Questions about a Hydrogen Economy; Scientific American

[Ivan Seeking]

Spray-On Solar-Power Cells Are True Breakthrough

...Like paint, the composite can be sprayed onto other materials and used as portable electricity. A sweater coated in the material could power a cell phone or other wireless devices. A hydrogen-powered car painted with the film could potentially convert enough energy into electricity to continually recharge the car's battery.

The researchers envision that one day "solar farms" consisting of the plastic material could be rolled across deserts to generate enough clean energy to supply the entire planet's power needs. [continued]

http://news.nationalgeographic.com/news/2005/01/0114_050114_solarplastic.html

Also

ASU researcher gets grant to explore new methods of hydrogen generation

...Neal Woodbury, director of the Center for BioOptical Nanotechnology at the Biodesign Institute, is the principal investigator on the ASU grant, which he says will explore new ways to efficiently convert water into hydrogen. The research will focus on the development of new catalysts – materials that facilitate chemical conversion processes – for converting water to hydrogen. [continued]

http://www.eurekalert.org/pub_releases/2005-01/asu-arg012005.php

 

[Jake]

QUESTION: As far as water vapor polution, couldn't this be reduced a huge amount simply by running the exhaust pipe through some kind of heat disapater, thus turning it into liquid water? Then the water mostly would just off the road into dirt where it would be absorbed... or occasionally on hot days re-vaporize into regular precipiation anyway!

 

[willib]

Quantum Dots and Tunable Bandgap
The first advantage derived from the use of quantum dots stems from their tunable bandgap, which allows Evident to control the wavelength at which they will absorb or emit radiation. It is established that the greater the bandgap of a solar cell semiconductor, the greater the output voltage provided towards electricity generation. On the other hand, it is established that a lower bandgap results in a higher output of current for electricity generation, at the expense of a lower output voltage. Both high currents and voltages are desired for efficient solar-electric conversion. Thus, there exists an optimum bandgap that corresponds to the highest possible solar-electric energy conversion.

Evident is a company btw..

http://www.evidenttech.com/applications/quantum-dot-solar-cells.php
really interresting stuff..
http://www.google.com/search?hl=en&lr=&q=quantum+dots+Infrared+solar+cells

 

[Seafang]

I have to wonder how difficult it would be to reduce water vapor emissions to an acceptable level, whatever that might be. I suspect the technology already exists. It is true that nitrogen oxides are produced simply by heating air - no fuel required. But, it is also true they are easily reduced to negligible levels when you do not have the corequisite need to remove other hydrocarbon combustion byproducts. A variety of alternative energy sources for hydrogen production have already been noted in this thread. They all have various advantages and disadvantages, as do conventional fossil fuels. That does not mean they are unworkable, or even impractical. It is virtually certain costs would decline over time merely as a consequence of economies of scale. It is also probably safe to assume that technological advances would play a role. While I may have questions that have not been satisfactorily answered in my mind, that does not mean they cannot or will not be solved. It certainly does not mean there is no point in trying. I'm willing to concede I may have limitations that are not universally shared. The horseless carriage had its naysayers. It still turned out to be fairly practical and quite popular.

I'm not a chemist (at least not a good one) so I am not up on catalytic converters, but I am willing to believe that efficient suppression of nitrogen oxides could be possible if you don't have to worry about carbon by products as well, but I have no idea what the energy consequences of that are.

But I keep hearing complete disconects between methods of 'making hydrogen' and the concept of the conservation of energy. Making hydrogen from any of its common 'ores' will consume more energy than you get from either burning it or running it in your fuel cell. It is the source of THAT energy that everyone is looking for.

As for the water vapor GHG 'pollution', the global warming enthusiasts DO believe it is a problem. They cite heating of the atmosphere by CO2 trapping, as causing more oceanic evaporation, putting water vapor in the atmosphere which causes more warming; a POSITIVE feedback effect.

Of course I believe water vapor emission from vehicles is quite benign. The thermal efficiency of our engines would be higher if liquid water were emitted instead of hot vapors.

