustible and can produce energy when reacting chemically with other elements/compounds.
b) Unlike fossil fuels, it doesn't require millions of years to be produced/extracted/whatever.
c) It's clean, it doesn't produce CO2 when burned.
Did you RTFA by the way? How do you think fossil fuels are made? Plants transformed H2O + CO2 + SOLAR POWER + nutrients into wood (and O2 as a byproduct). And these with time were transformed into hydrocarbons. Which consist of long hydrogen and carbon chains (not to be confused with carbohydrates - sugars -, which have oxygen in them).
The real energy in hydrocarbons is stored in the chemical bonds between the carbon and hydrogen atoms. By burning them, the combustion process releases these bonds. O2 + (long chains of C + H) ---> H2O + CO2. See? There's the hydrogen, and the C. What we're wanting to do, is get the carbon out of the equation. O2 + 2H2 ---> 2 H2O.
So, is hydrogen economy all that far-fetched? No, it isn't! We've been using hydrogen in our cars for a lot of time. The problem is that we're also using carbon.
Frankly, I'm amazed why your post was moderated as "insightful" (someone MOD it as overrated, please!). More mysterious than the universe is the human ignorance.
P.S. If this post is modded up, please do so as "informative".
Well, fossil fuels are pumped from the ground, burned, and the combustion products go into the atmosphere with no way to to be re-fixxed into the underground petrol, thus producing an open loop (bad) Carbon cycle. The combustion products of plant derived fuels are re-fixxed into succeeding generations of plants thus closing the loop (good) with a zero net gain of Carbon into the atmosphere.
My dad worked in two nuclear power plants and on several naval vessels (some nuclear) as a welder. He says the same thing about looking for steam leaks (with a broomhandle instead of a 2x4), but it's not because the steam will ignite the wood -- it's because those leaks may be thousands of PSI. What you're looking for, is for the end of the broom to suddenly fall off as the steam pressure carves it right in two.
-- Old Man Kensey
Actualy a lot of work is being done on Stirling engines. One thing they would be good at is exhaust gas waste heat reclaimation, where a good amount of a gasoline or Diesel engine's losses occur, hot exhaust. Suck up the waste heat and run a generator with it.
Stirlings would be interesting in private aviation, present engines use leaded gasoline which is getting scarcer and more expensive. Swithching to stirling's would alow the average person to own a plane that not only burned Jet A fuel, but also developed more power with altitude.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Yes, but biodiesel is refined. Your exhaust will not smell like grease. there's been a tonne of info in the past here, and there's a major distinct difference between greasel and biodiesel. Greasel smells like MacDonalds. Biodiesel smells like diesel.
The problem with diesel and biodisel is that it has a particulate exhaust, which is detrimental to the environment. Particulate exhaust is a major contributor to greenhouse gasses. Biodiesel isn't a green solution like Hydrogen.
I don't know if anyone's done the math yet (land needed to provide x amount of fuel), but I've heard it's a pretty limited yield. I don't think there's enough agricultural land to cover a global demand spike for Canola oil.
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One of the leading CEO's of an energy company
was interviewed by Charlie Rose recently. He
stated that the most cost effective source of
hydrogen was to strip it off of natural gas.
I see a really big problem with that solution --
to be truly environmentally friendly, the new
"hydrogen economy" cannot use a carbon-based
source. The resultant byproduct, carbon dioxide,
is also a greenhouse gas. The only way to have
an effective "zero sum" energy solution is a
non-polluting (hydro/wave/solar/geothermal)
source of electrical generation to split water
(H2O) into hydrogen and oxygen gases. Until
such a process becomes economically competitive,
an agricultural based bio-diesel solution is
the better choice.
In fact, its creation consumes *exactly* as much as will be liberated by burning it. The reason that burning oil creates a greenhouse gas issue is that the CO2 that is released from the reaction was sealed away millions of years ago, so the net free gas goes up. With algae, you're releasing CO2 that was just removed from the atmosphere a few weeks/months earlier, so the net free CO2 stays level.
"Because Science" is one step from "Because old book". Try "Because of my experiment testing my falsifiable assertion".
I'm not sure about "heard it first here".
Geothermal power has been generated from this plant since the 1950's. Geothermal generation comes with its own set of environmental problems and associated costs.
God was my co-pilot, but then we crashed and I was forced to eat him.
No canola is not incredibly toxic. No idea where you got that idea. There are some crackpots here in the US who try to spread FUD about it. Rapeseed oil could be thought of as toxic (although people in India actually use it in cooking), but Canola oil is most definitely not toxic. Canola is grown right now exclusively for food oil.
They already use geothermal energy sources in Iceland, and in Italy. In Italy, I THINK the majority of it is used as power sources for research labs (but I could quite easily be wrong in this).
Oh and on the yellowstone bit, there is a huge amount of energy stored underneath yellowstone, but there are a lot of issues with that.
The caldera volcano in yellowstone erupts every 600,000 years or so, and the last one was 630,000 years ago. Scientists there have already seen signs of an increase in activity in deep in the crust over the last number of years, changes in surface temperatures (increasing), parts of the landscape bulging, they think the massive magma chamber is building up again.The release of pressure by tapping into the geothermal sources could help release some of the immense pressure that is building up, or, if they fuck up, a sudden release of pressure, and a weak point in the bulge could be all it takes to allow the volcano to erupt.
74,000 years ago Mt. Toba erupted in Indonesia (I'm working on memory of something I studied a few years ago in uni so I could be wrong on the Indonesia bit, but I do know that 2,500 kilometers away in the Indian Ocean 35cm of ash from Mt.Toba was discovered). I think about 3,000 cubic kilometers of material was ejected in its massive eruption , there would have been a global temp drop of 5 degrees (according to Michael Rampino). And there is evidence to show that around this time, there was a bottlekneck in the global human population, it went down to a few thousand world-wide (This bottleneck was identified because mutations in mitrochondrial DNA of humans, {whose rate of mutation is known, and is passed from mother to daughter} were used to work backwards in time to the bottleneck). Mt. Toba was a VEI8 volcano (VEI = Volcano Explosivity Index, rated by orders of magnitude), as has Yellowstone.
