Compressed Natural Gas

I've been thinking about converting my JK over to CNG. Doing some research and It's absolutely feasable and cheaper than gas...

Anyone know of someone running CNG currently?

I've driven vehicles that ran on propane. I don't think it would be any different. You loose some fuel economy due to less horse power. It just doesn't burn the same, I don't know if it's a slower burn rate or what. It's cleaner "green"

In the mid 90s, a company I worked for converted several pick-ups with cng. All of them were converted back. At that time the tanks would take up almost 1/3 of the bed. That was almost enough fuel to get from San Antonio to Austin. The range sucked. Unless they came up with a way to carry it in a liquid form, it is not really feasible, especially for the amount of ground you cover. The tank would take up the whole rear of your JK (with the 2nd row folded) and you would have enough to make it to SA(maybe). Then you have to find a place to fill up.

That being said, I would be more inclined to go to propane (and propane accessories, thank you Hank Hill) which is easier to find and has already common dot approved containers .


Screw all of that.....GO DIESEL!

potlickinpirate wrote:

Screw all of that.....GO DIESEL!

X1000, I would jump all over a good diesel conversion kit

Ok. Here's what I know already...

Liquid CNG (LNG) isn't possible, as CNG doesn't get to liquid form till it hits about -200 deg. Would be nice though, since LNG has around 1/600th of the volume of CNG, one would be able to carry enough to drive agross country several times without a fill-up.

Unlike some of the old Propane (a bi-product of CNG refinement) setups, The newer systems are more like "multi-fuel" setups. meaning you can switch back and forth from gasoline to CNG.

Theres about a 10% power loss with CNG, but with the ability to flip a switch and run regular gasoline on the trail and such, I can live with that.

The tank that one company is claiming will give a Dodge Durango 200+ mile range is about the size of the old TJ fuel tanks. I do know quite a bit about natural gas, and from what I'm seeing, the newer tanks are designed to take advantage of whats known as "supercompressability" (baisically putting 10 pounds of shit in a 5 pound sac.)

On the afore mentioned Durango, it cost about $3.17 to fill... thats $3.17 to be able to drive 200 miles...

There are a few filling stations scattered about. One being in CC and several in Houston, and a couple in Shreveport

I'm thinking that IF all the claims are true, I could install this system in my JK, and have a theoretical range of 400+ miles from both tanks. The CNG tank could be mounted where my stock mufler was and then be protected with a skid plate.

I dont give a shit about being "GREEN". I would, however, REALLY like to be able to fill my vehicle with a fuel produced right here in the U.S. I'm tired of lining the pockets of the Sheiks of the UAE and OPEC.

hmmm supercompressability....that would be like the amount of bs I can put on a forum....

cng is very similar to lpg and is very good for the ic engine. The horsepower loss would be negligible.

I know you are the natural gas guy. that's why I stirred the pot....

potlickinpirate wrote:

hmmm supercompressability....that would be like the amount of bs I can put on a forum....

cng is very similar to lpg and is very good for the ic engine. The horsepower loss would be negligible.

I know you are the natural gas guy. that's why I stirred the pot....

You? Stirring the pot???!!! NO!

Hey, I have an idea. Is there a methane conversion kit available. I know there are times when I feel like I could provide a fully human-powered vehicle.

Now that's stirring the pot right there!

I was just thinking of converting my jeep to CNG or even propane yesterday after seeing on the news that some company is running a few vehicles on CNS.

If it isn't too expensive to do the conversion I might consider it,\.

Diesel conversion and then run on vegetable oil...I'd always be hungry!

Ok natural gas guy, I have worked extensively on propane systems (as you know). The lpg systems are exactly that, liquid. 5gal. propane = 5 gal. gas. Cng is still a gas, how can you get the volume without converting it to a liquid? That was the problem before, and I believe it still exists or the tree huggers would have all using it. In a nutshell, if you have 2 cubic feet of cng it does not equal 2 cubic feet of good ole petrol. The problem was range. If they come up with a reasonable way to carry liquuid natural gas..... Then it would be viable.

The car companys would be all over this if it was decent. That is another reason I am arguing....


Have a nice day!

The answer my friend is... Compression.... 2 cubic feet of CNG at 3000 psi is NOT equal to 2 cubic feet of LPG or Gasoline. Liqiuds cannot be compressed, it is a physical impossiblity, however, Gasses can. Therefore, 2 cubic feet of CNG at 3000 psi will have an approximate range equal to 10-15 gallons of gasoline, depending on the application. Like I said, putting 5 pounds of stuff into a 3 pound bag.

RANGE:
The numbers I've found state that one can drive 200 miles on CNG In a tank about the size of a TJ fuel tan, then switch to gasoline and go another 250... thats 450 miles without stopping. 200 of those miles cost ~$4.00 and the other 250 cost ~$50.00

The kit itself cost aprox. $4000.00

There may be a lot of reasons why car companies aren't doing this. I know Ford HAS built quite a few of their 3/4 tons with CNG engines. there are MANY consumer vehicles in the UK and Europe running on CNG and LP now. It also seems that when you mention to Americans that it involves some power loss, there's an immediate choking reaction (as if you tried to get them to breathe water) and a revulsion to the fact that it may be a necessary evil.

Like I stated before, I dont really give a rats ass about "going green" or saving the ozone layer. I personally think thats all crap. What I DO care about is that I'm damn tired of paying foreign countries for oil when I don't necessarily have to.

