An RC Car That Runs On Soda Can Rings 135
polyp2000 writes with an Engadget excerpt to inspire instant toy envy: "A pair of Spanish engineers have recently unveiled the dAlH2Orean (see what they did there?), a R/C car that runs on aluminum. Dropping a few soda can tabs into a tank of sodium hydroxide produces enough hydrogen to power the little speedster for 40 minutes — at almost 20mph."
Headline: Bad Student Work Gets Tons of Publicity (Score:5, Insightful)
This happens much, much too often on Slashdot.
Aluminum takes a terrible lot of energy to refine from ore. The one good thing about that is that it's really easily recycled, so those aluminum cans sometimes get to be part of something again. But when you dissolve it in draino, and then, inevitably, dispose of the result in your landfill or sewer, you lose all of that energy and make some nasty pollution. What you get back in energy isn't a tiny fraction of what went in.
But they got a patent. Because the patent office doesn't care if your work is good, only that it's original. So, a lot of ignorant people will be impressed by their "innovation".
This would have been cool for a high-school science-fair project. Much too much bad science runs here.
Lye (Score:4, Insightful)
Re:Headline: Bad Student Work Gets Tons of Publici (Score:4, Insightful)
Sure. Let's all do this. Let's power up our cars by improvised H2 generators using discarded aluminum cans. Ignore practical considerations such as: does the average household generate enough alumionum waste to cover its energy requirements, prioce and safe handling of sodium hydroxide, disposal of aluminum sodium oxide etc.
Fast forward 1 year. Most people who had started using the aluminum powered cars have abandoned the system.
Why? Not enough waste aluminum generated by the household.
Why? The price of canned soda has skyrocketed.
Why? The deposit on cans has suddenly gone up from 5-10cents per can to %1.50 per can
Why? Canners can't get cheap aluminum anymore
Why? Aluminum doesn't get recycled anymore because it gets burned instead. So canners need to buy "new" aluminum, which costs a lot more. Why? It takes a lot of electricity to refine from ore.
Re:Interesting... (Score:5, Insightful)
Extracting aluminum from aluminum hydroxide is the standard method (the Bayer process [wikipedia.org]) for refining aluminum from bauxite.
Re:Headline: Bad Student Work Gets Tons of Publici (Score:4, Insightful)
Re:Interesting... (Score:4, Insightful)
Err.. that will be the Bayer process followed by the Hall–Héroult [wikipedia.org] process.
Hall–Héroult process is the one where a vast amount of electrical energy is used to extract the Metallic Aluminium from the Alumina that is the end product of the Bayer process.. Typically plants doing this have their own power station (often Hydroelectric.. but Nuclear is used too) due to the energy required.
Not really very green huh.. it just displaces where the energy is input by several chemical steps.. The energy poured into making aluminium, is basically being extracted later on.
Essentially the Aluminium is being used like a battery.. not a fuel.