Breakthrough car runs on water!! Or not.
Here’s another past post, reposted from my other blog.
TOKYO (Reuters Life!) – Tired of petrol prices rising daily at the pump? A Japanese company has invented an electric-powered, and environmentally friendly, car that it says runs solely on water.
Genepax unveiled the car in the western city of Osaka on Thursday, saying that a liter (2.1 pints) of any kind of water — rain, river or sea — was all you needed to get the engine going for about an hour at a speed of 80 km (50 miles).
“The car will continue to run as long as you have a bottle of water to top up from time to time,” Genepax CEO Kiyoshi Hirasawa told local broadcaster TV Tokyo.
“It does not require you to build up an infrastructure to recharge your batteries, which is usually the case for most electric cars,” he added.
Once the water is poured into the tank at the back of the car, the a generator breaks it down and uses it to create electrical power, TV Tokyo said.
Whether the car makes it into showrooms remains to be seen. Genepax said it had just applied for a patent and is hoping to collaborate with Japanese auto manufacturers in the future.
Most big automakers, meanwhile, are working on fuel-cell cars that run on hydrogen and emit — not consume — water.
(Writing by Chika Osaka, editing by Miral Fahmy and Chang-Ran Kim)
You can’t run a car on water.
It’s bogus, baloney, BS. Anybody that tries to tell you otherwise is trying to scam you.
I suspect that I don’t at all have to convince most of the regular readers of this blog of this fact, but I just needed to state that, for the record, if you will.
You can use electrolysis to generate hydrogen from outside the car, and have a tank of hydrogen in your car, but that’s not a water-powered car, it’s an indirectly electrically powered car, using hydrogen as an energy storage medium. No such technology is especially novel, and it’s certainly far from impossible.
There’s also the option of using the sulfur-iodine cycle to disassociate water into hydrogen, using thermal energy – however, in practice, this disassociation is, overall, not dissimilar to the electrolysis of water, other than in that it employs thermal energy directly as opposed to electricity, and can be considerably more efficient than electrolysis, especially when thermal energy is used directly from a heat source – such as a nuclear reactor – as opposed to driving a heat engine to generate electricity from the nuclear reactor, followed by electrolysis.
(Aside: The SI cycle was invented at General Atomics in the 1970s, and the Japanese Atomic Energy Agency (JAEA) has conducted successful experiments with the process with the intent of using high temperature Generation IV nuclear fission power reactors to produce hydrogen on a large scale.)
For that reason, I will focus on electrolysis for this post, but just remember that in terms of stationary generation of hydrogen, the SI process could be substituted anywhere where electrolysis is mentioned.
The fundamental claim of the water-powered car is that electrical energy from the car’s electrical system is used to generate hydrogen via electrolysis of water in situ, which is burned in the internal combustion engine, generating energy.
Alternatively, it might be claimed that water can spontaneously be disassociated into hydrogen, without any energy input.
It’s a ridiculous claim. It’s simply a matter of basic physics.
Let’s start with this.
Thus, the standard potential of a water electrolysis cell 1.23 V at standard pressure and temperature. The positive voltage indicates the Gibbs Free Energy for electrolysis of water is greater than zero. The reaction cannot occur without necessarily adding energy. It is just not thermodynamically favorable.
Electrolysis is not perfectly efficient, of course. It does not convert 100% of the electrical energy into the chemical energy of the resulting hydrogen. The process requires higher voltages what would be expected based on the cell’s total reversible reduction potentials. This excess potential accounts for what is known as electrochemical overpotential. The extra energy supplied, corresponding to these overpotentials, is eventually lost as heat. The reaction overpotential for the oxidation of water to oxygen at the anode is the dominant overpotential in the process, and an effective electrochemical catalyst to facilitate this reaction does not exist.
Platinum alloy electrodes are the default state of the art for this oxidation. The reverse reaction, the reduction of oxygen to water, is responsible for a significant contribution to electrochemical inefficiency in hydrogen-oxygen fuel cells.