But why is everyone concerned about mechanisms that heat the air. The end goal is to cool the planet, and remove the solar energy that was absorbed in the oceans and the ground and ground cover. By far the most efficient mechanism of planetary cooling going on is evaporation of ocean water, into the atmosphere. About 590 calories per gram of energy is transported into the atmosphere, and the heated atmosphere rises (convection) until the water condenses out as raindrops at higher altitudes, thereby depositing that heat in the upper atmosphere, from whence it can be radiated to space. Even better if it can go higher to a colder region and form ice or snow crystals, and deposit another 80 calories per gram of latent heat of freezing. Water or ice clouds reflect sunlight back into space, and they alo absorb incoming sunlight at wavelengths longer than about 700 nanometers, in several water absorption bands from 0.7 out to around 4 microns. That direct absorption of sunlight by water LOWERS the ground level insolation cooling the planet..

If you take the two limit cases of zero water molecules in the atmosphere, and complete saturated water vapor and clouds from ground to 20 km or so all over the entire globe, it is quite apparent that you set in motion effects which will return naturally to the present status quo from either end. There is no evidence that there are multiple stable states in between those two extremes. There is one, that we have now.
Any mechanism that transfers heat energy from the ground/ocean to the atmosphere, whether it be by direct conduction due to contact with the ground, or radiation in the infrared, or evaporation of water, will lead to convective transport of that heat to the upper atmosphere, where it can finally exit to space. Evaporation is the most efficient by a long shot, so it is water vapor which regulates our planet's temperature; not CO2 or other trace gases.

Nonw of which helps us find another source of energy to make hydrogen energy storage medium.

 

[Ivan Seeking]

Hydrogen for Residential Combined Heat and Power

From the Energy Research Center of The Netherlands
http://www.waterstof.org/20030725EHECO3-132.pdf

 

[Seafang]

From the Energy Research Center of The Netherlands
http://www.waterstof.org/20030725EHECO3-132.pdf

An interesting paper; which however dodges the question of where you get hydrogen from.

So long as we have natural gas (fossil fuel) we have no need for the hydrogen; the NG is a perfectly good fuel by itself, providing the energy of combustion of the hydrogen as well as the carbon, and whatever chemical binding energy might be available.
Extracting the hydrogen from the NG has to be an energy losing proposition, so why do it; and you either end up with the same CO2 as before or else a pile of soot to be dealt with. It is still a Ponzi scheme. The problem remains what soures of energy we will have after the fossil fuels age.

As to your citations of cliches by Michio Kaku and other eminents; I don't get the point.

 

[Ivan Seeking]

An interesting paper; which however dodges the question of where you get hydrogen from.

So long as we have natural gas (fossil fuel) we have no need for the hydrogen; the NG is a perfectly good fuel by itself, providing the energy of combustion of the hydrogen as well as the carbon, and whatever chemical binding energy might be available.
Extracting the hydrogen from the NG has to be an energy losing proposition, so why do it; and you either end up with the same CO2 as before or else a pile of soot to be dealt with. It is still a Ponzi scheme. The problem remains what soures of energy we will have after the fossil fuels age.

If you look at the original article that motivates this thread, you will see that after converting NG to H2, the well to wheels efficiency of H2 fuel cells, for example, is better than NG powered fuel cells. This includes producing the Hydrogen from NG. The "soot" to be disposed of is valuable, high grade carbon that can be sold, which adds even more economic efficiency to the process. As for sources, this question is the primary point of this thread. You might also review the promise of ocean hydrates. https://www.physicsforums.com/showthread.php?t=58374

As to your citations of cliches by Michio Kaku and other eminents; I don't get the point.

I think you do, which is why you chose to comment.

 

[shrumeo]

From the document


So even if anthropogenic sources are small compared to natural sources (and absorbtion), these sources may well account for all of the increase in the atmosphere of carbon dioxide.

I tend to agree.

If we think of the Earth as mostly a closed system (except for the stray meteorite) then you have to fix carbon as fast as you oxidize it if you want to keep the atmosphere with the same amount of CO2 (does it matter?)

Unless photosynthesis can catch up with the rate that we dig carbon out of the ground and put it into the atmosphere, then there will always be a net increase in CO2.

QUESTION: As far as water vapor polution, couldn't this be reduced a huge amount simply by running the exhaust pipe through some kind of heat disapater, thus turning it into liquid water? Then the water mostly would just off the road into dirt where it would be absorbed... or occasionally on hot days re-vaporize into regular precipiation anyway!

Yeah, you'd be adding to the local humidity. Maybe if we all start driving in the desert it won't be so arid anymore.
I don't know if this is even something to worry about.

Evident is a company btw..

http://www.evidenttech.com/applications/quantum-dot-solar-cells.php
really interresting stuff..
http://www.google.com/search?hl=en&lr=&q=quantum+dots+Infrared+solar+cells

Don't get any CdSe on you or in you!

