Talk:Water powered car

Move to "Water-powered car"?
A link to Water-powered car has been sitting in RationalWiki:To do list for some time. I think that "water as fuel" claims are not limited to HHO, and the claims about "HHO gas"/"Brown's gas" (wp:Oxyhydrogen) are not limited to automobile fuel, they warrant a separate article.--ZooGuard (talk) 19:34, 7 April 2011 (UTC)
 * Sounds good. ТyUser_talk:Ty 19:35, 7 April 2011 (UTC)
 * I think I did it under this title because I spotted a redlink to it, but if "Water Powered Car" is also sat on the To Do List, that's a fine move. 20:12, 7 April 2011 (UTC)
 * I don't understand: "The popularity of this form of scam may be due to the misconception that hydrogen is some form of fuel, when in fact it's a form of energy storage." Fuel is matter that can be used to harness energy.  Maybe hydrogen-powered cars don't exist except as prototypes, but it could be used as fuel.  And what's a "form of energy storage" that's different than "fuel"?  sterile 11:41, 8 April 2011 (UTC)
 * It's energy storage because hydrogen isn't a naturally occurring substance in the same way that solar energy is or that oil/gas/coal are (although these are also energy storage, but naturally occurring and long term). Hydrogen is just a way of getting that energy into a car engine. You still need energy to produce it, which comes from a conventional fuel source - e.g., electricity from a coal-fired power station. When people think of hydrogen as a fuel, they seem to think that it's some piece of ultra-clean magic source of energy - it is emphatically not this as you have to generate it in the first place. Think of it the same way as a conventional electric car running on batteries, you either burn it burn it in an internal combustion engine or in a power station but you still burn it. Hydrogen is the same, but instead of storing energy in batteries, you store it in the form of reduced hydrogen, which can be oxidised to release energy with water as a by-product. The main barrier to the "hydrogen economy" is generating the electricity to produce it using renewable sources - hopeful by photocatalysis, if not electrolysis with power from renewable energy. 12:05, 8 April 2011 (UTC)
 * I get that, although the researcher who investigate ways to make hydrogen directly through chemical processes in the sun do call hydrogen a "solar fuel." I guess I see it as hair-splitting.  sterile 12:47, 8 April 2011 (UTC)
 * I'd probably define a "fuel" as something we don't need to put chemical energy into to form. So coal, oil, gas, uranium and so on are fine because that's just an extraction cost and maybe a little bit of cleaning up. Hydrogen, and chemical batters do undergo chemical reactions to form. 12:53, 8 April 2011 (UTC)
 * Except, of course, the photoreactions that made the biomass that became fossil fuels! :) sterile 15:51, 8 April 2011 (UTC)
 * But we don't do that, which is the distinction I was trying to make. 15:52, 8 April 2011 (UTC)

HHO
this would be called hydrogen hydroxide, right? And it'd have to be a positive ion of hydrogen to bond? Just trying to remember high school chemistry.-- 12:15, 15 June 2011 (UTC)
 * It seems that it's a crank term for oxygen-hydrogen mixture produced by splitting water. There are other claims attached to it, so it needs an article, and this one needs to be fixed, but this involves reading crank websites. And I don't want to read crank websites at the moment.--ZooGuard (talk) 12:19, 15 June 2011 (UTC)
 * I was just curious. if only adk were still here...--  12:21, 15 June 2011 (UTC)

A reference to water-powered vehicles
This article could use some historical context. I don't have any specific references to that sort of thing except this, which I found quite by accident; if anyone thinks it's of value I can try adding it when I have time to rewrite it so it's not just a quote.

From 'Veteran and Vintage Motorcycles', by James Sheldon, published in 1961, p. 72: "In France there was... the Bouchet, running on acetylene gas. If it was generated by calcium carbide and water, as seems probable, it may have started the fable of the mysterious rider filling his tank at the village pump."

Interesting to think that this machine might have started the whole running-on-water story... 01:45, 7 March 2014 (UTC)
 * I find it unlikely, as the car in question is really obscure. And there is a difference between an urban legend about someone "filling their tank at the village pump" and the crank wannabe inventors who wish to turn the most familiar and cheap liquid into fuel.--ZooGuard (talk) 15:11, 7 March 2014 (UTC)
 * Perhaps it was a more general misunderstanding involving topping up car radiators and also familiarity steam-powered traction engines - which were then misunderstood (try and describe a typewriter to someone of a younger generation without actually having an example to hand). Anna Livia (talk) 09:49, 29 August 2017 (UTC)

Aluminium-Water
My first edit in… 860 days? Ok…

It is thermodynamically possible to use water as an oxidizer with aluminium fuel to power an engine, producing hydrogen and aluminium oxide exhaust, although it is typically difficult to start this reaction in the first place, as aluminium is usually covered in an oxide layer that only disintegrates with extreme heat. This is the principle behind the ALICE (ALuminium-ICE) propellant mixture currently in development for rockets. Theoretically, one could make a car powered by water and aluminum each stored onboard, but the properties of the compounds and nature of the reaction is so different from that in a regular petrol engine I don't think it would even be possible to modify one to work with it—a completely new engine would probably have to be created. The lower specific energy density (15.5 MJ/kg compared to 42 MJ/kg, AFAIK) combined with the requirement to store both fuel and oxidizer would give it a pretty terrible brake-specific fuel consumption.

All is not lost, however. Aluminium burns at a much higher temperature than petroleum (hence why it is used as an additive to increase the performance of solid rockets), so a greater thermal efficiency could be achievable than with a petrol (or even Diesel) engine. Also, we are blessed with an oxygen-rich atmosphere, so the hydrogen exhaust could be burnt in a sort of afterburner to produce water exhaust and additional energy.

An aluminium-water boat or submarine may be far more practical, as the "water-breathing" engines could work independently of air and use the surrounding water as a source of oxidizer. Aluminium-water turbojets could aid in reaching far faster speeds than traditional ship propellers, just as air-breathing turbojets did for aircraft propellers.

Although slightly off topic, aluminum can also react exothermically with carbon dioxide, presumably producing carbon and aluminium oxide dust as exhaust, so although it would take massive efforts to make sure it would get enough air, a specially-designed internal combustion car could drive on Mars.

Should any of this be covered in the article?

Grant Exploit (talk) 02:40, 3 April 2018 (UTC)
 * Looks like it would fit, as I don't think it would be able to stand alone as its own page. 02:44, 3 April 2018 (UTC)

Description, First Sentence
It's not entirely clear what "Water is fully oxidized hydrogen in a low energy state" actually means, and the statement appears to be of dubious importance. If somebody else understands what it means and can clarify, though, that might be better than removing it; I just don't think it should remain as it is.--35.2.239.194 (talk) 00:10, 15 December 2019 (UTC)
 * The statement is apparently false, regardless of interpretation. The hydrogen atoms in water have an oxidation state of +1, as in the vast majority of compounds, and water isn't just hydrogen. I will remove the statement.--Omicron (talk) 16:29, 15 December 2019 (UTC)