LIQUID CONVERSION:
While there are methods of cooling CNG to LNG and keeping it there for transport, and I'm certain that it may be a viable solution in a few years, I don't believe that it would be safe for everything that a Jeep is exposed to.

Propane is really close to natural gas...it is stored as a motor fuel in the liquid state. Which can-not be compressed (you are correct). 2 cubic feet of lp will go further than 2 cf of cng. That is the point I am trying to make. Propane is fairly close to gasoline as far as 2gal. of either will go the same distance. So, in my pea brain, if you had a TJ sized tank, There is no way it will have the range of liquid. The shape is also a factor. In essence you will have a cylinder, correct? The volume will be much less because of trying to put a round peg in a square hole (flat tank).

Unless I am wrong (my wife says I am all of the time) about the btus of propane and cng being similar....the sack needs to have liquid in it.

Ok. If there is a 20 cubic foot air tank with no pressure on it, just atmosphere, is there 20 cubic feet of air in it?

Yes......if you pressurize it until it is liquid oxygen then you can-not get any more in it....

You dont get liquid from pressure and you know that. stop instigating!

With just atmospheric pressure on it you cant do anything with it. BUT, it it were pressurized by adding MORE AIR to the tank to say 3000 psi, you could could have power an air tool for a while... AND there would be MORE than the 20 cubic inches of air that the tank holds at nominal.

Cmon Randy, I didnt mean to hurt your feelings... I'm sorry

Correct me if I'm wrong but I think ya are forgetting the density factor. liquid has density, that is where your "more power, mileage" come from. If you could carry NG at it's liquid state and get the density you would get the power and mileage of petro. That's why CNG will never compare.

You are both wrong and right...

NG in liquid state is at -200 deg F. so it wouldn't burn. you could burn the vapors, much like Propane, but it would be more tedious and the needed equipment would be complicated and space consuming.

You are correct that the equivalent amount of Gasoline does contain a higher BTU value vs. CNG. about 10% higher. Thats why it has to be a dual fuel setup for me to consider the conversion. That way I can still wheel on gasoline. It's not a perfect substitute, but in my mind, it is a viable alternative on the highway.

GULF COAST PIRATE wrote:

there are MANY consumer vehicles in the UK and Europe running on CNG and LP now.

Can you name 4 and link to their product page on the manufacturer's website? On my varoius trips to the UK especially (and once to France) I've never seen any place to fill up on either, nor had anyone ever mention such a thing. I don't think even the busses and such run on it. They're a lot less retarded with the diesel-hating over there (too many soccer moms here think, "Diesel? That's dirty!"), so those are FAR more prevalent, but CNG or LP? Not certain about that.

The Volvo V70, F30, and about 5 other models, Mercedes sprinter NGT, Vauxhall Astra van 1.4, Smart Car, Honda Civic GX, Mercedes Benz B 170 NGT, Volkswagon Touran EcoFuel.... There's more. As far as links, copy, paste and google.

Here's the link on the Mercedes: http://www.greencar.com/articles/2009-mercedes-benz-b-series-runs-natural-gas.php

and the Volkswagon: http://www.greencar.com/articles/volkswagen-touran-ecofuel-natural-gas-car.php

BTW, not in the UK, but all of the public transportation in Shreveport LA are now CNG.

Isn't it the same with petro? You're not burning the liquid, your burning the vapor that is given off (fumes) as the liquid turns to "steam". I have to go elementary school to understand

So what kind of equipment are talking about to carry the same amount of liquid NG as petro? I mean we (AC companies not us) carry freon in liquid form that is already boiling inside the container. I know freon is not explosive (I think) but isn't already at, like -200 degrees?

Deacon wrote:

GULF COAST PIRATE wrote:

there are MANY consumer vehicles in the UK and Europe running on CNG and LP now.

Can you name 4 and link to their product page on the manufacturer's website? On my varoius trips to the UK especially (and once to France) I've never seen any place to fill up on either, nor had anyone ever mention such a thing. I don't think even the busses and such run on it. They're a lot less retarded with the diesel-hating over there (too many soccer moms here think, "Diesel? That's dirty!"), so those are FAR more prevalent, but CNG or LP? Not certain about that.

Research LPG gas in Holland or Germany. I know back home a lot of vehicles run on LP gas.
Every gas station (Read 95%) has a special pump just for LPG.

The gas itself is real cheap back home, and then they tax the crap out of it. However it still is cheaper then regular gas.
THe LPG and I assume Natural gas, comes in liquid form and the gasses coming from that is what your engine runs off of.

The tanks we had in the trunk of our vehicles were about half the size of the trunk space, I forgot how many liters. It is less fuel efficient then regular gas, but is is also a lot cheaper.
You basically would be spending more time at the gas station filling up.

If you ever ran out of LPG, you can just flip the switch and run on regular gas.

GULF COAST PIRATE wrote:

The Volvo V70, F30, and about 5 other models, Mercedes sprinter NGT, Vauxhall Astra van 1.4, Smart Car, Honda Civic GX, Mercedes Benz B 170 NGT, Volkswagon Touran EcoFuel.... There's more. As far as links, copy, paste and google.

Care to share any links to actual manufacturer websites, hopefully showing the CNG option, not old "Green Car" links about interesting plans that never come to fruition? I can't find anything about it on Mercedes' UK site, for instance. Only gasoline and diesel options.

LP is still interesting to me is still very interesting from a crawler buggy standpoint. But then refueling is kind of a different question