That would be the main complaint with this technology.
You'd be painting you sweater with quite toxic stuff.

Also, I can't see these cells in anything but niche markets, mainly because of the way the quantum dots are produced and their toxicity.

I think though that the use of the HIGHLY toxic dimethyl cadmium as a precusor has been replaced by the use of cadmium oxide for large scale preps.

But, think of the stink over lead in paint and then realize you'd be painting everything with cadmium (which isn't quite as toxic as mercury).

There are ways around this, by coating the particles with something moire inert, but eventually and inevitably, the Cd and Se will both leach out to wreak their havoc.

Anyway, people won't stand for it (even if it won't hurt them).

 

[Ivan Seeking]

Oregon may lead future of wave energy

CORVALLIS, Ore. – Significant advances in university research and other studies in the past two years are pointing toward Oregon as the possible epicenter of wave energy development in the United States.
This may lead to a major initiative to expand a technology that is now in its engineering infancy, and tap the constant heave of the oceans for a new era of clean, affordable and renewable electrical power.

Electrical engineers at Oregon State University have pioneered the development of technologies to take advantage of wave power in ways that are reliable, maintainable and able to survive a hostile ocean environment. The OSU College of Engineering also has a host of other facilities that would make it an ideal site for more advanced research.

Last fall, the Electric Power Research Institute finished a study which concluded that a site off Reedsport, Ore., would be the optimal location in the entire nation to develop a wave energy test and demonstration facility. [continued]

http://www.eurekalert.org/pub_releases/2005-02/osu-oml020105.php

 

[ohwilleke]

Keep in mind that lots of industrial processes already generate water vapor, probably in greater volumes than cars operating on hydrogen would. For example, coal burned in power plants has a significant water contents that is converted to steam.

It is hard to see hydrogen fuel emmission being significant compared, for example to vaporization of water from the surfaces of oceans that make up 70% of the planet. Moreover, if water is the source of the water vapor, you could end up having a source and sink that balance out. There is no obvious reason that increased water emissions increase atmopheric carrying capacity for water vapor significantly.

 

[Seafang]

If you look at the original article that motivates this thread, you will see that after converting NG to H2, the well to wheels efficiency of H2 fuel cells, for example, is better than NG powered fuel cells. This includes producing the Hydrogen from NG. The "soot" to be disposed of is valuable, high grade carbon that can be sold, which adds even more economic efficiency to the process. As for sources, this question is the primary point of this thread. You might also review the promise of ocean hydrates. https://www.physicsforums.com/showthread.php?t=58374



I think you do, which is why you chose to comment.

Well Ivan, I am quite used to presenting my thoughts and beliefs in words, either spoken or written; so I would caution against INFERRING anything from anything I say or write. If I wanted to IMPLY anything, I would state it specifically; so when I said "I don't get the point", I MEAN EXACTLY THAT. (fancy that the caps lock came on by itself, and I didn't mean to shout).

Each of the persons you cited is eminent in his field as a scientist or engineer. None of them is eminent in the field of philosphy.

 

[Chronos]

Well Ivan, I am quite used to presenting my thoughts and beliefs in words, either spoken or written; so I would caution against INFERRING anything from anything I say or write. If I wanted to IMPLY anything, I would state it specifically; so when I said "I don't get the point", I MEAN EXACTLY THAT. (fancy that the caps lock came on by itself, and I didn't mean to shout).

Each of the persons you cited is eminent in his field as a scientist or engineer. None of them is eminent in the field of philosphy.

And you make arguments that make no sense. I agree with Ivan. By the way, what in the world does philosophy have to do with this discussion? I thought we were talking about science. I don't get your point either, assuming you even have one.

 

[Ivan Seeking]

"Ethanol has the potential to be an integral part of the emerging hydrogen economy. Its properties make it an excellent liquid fuel for the extraction of hydrogen."
October 29, 2004
Des Plaines, Illinois [RenewableEnergyAccess.com]

Ethanol is commonly touted as an alternative fuel suitable for any vehicle. Researchers from the Gas Technology Institute (GTI) have produced hydrogen from the corn-based product, however, and that could shift ethanol into a whole new fuel market.

For the past six months GTI engineers have done research to demonstrate the potential of its fuel processor technology that is used to generate hydrogen from a variety of renewable fuels. A steam powered two-step, reforming-shift fuel processor is used for the conversion.

