Posted on 11/12/2007 10:45:42 PM PST by Rick_Michael
Power in watts x time = joules which is a measurement of energy.
I was careful to keep power in watts and not call it energy. It is assumed that time is the same on the input and output sides of the energy converter (electricity and chemical energy conversion to hydrogen). If you put in 1 watt of electrical power for 1 minute and get a flow of 3.88 watts of hydrogen power for 1 minute the energy gain (only counting the electrical energy being put in, not the chemical energy being put in) is an energy gain of 288% which is what the article claims. This is clearly possible and not simply a claim of getting free energy from some mysterious source in the universe... The energy gain is coming from the chemical energy of the acetic acid that is also consumed in the process along with the electricity.
I'm guessing the reference of energy gain regarding only the electricity going in is to show that there is much more involved than just electrolysis in the hydrogen generation. Electrolysis only would be less than 100% conversion ratio.
neverdem posted more detailed information and the overall energy conversion efficiency was claimed to be 82%. This is based on the electricity and acetic acid that is consumed to make the hydrogen. All of which sounds realistic and useful for the generation of hydrogen.
“And I get damned tired of scaremongers like you constantly harping on “how dangerous” it is.”
I don’t think it is that dangerous, it’s just the more you know about it, the less it makes sense. I won’t spend anymore time trying to educate you, apparently you are just getting angry.
Then why do you keep harping on that issue.
"...it’s just the more you know about it, the less it makes sense.
If you can get substantial energy from the proposed process with the claimed efficiency, then it "does" make sense. I don't know if the bacteria used are (or can be) photosynthetic, just "biomass eaters", or whether you can use a mix of both, with the photosynthetic bacteria (algae??) providing the biomass to the "eaters", but in either case, you convert a (or many) waste product(s) into high quality energy (and hydrogen IS high quality energy, because it can be readily converted into electricity which high efficiency). Since the electric current required for the actual conversion process is more or less catalytic, if that is gotten from photovoltaics, then the only energy required is to obtain and transport the biomass.
"..I won’t spend anymore time trying to educate you, apparently you are just getting angry.
Believe me, on this topic I don't need the education, you do. And what gets me upset is folks who deny proven facts-one of which is the long history of safe production and use of hydrogen.
That covers the evaluation of the generation of the hydrogen. How much additional effort is required to maintain the reaction vessels? I'm thinking in terms of the total process as a going business operation. Is it going to be a net positive cash flow or another loser living on taxpayer subsidies? Assuming the overall process looks viable, there is still the issue of adequate infrastructure to support practical travel in a hydrogen powered vehicle.
If you were that familiar with the production and use of industrial hydrogen, you would know that the majority of hydrogen production is made and used at the same site because of the difficulty with bulk storage and transportation.
Compressing, packaging, trucking and recycling of containers uses about as much energy as there is in the bottles. That is the reason the delivery truck is running on diesel instead of hydrogen.
Biomass can be turned into ethanol through biological means, bio-oil (diesel) through thermal means or about any petrochemical using syngas as an intermediary. All of which can be reasonably shipped.
The PEM fuel cell is not very robust and there are many technical issues that stand in the way of general use. Also, the diry secret is that they are not much more efficient that a diesel engine. Right now, they are only about 10% better in energy conversion but suffer from using hydrogen, an inferior fuel.
When making hydrogen from petrochemicals or biomass, you are taking a stable energy rich compound, breading the C-C and C-H bonds which are nicely energetic and provide all of the characteristics of a good fuel, easy to transport and low vapor pressure (varies with the compound) and create a fuel that is difficult to handle and left up to inself would escape into space.
BTW, look at my posts, I have not said it was unsafe, just hard to handle. If you spill hydrogen, is is gone, not likely to explode or contaminate the environment just plain gone never to be seen again. The problem is that it is very hard not to spill.
I started out on the hydrogen bandwagon about 10 years ago. It is education that has soured me on the idea. Rather than point fingers at me, try looking at both sides of the issue.