Developing a cheap and effective electrochemical catalyst for this reaction would lead to increases to efficiency in both water electrolysis and in hydrogen-oxygen fuel cells – but efficiency can only be increased incrementally towards the ideal 100% – it cannot ever exceed 100% efficiency, of course.
Catalysts are pretty cool, and extremely useful, but they don’t violate the laws of thermodynamics.
The formation of hydrogen gas at the cathode can be electrocatalyzed with almost zero reaction overpotential by platinum, for comparison. Platinum is, of course, an expensive metal, but it is widely used in these applications.
The theoretical maximum efficiency of the electrolysis of water is between 80–94%, whilst in real world, practical contexts, the efficiency achieved is typically around 60%.
It should be obvious to everybody, then, that you cannot generate hydrogen in an electrolytic cell and convert it back to energy in a fuel cell which you then use to generate more hydrogen.
If this could happen with perfect efficiency in all steps then you would have a perpetual cycle from which no useful work can be extracted. Since it can not, does not and will not occur with perfect efficiency in all steps, then it’s basically nothing at all, besides nonsense.
In real-world terms, with an efficiency of around 60% for the electrolysis, and efficiency of 30% or less for energy conversion in the automobile engine, you’re considering an overall efficiency of well under 20% – it simply does not and cannot work.
We have yet another company basically claiming to have invented a perpetual motion machine.
It’s bogus. No, I don’t consider it “unscientific” to come right out and say that, with 100% certainty.
Thermodynamics-violating scams are at least as old, probably older, in fact, as the understanding of the laws of thermodynamics.
Should we wait and see if more data, results, demonstrations or peer review become available? No. I, for one, wouldn’t bother.
Look at Steorn. Remember them, making headlines a year or two ago? They were going to have peer review of the technology, and public demonstration, and all sorts of proof to convince the naysayers. Have we seen any of it delivered? Nope!
As gas prices rise, and energy becomes a central political topic, more and more people are suckered into taking a second glance at “free energy” peddlers.
There’s no need to be “open minded” about any possible wonderful hitherto unknown scientific discoveries here – it’s entirely just the same old snake oil.
By all means, let’s be open minded, but no so open minded that our brains drop out.
“The law that entropy always increases holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell’s equations — then so much the worse for Maxwell’s equations. If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation.” – Arthur Eddington.
However, let’s just assume, for a moment, that you can do it.
Let’s assume, just for the sake of argument, that water can magically be disassociated into hydrogen with no energy input.
1 litre – or 1 kilogram – of water will yield 119.2 grams of hydrogen. Combustion of hydrogen yields 143 kJ per gram – therefore, the energy content of water in this form is just over 17 MJ per kilogram.
Gasoline has an energy content of about 47 MJ/kg – therefore, the “fuel economy” of the hypothetical car that can somehow do what we’re describing here is intrinsically limited to being about 2.8 times worse than a conventional petrol engine.
Bright readers will note that the story referenced above refers to a speed of 80 km (50 miles). Yeah, sure – I’m not sure who’s to blame here – the journalists or those people making the claim. I think they’re both as bad as one another.
Maybe we’ll operate on the assumption that they mean 80 kilometers per hour. That means they’re claiming the “fuel efficiency” as 1 litre of water per 80 kilometers. That’s 1.25 L/100 km, corresponding to the equivalent of 68 miles per gallon or 3.46 L/100 km in normal petrol consumption terms. Well, that doesn’t seem so bad at all – aside from the fact, remember, that it’s impossible.
There is, however just one way, in principle, that a water powered car can conceivably work, without violating any of the laws of nature.
This would have to involve liberation of hydrogen from water via electrolysis, followed by energy generation by means of nuclear fusion of the hydrogen.
Suppose your car’s tank is fueled with 1 litre of light water. Given that deuterium constitutes 0.015% of natural water on Earth, one litre of water contains only 16.7 milligrams of deuterium. But that deuterium packs quite a punch.