"We believe GTI is now strongly positioned to develop and deploy both stationary and transportation energy systems utilizing ethanol to hydrogen reformation," said Gerry Runte, who is the executive director of GTI's Hydrogen Systems Center. "We were able to produce a high-quality hydrogen gas from ethanol, similar to results using natural gas, and demonstrated our process to representatives of the Renewable Fuels Association (RFA)."

GTI is also developing a fueling station platform for a natural gas to hydrogen fueling station, and the institute would like to create an ethanol to hydrogen station based off of the same plans. Researchers are also pursuing the use of ethanol for stationary fuel cell demonstrations.

"Ethanol has the potential to be an integral part of the emerging hydrogen economy. Its properties make it an excellent liquid fuel for the extraction of hydrogen," said Runte.

The institute has over three decades of experience in converting a variety of fuels into hydrogen, according to the company press release. They use an optional passive carbon monoxide (CO) control system that consistently produces less than 4 ppm CO without requiring complicated control systems. The unit is adaptable to use either fuel cell anode recycle gas or pressure swing adsorption off-gas recovery for efficient supplemental heat generation.

http://www.maui-tomorrow.org/issuespages/energy/ethanol_hydrogen.html

 

[ohwilleke]

Ethanol is probably more practical in the short to medium term as a liquid fuel replacement than as a hydrogen replacement. The biggest problem with ethanol is that even using a large portion of the entire agricultural output of the United States you are making only a modest dent in U.S. oil consumption.

Ethanol may ultimate be the primary liquid hydrocarbon fuel when oil supplies grow very expense to tap. But, it is not a good total solution.

 

[Ivan Seeking]

I think a key concept in all of this is diversification. The beauty of using H2 as the base energy carrier is that it allows for a standardized fuel that has many, many sources. I would expect that any number of competitive methods for H2 production will emerge. Some will be based on existing hydrocarbons sources such as ocean hydrates and natural gas, coal, ethanol and the like, and others will come from biomass consumption and other bacterial processes. I suspect that wind to H2 through water will prove viable in wind friendly areas, solar to H2 will be used in solar friendly areas. Even nuclear energy may be used to make the stuff. Also, as the economic benefits of a hydrogen economy become clear, industry will find many ways to produce H2 for resale as as byproduct of existing processes.

If one reviews the first page of this thread and the many links throughout, one will see that dozens of promising methods are explored for H2 production.

 

[Seafang]

A review of the links given in the Hydrogen thread addresses the many methods explored for producing H2.

Russ, I think your concerns are completely valid. You and I have already hashed this out pretty well in the thread linked and I realize that we disagree on questions of production. I will only say that this is a core issue being addressed on many fronts, and that many scientists feel that this is not a show stopper; but that much work is still needed.

By no means is this a done deal. To "Go Hydrogen" could still mean many different things depending on how the technologies pan out.

Finally, I make no bones about my motives here. I think we need many brains filled with thoughts of Hydrogen. Politically, economically, scientifically, and environmentally, H2 strikes me as our best hope to finally end our addiction to oil. The political motivation is now more obvious than ever. Bye bye OPEC!

Well so we get off our addiction to oil, and we make hydrogen; well the natural critters make it for us out of sunlight. So what Hydorgen ore do you suggest they use.

Is it Water? Tell us how many hydrogen production technologies (of the natural non man made kind) start of with water as the hydrogen ore. Is it a number greater than zero. I'll bet that most if not all don't start with water; they start with some sort of hydrocarbon, and we immediately remove coal oil and natural gas from the list no fossil fuels allowed remember. that leaves probably some plant materials; bu they are still hydrocarbons; ethanol is a hydrocarbon.

SO WHA T DO WE DO WITH ALL THE SOOT.

 

[Ivan Seeking]

Those are not only silly questions, they are also already answered in the many links provided. Read and learn.

 

[Ivan Seeking]

SO WHA T DO WE DO WITH ALL THE SOOT.

And I already answered this.

The "soot" to be disposed of is valuable high grade carbon that can be sold

Right now much of it goes into the air as carbon monoxide and dioxide. Much better.

 

[Chronos]

Perhaps a cowpie economy is worth exploring. Judging by this thread, it appears to be a renewable energy source.

 

[Ivan Seeking]

Could you elaborate a bit?

 

[Ivan Seeking]

Hydrogen-powered bike is too quiet

It can reach 50mph in 12 seconds, produces no emissions and is as quiet as a laptop computer - but that could be a problem.