BTW, hydrogen is not nor has it ever been a source of energy. The question is whether it is a reasonable transport medium for energy. I put to you that it is not. If you have a way to produce hydrogen that is so much cheaper than producting a better fuel, you would be better off converting that hydrogen at the site of production using SOFC or one of the other high heat fuel cells and transport that energy with power lines to where you need it. SOFC with heat recovery can be close to 70% efficient with transmission lines over 90% efficient, getting more than 50% of the energy to the endpoint. Trucking hydrogen bottles based on whose numbers you look at can get anywhere from less than zero to about 20% of the hydrogen energy to where you need it and then you still have to turn that into electricity with the associated losses. It would make more sense drive a steam operated car directly off the biomass, at least it would be about 10% efficient.
I’ve read the rah-rah hydrogen sites, there is more information available.
This is just one data point in a much larger energy system.
I have no real idea if it is economical overall though there are indications it may be. My only real point was that the creator of this technology wasn’t obviously pulling a fast one with the claim of “free energy” like so many others that get posted here.
And as far as infrastructure and cars, it is as simple as this - if, and that’s a big if, hydrogen (or any other fuel) becomes more economical to produce on a large scale per unit energy than gasoline capitalist will build the infrastructure and cars that are needed because there will be money in it.
Who knows what the future holds, but I tend to think that if there were a cheap source of hydrogen it should be used for the production of electricity. Battery technology has been rapidly improving over the last several years and there’s no indication that it won’t continue. Practical electric cars are all about batteries.
In the final analysis, it is all about economics. It dies if it is a losing proposition...unless the socialists decide to subsidize it from the taxpayer's pocket. There's plenty of that kind of behavior in the rail industry.
I'm well aware of EVERYTHING in your posting, and I simply disagree. The only point worth responding to is the one above, and that is to point out that hydrogen pipeline transport of energy is MORE efficient than transmission lines at long distances. I don't recall off the top of my head exactly where the crossover point is. If we end up doing large scale photo voltaic (new cells 42% efficient), say, in the desert Southwest, pipeline is the ONLY practical way to get the energy from there to the Northeast. Superconducting transmission lines are "pipe dream".
And hydrogen is NOT all that hard to handle. THAT is the point I keep trying to get through to you---we KNOW HOW TO DO IT. So you're right back to harping on how unsafe it is.
hydrogen is so...explosive.
People being people - I am imagining all sorts of terrible accidents for workers at the plants - and also for drivers in unfortunate accidents.
Can anyone put my mind at ease?
Hydrogen explosions would go upward...gasoline fires/explosions would rest upon the ground and be much more dangerous.
Zeppelin...is on your mind.
so...if a hydrogen engine blows - it is going to blow straight into the air without taking the rest of the car with it?
http://www.rmi.org/sitepages/pid205.php
This might sound unintuitive. But when a carbon-based fuel like gasoline burns, glowing hot soot particles transfer the heat to its surroundings — potentially including you. But because hydrogen contains no carbon, it burns cleanly without a residue of hot soot, producing little radiant energy. This means that a victim would have to be practically in the flame in order to get burned.
Pressurized hydrogen tanks are made to withstand enormous impacts, and fail gracefully, if at all. Some fear that a hydrogen tank has the potential to explode, and that is possible. But these critics often overlook the greater explosive potential of the gas tanks in their very own cars.
Many real-life tests have demonstrated the safety of pressurized hydrogen storage. Simulated 55 mph crash tests left the car totaled, but the hydrogen tank intact. To prove the safety of its hydrogen vehicles, BMW tested its hydrogen tanks in a series of accident simulations that included collision, fire and tank ruptures. In all cases, the hydrogen cars fared as well as conventional gasoline vehicles. And hydrogen-fueled cars are designed to preclude the possibility of leaked hydrogen collecting within the vehicle.
thanks for the info. You’ve helped my case of hydrogen-paranoia.
Novel technique for cheap and abundant hydrogenThe new method developed by engineers at Pennsylvania State University in University Park, U.S., 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 environmental engineers Shaoan Cheng and Bruce Logan 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 per cent of the theoretical maximum yield using aetic acid, a common dead-end product of glucose fermentation. "This process produces 288 per cent more energy in hydrogen than the electrical energy that is added in the process," said Logan... One of the immediate applications for this technology is to supply the fuel for electric fuel cell vehicles – but it could also be used to convert wood chips into hydrogen to create fertiliser, said the researchers.
Agence France-Presse
Tuesday, November 13, 2007
COSMOS magazine
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