Slashdot Mirror
The Car That Makes Its Own Fuel
Spy der Mann writes "A unique system that can produce Hydrogen inside a car using common metals such as Magnesium and Aluminum was recently developed by an Israeli company. The system solves all of the obstacles associated with the manufacturing, transporting and storing of hydrogen to be used in cars. And it's completely emission free."
.other than the fact that the fuel coil will be 3 TIMES THE WEIGHT OF A CONVENTIONAL PETROL TANK.
Anybody want to venture the supply problems of supplying about 100 Lbs of magnesium wire per commuter per week. The article seems to claim it won't cost more than petrol. Petrol is delivered by pipeline or tanker. Pumps and hoses won't deliver the wire. In reality, is there enough of this metal to support a fuel infrastructure?
The truth shall set you free!
> The pollution is shifted to wherever the power to make the metals is produced.
True. But how does it compare with zillions of cars worldwide being started in the morning on full choke? If Al/Mg/Zn/whatever can be produced at a power plant that runs continuously at peak efficiency, then ok it's still polluting but it's better than what we currently have.
One enormous benefit of this approach is that the raw materials are completely recycled. Burn oil, you have no oil left. Convert Mg to MgO and back again and you still have your original Mg.
A completely pollution free solution this is not. But it's an improvement, no?
I deal with organoaluminum reactions all the time, which produce aluminum hydroxides on workup. The colloidal aluminum hydroxide sludge can be treated with sodium hydroxide to convert it to a filterable consistency.
In fact, I think that lithium aluminum hydride (and various other light metal hydrides) has been mentioned as a possible hydrogen storage source. I don't know anything more about it than it's been mentioned (specifically, how they plan to regenerate it, LAH isn't exactly cheap)
Lets just address these in order.
a) yes Al takes a lot of energy to make. we would call this a "high energy density" material. This is a good thing, not a bad thing. It means we can put more energy in a smaller (or lighter) package. Gasoline is not incredbily energy-dense. One way or another you have to put energy into the process of creating fuel. The only difference with petrolium is the energy has already been put in, and it just needs to be processed for us to use easily. Since you have to put energy into it, a source like nuclear power actually makes a great deal of sense. It's highly renewable, low pollution, and provides a very large amount of energy.
b) um, the trucks can be wire-powered too, y'know. It'd be kinda silly for them NOT to be wire powered.
c) Water will add to the weight, yes. I don't know all the physics, but in general I know you can get a LOT of hydrogen out of a little water. A system like this may require occasional refilling. On a guess I'd say you might need to tank up on water every 100 miles or so. The water is after all the source of your hydrogen, the wire is the source of the energy. This also greatly increases the safety of the vehicle, because there is no need for a very high pressure hydrogen tank, and the associated hazards of refilling and transportation of hydrogen.
d) As for efficiency, there is always heat. Since the system uses heat to crack the water, it's not going to be too far off in efficiency from a regular car. It actually may be less efficient, since there are two heat losses - you have to burn the hydrogen after all, and that too releases heat. This may not matter as much since the fuel source is more easily renewable.
e) it's an interesting system when you examine it. You are using a wire to generate heat, to turn water into oxygen and hydrogen, and then BURNING that hydrogen (presumably with the oxygen you make, to improve efficiency) and that actually gets you... water. I suppose technically it may not need water refils because of this. But then if you look at that, you've come full circle. The only addition has been the wire being turned into physical motion. It's too bad they need to go through the water-to hydrogen-to water conversion but it provides a buffer that allows for fast accelleration etc. Considering the zero emissions and loss of reliance on fossil fuels, it sounds like a very good move, environmentally.
I work for the Department of Redundancy Department.
It would be a good thing if it were true. The massive ammounts of energy used to reduce bauxite are mostly lost as waste heat. If they were actually stored in the material, this might be an efficient system to transport energy.
Actually, this is true. Thermite is a substance that burns at around 5000 degrees, and is capable of welding metal plates and destroying metal machinery. I've always wanted to see someone put a thermite grenade on top of one of those really big soda machines and watch it explode.
Thermite is a mixture of aluminum shavings and rust. The heat is produced by the oxidation of the aluminum as oxygen is transfered from the rust. There's a car in the St. Louis Science Center that is entirely powered from that reaction. It's an experimental thing and I've never heard about why it wasn't practical, but I know it works.
Haraldm is, in fact, correct in that they're just moving the energy production back to a central power plant, and the efficiency of the process is in question. Until they figure out how to turn bauxite into aluminum in solar furnaces, I'd say that this solution is not terribly effectual.
In response to the "where do they get the water?" comment, distilleries figured out how to condense fluids from gasses centuries ago. Properly designed heat exchangers and condenser coils should notably limit the loss in that direction.
All things said and done, either this isn't a complete idea, or they're hiding the rest of it because they think they're clever. It's certainly not a NEW idea, it's just feeding off the hype of "hydrogen fuel!", and propogating because people don't understand the thermodynamics of the process.
Wake up - the future is arriving faster than you think.