manchild wrote:I know that but as it was mentioned as "green" fuel for powerplants I wrote that it isn't so.
You are right: coal hardly qualifies as green. But it is cleaner than other alternatives, like gasoline or hydrogen. This is the reason why we are going to move to diesel: it contaminates but it is cleaner than gasoline. Diesel produces more particles of carbon, wich cause dirt (on your clothes, on the sidewalk) but less nitric oxides, which cause smog (in your lungs).
Hydrogen, as of today, is made by reduction of carbon with sulphuric acid (or something like that, please check, I hate chemistry) with the consequences you can imagine: you use oil or coal (carbon) AND sulphuric or whatever-ic acid. Nice.
Actually, the cleaner energy source is nuclear (let cry whoever wants to cry), even if after Chernobyl "the going got though", but I guess you will kill me if I open a post on a nuclear-engine F1.
This is why proposing to extract thorium from coal is going to give you a "tin-foil hat award" at least (and maybe an American attack...
), being a good idea as it is. I haven't dared to talk about the Miller-cycle engine, for example, the quasiturbine already discused in this forum, the Stirling engine or, if we let our imagination fly, the moving walkways of Asimov's "Caves of Steel". I used to joke that transportation engineering has a clear goal, like no other profession: the Enterprise "teletransporter" of fame, but I don't do it anymore: this has contributed to a fame of "trekkie" I do not deserve.
There is also the effect of concentration: it seems more difficult to pick up emissions at moving cars than at a central smokestack in a coal plant, as the idea of Washington University's liquid nitrogen car shows.
"Like the old and well known joke goes": what we are seeing here are people that want to position themselves as "greens" but all they want is "green$". This is why market forces are not enough, I guess.
As for the efficiency of the electric engine and the batteries, sometimes is easy to forget the losses in generation and transmission of electricity, which is why the compressed air could compete (as long as the pumps don't use electricity, I presume). My evil colombian mind tells me that this is why the seller carefully phrases this: "you will fill your car at a central station AND IF YOU WISH you will fill the car at your house with an electric pump". I suppose they let for your imagination (and wishes) to figure out the size of your electric bill ...
The tanks for the aircar are made of carbon fiber, like the monocoques, so this is what they say when you talk about the
kablaam mentioned by joseff. The GM flywheel car was aborted when one technician died during research and several flywheel cases exploded, so I do not know if they took this time this issue more seriously. I would say that a couple of glasses of "Tank-eray" gin are more dangerous than one of these tanks, if we believe statistics.
Do not swallow the talk of the seller, of course: the lesson here is to consider the entire chain, from creation to disposal, like they teach you at systems engineering. It is somethin' zen-like: feel the system, be the system.
Normally there are no magic bullets in engineering. The surefire way of today is the obsolete technique of tomorrow and every time you tighten a bolt, another gasket, far away, moves.
Be the gasket.
But do not forget that in the real world, you have the additional problem that your opponents are normally busy kicking all the bolts and gaskets in your machine...