I’m not sure, quantitatively, how much of an effect the isotope kinetic effect of deuterium will have on the electrolysis of heavy water. Probably a measurable effect indeed, but for the purposes of argument we’ll ignore it. The energy input required for the production of one molecule of hydrogen via electrolysis is equal to E = 1.23 V * 2 * e / 60%; where 60% is the efficiency, as previously mentioned, or 4.1 electron volts per molecule of hydrogen.
That’s a significant amount of energy relative to the heat of combustion of hydrogen, which is 3 eV per molecule of hydrogen, however it is completely insignificant relative to the millions of electron volts yielded from nuclear fusion processes.
Of course, essentially all anthropogenic nuclear fusion technologies, in existence or under development, at present utilize the much easier ignited deuterium-tritium reaction. When we start with nuclear fusion in a mass of deuteron plasma, 50% of reactions will yield He-3 from the deuterium, and 50% of DD fusion reactions will yield tritium as the reaction product – but under these conditions, the tritium nucleus will fuse with deuterium straight away, releasing a whopping 17.6 MeV.
Tritium burns so well in a deuterium plasma that it is almost impossible to extract from the plasma. The D-He3 reaction is optimized at a much higher temperature, so the burnup at the optimum D-D fusion temperature may be low, so it seems reasonable to assume that all the tritium, but not the He-3, gets burned up and adds its energy to the net reaction.
Add all that up and you end up with about 6.25 MeV per deuteron.
Five billion joules from a litre of water.
If a typical car requires, say, 8L of petrol per 100 km, then that’s about 300 MJ of energy content per 100 km of driving.
What if you really could drive your car almost 1700 km on a litre of water? Perhaps some day you will.
It can’t be done, of course.
There is, at present, no working, mature technology available that can usefully generate energy via nuclear fusion (with the exception of a Teller-Ulam bomb, and that’s of debatable usefulness.), let alone a fusion reactor capable of fitting within and operating within a car.
But there is absolutely nothing, in terms of the natural laws, that precludes it. It’s not at all physically impossible – it’s an engineering problem. Water-powered cars – real water-powered cars are a fantastically interesting thing to dream about, but we won’t be driving them in the foreseeable future.
But, later in the month… we got some updated news on the magical water powered car. It turns out that those pesky laws of thermodynamics caught up with them after all.
Kiyoshi Hirasawa, president of Genepax Co Ltd, unveiled part of the reaction mechanism of the company’s new fuel cell system called “Water Energy System” in an interview with Nikkei Electronics.
The system, which is capable of generating power with water and air, was first presented June 12, 2008. As reported in our previous article, the system produces hydrogen through a chemical reaction between water and a metal (or a metal compound) on the fuel electrode side (See related article).
Genepax uses a metal or a metal compound that can cause an oxidation reaction with water at room temperature, the company said. Metals that react with water include lithium, sodium, magnesium, potassium and calcium. The main feature of the Water Energy System is that it can be operated for a longer period of time by controlling the reaction of the metal or the metal compound, the company said.
According to Genepax, the metal or the metal compound is supported by a porous body such as zeolite inside the fuel electrode of the membrane electrode assembly (MEA). The products of the hydrogen generation reaction dissolves in water, and the water containing them will be discharged with water inside the system. Upon the completion of the reaction, the generation of hydrogen and power stops.
There is nothing revolutionary here – nothing that violates the laws of physics. Rather than “running on water” the device if fuelled with chemical potential energy in the form of a reactive chemical – such as lithium metal – that will spontaneously reduce water to hydrogen gas on contact, consuming the lithium. Energy is “stored” in such a material, which requires considerable energy input to create, and does not occur in the free metallic form in nature.
This is essentially nothing more than a non-rechargeable chemical battery. When its chemical “fuel” is depleted, it doesn’t work, and the chemical material must be replenished.
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You’re currently reading “Breakthrough car runs on water!! Or not.,” an entry on Nullius in Verba
- September 15, 2008 / 3:26 pm
- automotive technology, bad science, baloney, chemistry, energy systems, hydrogen, Physics, thermodynamics, water