Compressed Air Cars

maninthestreet

Sounds like just a load of hot air, if you ask me.

reeac

maninthestreet wrote: »

Sounds like just a load of hot air, if you ask me.

I've just Googled and Wikepedied[?] and found that:

energy stored in compressed air bottle: 40-100 kJ/Kg.
energy stored in diesel fuel: 45MJ/Kg.

so diesel wins by a factor of 1000.

s_b

reeac wrote: »

I've just Googled and Wikepedied[?] and found that:

energy stored in compressed air bottle: 40-100 kJ/Kg.
energy stored in diesel fuel: 45MJ/Kg.

so diesel wins by a factor of 1000.

only if you can find some:D:rotfl:

jaydeeuk1

TrickyWicky wrote: »

Erm no, we get it from tree's that generate oxygen. From fuel, air and a spark we get carbon dioxide and all sorts of other sinful nasty chemicals. Do you work for an oil company or something? Are you fearing for the security of your job? - Fear not, I have an interesting solution..

For these compressed air vehicles, surely with so much CO2 around the planet we could just capture it, compress it and use it to fill these new air powered vehicles air tanks?

Sure, it'll mean the CO2 is pumped back out again but at least its being used, recaptured, re-used, recaptured etc. The capturing part of the process is two fold - it takes it out of the environment and gives the oil companies something positive to do while still making their money - win-win. Of course they'll become so greedy about it that they'll setup huge CO2 capturing farms to catch as much as possible thus cleaning our air and bringing the planet back to its senses. Once the oil companies have these farms setup they'd have the infrastructure in place to capture other nasties that we've released too.

Not quite right, majority of our oxygen doesn't come from trees, but from the ocean (phytoplankton to be exact)

I remember reading about the air car and watching prototype videos some years ago, but they never got the funding they wanted. These air cars also had filters that took all the dust particles out the atmosphere, so the air coming out of the car was cleaner than the air going in.

http://www.mdi.lu/english/entreprises.php

DVardysShadow

Gloomendoom wrote: »

... Reciprocating compressed air engines are like steam engines. The four stroke cycle doesn't apply and would be utterly pointless.

Well, yes ... and ????

Dave_C derived the air shifted by an internal combustion engine. He was out by a factor of 2, because the typical 1 litre car engine is 4 stroke, but he calculated on 2 stroke. So let's get the benchmark right before we do the comparison.

vaio

jaydeeuk1 wrote: »

Not quite right, majority of our oxygen doesn't come from trees, but from the ocean (phytoplankton to be exact)

I remember reading about the air car and watching prototype videos some years ago, but they never got the funding they wanted. These air cars also had filters that took all the dust particles out the atmosphere, so the air coming out of the car was cleaner than the air going in.

http://www.mdi.lu/english/entreprises.php

Don't know about the oxygen but surely on a compressed air car any dust would come from the compressed air and that should have the dust filtered out at the compression stage

Dave_C_2

DVardysShadow wrote: »

Well, yes ... and ????

Dave_C derived the air shifted by an internal combustion engine. He was out by a factor of 2, because the typical 1 litre car engine is 4 stroke, but he calculated on 2 stroke. So let's get the benchmark right before we do the comparison.

You are probably right. It was a crude estimation and any factor of two is swamped amongst the three orders of magnitude quoted by reeac above.

Several points spring to mind:

• As it is expanding gas, the engine and hence the car will get cold. OK in the hot weather but for the other 9 months of the year there is no obvious method of heating the car. Perhaps a small cylinder of combustible gas driving a burner/heater
• There is the need for a small battery to power indicators/ brake lights, engine management system and so on.
• During the hours of darkness headlights are required. This means lugging around a big battery or driving an alternator. Either way this will reduce performance and range
• You could kill two birds with one stone and have a small acetylene tank to power the heater and acetylene headlights.:)

I found this Guardian web page where they confirm the cold engine and the massive range of 65 miles at a heart-stopping 30 mph.
Googling for French compressed air car there are a lot of promises of "on the market soon" and "to be launched" from circa 2009 but nothing has materialised yet. This speaks volumes for the impracticality of an air-powered car.

Dave