Alternative Fuels

I attended an alt fuel conference a couple of weeks ago in Austin, Texas. Strangely, most of the interest has shifted back to CNG (ignoring the ever present gimmick folks with fuel line magnets etc, plus the electric crowds). I had an opportunity to meet with a couple of the CNG vehicle developers, and folks, the aftermarket industry has a long way to go to catch up with these offerings!

One company has a 2008 CNG Impala that just received EPA certification (a major step for sales) that runs identical to an OEM gasoline vehicle and is totally driver transparent in operation. Underhood components are almost non existent. The only LPG showing was the Liquid Propane Fuel Injection offered by CleanFuelsUSA through Bluebird and select Rush distributorships. At this time, there are few light vehicle offerings on LPG with the exception of some of those provided through a few conversion firms, but technology comparison is not at the same level as CNG.

CNG has the marketing dollars from the utilities and venture capitalists and some technology advantages. The largest drawback to more widespread CNG use is the lack of on the road fuel availability.
LPG has the advantage of wide fuel availability but not that much funding with a few technology bumps.

Franz

As you know Franz, NZ in the 80s had an extenive netwrok of automotive CNG at the pump.
Today I do not know of a single automotive filling station.
I ran 2 of my cars, including the Camaro on CNG, both with IMPCO technology
Advantages:
1/Bloody cheap to run compared to LPG and Petrol.

Disadvantages:
1/Range, a little over 1/2 of what the same sized lpg tank will give.
2/The CNG tank is very heavy, modern lighter cars would also need stiffer suspension.
3/LPG on a standard petrol engine sees little or no power loss, CNG thu has potentual for much more power, requires serious rebuild (compressions, cams etc) to recover this loss.
4/ Fuel lines fittings require much higher pressure requiremnts over LPG lines.
5/Tanks/lines are far more expensive than the LPG equivilents.

i thought the tanks were spun alum with fiber glass? and stainless lines. PG&E was really big on this for a while.

There are four basic styles of CNG tanks, and are listed as to their type:

Type 1: Hydroformed or forged steel, resembling oxygen cylinders. These are typically very heavy but are the oldest types around, and the least expensive.
Type 2: These are either steel or aluminum with a hoop wrapped overlining. Hoop wrapping means that the composite wrap is spun around the tank perpendicular to the tank centerline. The wrapping does not extend over the end spheres.
Type 3: This tank uses an aluminum inner liner that contains the product but has relatively little strength by itself. It has a full spiral wrapping all over the tank.
Type 4: This tank uses a poly or other non metallic inner liner that only contains the product. There is no inherent strength. It also has full wrapping all over the tank.

These tanks vary in prices and sizes. The most popular is the Type 3, while if weight is an issue, Type 4 is used. Stainless steel fuel lines and fittings are required by law in the US and Canada, but in other parts of the world, steel is allowed (even brake line tubing!)

Franz