In Yellowstone National Park, a VEI8 has erupted there with a periodicity of approximately 600,000 years. These massive eruptions had ash zones that far outsized the ash zone of Mt. St. Helens (check out http://www.geolsoc.org.uk/template.cfm?name=Yellow stone2 (which had an ash zone that reached only 19 miles), which was a VEI5 and considered large by modern standards. The massive eruptions would have been 3 orders of magnitude larger than Mt. St. Helens, which caused a temperature drop of .10C, the affect on global temperatures of an eruption of such magnitude would have been massive. The ability of these massive volcanoes to spread ash & dust over massive distances is undoubtable.
An example of the correlation of eruptions and their ash zones would be, of an eruption that occurred in Bruneau Ridge around 10 million years ago. 1600 kilometres away, in Nebraska, in 1971 Mike Voorhies discovered fossilised remains of 200 rhinos, with those of camels, lizards, horses and turtles, which were dated to be 10 million years old. These animals all systematically showed signs of being killed by Marie's disease, a lung disease where the lungs where shredded by razor sharp ash particles and the animals affected choked on dust and ash, and drowned in their own blood. The fossilised remains were surrounded by two metres of thick ash. This ash, and ash from the site of the eruption were analysed, and found to match, exactly.
Also, for an interesting read, search for the transcript of "Supervolcanoes", it was aired on BBC2 a few years ago http://www.bbc.co.uk/ Sorry it's a little off topic!
While this reply is off-topic in regards to the story, I feel there is some stuff that should corrected.
The recurrence interval for large scale eruptions at Yellowstone ranges from 600Ka to 800Ka. That's a 200,000 year range. The last major eruption was ~640Ka ago.
That means it might erupt tomorrow, or it might erupt 120,000 years from now. Chances are, we won't be alive to see it when it finally happens.
It's also entirely possible that it might not have a major eruption ever again. The 600-800Ka recurrence intervals are based on only three large eruption events that have occured in the past 2 million years.
Currently, seismicity in the region is at relatively low background levels and there really isn't anything to worry about. We see the same sort of situation at Long Valley Caldera as well.
Regarding the grandparent's theory of how to use geothermal power: I have to say that I disagree with it. Just because there is magma down there doesn't mean it will be economically feasible to drill through the rock that the plant will sit on.
As the parent poster states, there are also possible drawbacks and consequences as well. It has been proven that earthquakes in The Geysers region of California (northwest of San Francisco) are caused by the injection of water into the ground. Whether this could lead to some bigger event in certain areas, we don't know.
The fact that the Hindenburg's paint pigments are the same compounds that are now the two main active ingredients in the space shuttle's solid rocket boosters has more to do with the fire than anything else. And, according to a Popular Mechanics article from sometime around 1996, the same thing happened in California in 1936 to another airship--this time filled with helium. So the hydrogen in the Hindenburg didn't do anything but exacerbate the existing fire.
Y'know, you blow up one sun and suddenly everyone expects you to walk on water.
I'm pretty certain it's Canadian Oil Low Acid.
Pure hydrogen flame releases heat in 2 ways--it produces a hot molecule (water of course) and it emits UV radiation. In the open, such photons are not as likely to be absorbed as readily as the IR photons that carbon fires put out.
p ro ject1/index.html
The guy who falsely suggests that the Hindenburg did not burn due to its hydrogen (he blames the skin, but I know someone who experimentally has shown that that kind of doped fabric burns at about 1/1000 the speed it would have had to to account for the destruction of Hindenburg)
http://www.sas.org/tcs/weeklyIssues/2004-12-17/
--anyway, Addison Bain makes a big deal of hydrogen flame's invisibility. Quite true. Except that the hydrogen flame inside Hindenburg was _inside_ a fabric skin that was _not_ transparent to these UV photons! All the heat released by burning hydrogen had nowhere to go until the skin burned up, and when it did that of course it emitted IR and red light like any other burning carbon substance. And more; the extra heat from the hydrogen (by far the biggest energy release around) would make the carbon glow even if it were not burning, like these hydrogen-flame detecting brooms or like the mantle of a gas lantern.
In the real world you rarely encounter pure hydrogen flames you see.
I grow Canola up in Alberta, Canada (hundreds of acres) and no the soil is not toxic. I can assure you that many weeds will still grow afterwards. I have to grow a crop next year (something other than Canola) and I can assure you that wheat and so forth still grow just fine after Canola.
You can even eat canola flowers. They taste like cabbage. Cattle get sick and die (something that I've never seen) probably for the same reasons that alfalfa kills cattle (in other words you can't graze cattle on alfalfa either).
So please. Stop spreading FUD, particularly in regards to pesticides and herbicides. Have you ever farmed before? Have you actually gone out and witnessed this toxicity of which you mention? I can assure you that farmers are highly sensitive to issues of herbicide toxicity and residue. Pesticides are a non-issue here since they are almost never used on Canola. Our lifeblood is the soil and the last thing we want to do is poison it.
Canola was specificly bread from rapeseed to get an edible oil. Rapeseed oil is high in acid content which is toxic in high doses. Whether or not Canola oil causes cancer (and any number of thousands of other food products) is a legitimate issue. But these other things you mention are FUD plain and simple.
I'm shocked and surprised to see someone actively spreading this misinformation. Your opinion on the health qualities of Canola oil is valid, but please don't spread this kind of FUD about something you know little about.