...But engineers are considering adding an artificial "vroom" as they were worried its silence might be dangerous. [cpntinued]

http://www.ananova.com/news/story/sm_1321345.html?menu=

Some engineers were talking about this issue of sound on the recent SA Frontiers special about Hydrogen. One person mentioned that electric cars will be very boring as race cars. It is hard to imagine a field of nearly silent Grand Prix cars gearing down for the hairpin turn.

 

[hitssquad]

One person mentioned that electric cars will be very boring as race cars.

Why might race cars run on electricity instead of gasoline?

 

[Ivan Seeking]

Have you seen the T-Zero? http://www.acpropulsion.com/tzero_pages/tzero_home.htm

Already we have an electric car that outperforms most high performance autos. Also, IIRC, the advanced concepts engineers at GM were interviewed and I am citing their expectations.

I am pretty sure that the show can be watched online...in fact there should be a link in this thread. edit: Also, I am pretty sure that the prototype could do 0-60 in 3.0 seconds. The production car is claiming 4.1 seconds.

 

[Ivan Seeking]

This is it.
http://www.pbs.org/saf/1403/

 

[Chronos]

I agree with Ivan. Viable alternatives to hydrocarbon energy sources are well inside the radar screen. Already the nuclear option has become politically viable. I predict at least 50% of new energy production in the US will be fission based by the end of this century - nuclear power will come back with a vengeance. The advantages, particularly given technological advances, are too attractive to ignore any longer. Engineers will once again save the day! If it's any reassurance, the fate of humanity lies in people like me... plays spooky music

 

[Ivan Seeking]

Hah! A nuclear fan.
What convinces you that we can operate nuclear plants safely. That is to say, what new nuclear energy technologies make this a viable approach?

 

[hitssquad]

Viable alternatives to hydrocarbon energy sources are well inside the radar screen.

Features vs. benefits. What was questioned was not the existence of alternatives to hydrocarbons. What was questioned was the benefit of switching.

 

[hitssquad]

Have you seen the T-Zero?

The T-Zero runs on chemical energy cell batteries, not on fuel cells. Are you talking about race cars running on batteries or fuel cells? Do you know what specific energy and specific power are? Do you know how much energy is in a typical gallon of gasoline? Do you know what the efficiency of conversion of fuel cells currently is and what it is expected to eventually be?

 

[Ivan Seeking]

I repeated the quote about electric cars. I never said anything about fuel cells.

Edit: oh yes, yes, yes, and yes. Get a grip.

 

[hitssquad]

The motorcycle you linked to runs on a fuel cell. Do you think on-road electric vehicles might run better on batteries, fuel cells or something else? What might electric race cars run better on?

 

[Chronos]

Hah! A nuclear fan.
What convinces you that we can operate nuclear plants safely. That is to say, what new nuclear energy technologies make this a viable approach?

Elementary, my dear Ivan. I've been instrumental in building 3 of them. They have all been operational for at least 20 years and not a single one has suffered a melt down - and I've also been nominated for village idiot for the 5th straight year. It's not a large village, but a village nonetheless.

Check out these designs. They are pretty impressive:

https://www.pbmr.com/
http://gt-mhr.ga.com/

 

[Ivan Seeking]

Do these use ceramic coated Pu pellets?

Enlighten us about melt-down proof technologies. A friend of mine was working on this but he is now retired, leaving me out of the loop. Also, can you tell us anything about fast-flux reactor technologies?

 

[hitssquad]

Do these use ceramic coated Pu pellets?

They use graphite pellets, each containing a tiny flake of uranium. PBMRs are illegal to implement in the United States because they are so dangerous (the graphite can burn and the reactor is intended to be built without a containment, meaning that each of the thousands of mass-produced pellets needs to have its integrity assured to the same degree that single containments need to have their integrity assured today). Other countries are interested in them though.

 

[Ivan Seeking]

The ceramic approach seemed promising. In principle the separation between the Pu beads [pellet cores] assures that a meltdown is impossible. The ceramics can withstand any temperature that might be reached in the event of a catastrophic cooling failure.

 

[Chronos]

The PBMR design uses a silicon carbide coating on the fuel elements, not graphite [where did that come from?]. Reading the links is recommended. There is no meltdown risk. The status of design reviews in the US can be found here:
http://www.eia.doe.gov/cneaf/nuclear/page/analysis/nucenviss2.html