Alternative fuels

[Pure]

sound promising?

lots of r and d went into this:

http://en.wikipedia.org/wiki/Tesla_Roadster

paper discusssing its battery system:
http://www.teslamotors.com/display_data/TeslaRoadsterBatterySystem.pdf

 

[Weird Harold]

lots of r and d went into this:

http://en.wikipedia.org/wiki/Tesla_Roadster

paper discusssing its battery system:
http://www.teslamotors.com/display_data/TeslaRoadsterBatterySystem.pdf

The Tesla Roadster is definitely drool-worthy from both an appearance and performance aspect, but I just don't see it catching on with soccer moms -- or just moms in general. I suppose you could buckle a car seat in on the passenger side but they're not very safe in front buckets.

Part of what makes the Tesla's performance so good is that it's very light-weight and that doesn't scale up to sedans, station wagons or SUVs.

 

[R. Richard]

Octane isn't a rating of energy content, but I see your point. Any engine can be optimized to get the most out of any specific fuel but does so at the expense of air quality and flexibility.

The majority of cars sold in the US are designed to run on 87 Octane, not because 87 Octane is a better or more efficient fuel, but because higher compression Engines that need higher octanes produce more NOx compounds that turn into Smog and Acid Rain.

Propane is a cleaner burning fuel than gasoline under equivalent conditions, but when you put nitrogen and oxygen together under high pressure and high heat, you NOx-ious compounds whatever you're burning to generate the Heat.

FWIW, Diesel engines can also be converted to Propane/Compressed Natureal Gas/Methane (but the conversion is more expensive and extensive than for gasoline) and they already have the high compression to use the potential.

Note the ratio of NOx for gasoline and propane. Yes, higher compression will produce a bit more NOx, but propane starts out with an almost 12 to one advantage. An engine fueled with GOOD propane will produce a lot less pollutants than an engine fueled with commercial gasoline.

Emission of Nitrogen Oxides - NOx - when burning common fuels are indicated in the table below:

Fuel Emission of NOx 1)
(g/kg fuel)
Oil 3.0
Kerosene 3.0
Coal 4.5
Propane 2.3
Gasoline 27 3)
Hydrogen 0 2)
Natural Gas 1.0
Butane 2.3
Wood, Birch 20% moisture content 0.7
1) note that the emission varies widely depending on application temperatures and air/fuel ratios. In general - higher combustion temperature and higher air/fuel ratios increases NOx emissions.

2) zero emission for hydrogen is a theoretically value. In practice hydrogen burned in air produces more NOx than natural gas due to the high flame speed

3) catalytic systems common on most modern vehicles reduces NOx

NOx emissions contributes to eutrophication, acidification and the formation of ground-level ozone.

 

[DesertPirate]

The Tesla Roadster is definitely drool-worthy from both an appearance and performance aspect, but I just don't see it catching on with soccer moms -- or just moms in general. I suppose you could buckle a car seat in on the passenger side but they're not very safe in front buckets.

Part of what makes the Tesla's performance so good is that it's very light-weight and that doesn't scale up to sedans, station wagons or SUVs.

Putting a car seat in the front is against the law in most states for that very reason.

 

[Weird Harold]

Putting a car seat in the front is against the law in most states for that very reason.

But, if you only have two seats, are they Front Seats or Back Seats according to the Law?

Doesn't that make it effectively illegal to transport a child under 40 pounds and 48 inches in a sports-car?

 

[Weird Harold]

Propane 2.3
Gasoline 27 3)
Hydrogen 0 2)
Natural Gas 1.0
Butane/propane 2.3

2) zero emission for hydrogen is a theoretically value. In practice hydrogen burned in air produces more NOx than natural gas due to the high flame speed

From your chart, it would appear that Compressed Natural Gas would be a better -- and more widely available (in theory) -- choice for eco-friendlyness.

Hydrogen is probably the best choice in the long run because it completely eliminates CO2 emissions but the two words H-Bomb and Hindenburg put unrealistic restrictions on generating, handling and storing compressed H2 gas. (and any existing gasoline engine can run on H2, although not quite as well as with Propane, Natural Gas or Methane; it requires more retuning than the hydrocarbon gases.