LNG and LPG as personal vehicle fuel?

[Studioguy]

Sorry if this isn't the right place to post this question (forum or specific board), but I was hoping some of the big-brains here could pass along some of their wisdom to a dufus like me.

My question is whether natural gas or propane gas would really be a viable energy for personal vehicles in the United States? My father had his personal truck converted to propane back in the 80's and it seemed like a cool system. It seems like today the only vehicles that are setup to run on propane or natural gas are government or fleet vehicles. If it's good enough for that, is there a reason it wouldn't work for the masses?

I'm not asking for political purposes or for any sort of political explanation, although I suspect there are a few of them. I'm simply wondering if there's a supply, processing, or distribution related reason that we couldn't possibly work.

[slang]

LPG is a regular fuel used for personal vehicles here. But ... it's taxed more than petrol and diesel, so you have to do some calculations to see how it works out. Price of gas installation in car, extra tax, amount saved per kilometer, amount of kilometers per year, etc. So it depends on how much you drive per year, here. Silly since LPG is said to be a much cleaner fuel.

[LotusExcelle]

LPG is used here in the states from time to time. Not really on personal vehicles but more for work vehicles. It is also used, or was used, as a kind of nitro for diesels kind of thing.

The problem is that when you convert over a regular gas motor to LPG you lose a considerable amount of power and efficiency. It may cost less but it works out to being quite similar in price if you consider how often you have to refuel and the performance losses.

[Stuart van Onselen]

I would guess that fleet vehicles use it more often because they can refuel at the depot. Personal transportation (in most of the world) will be stuck in the Catch-22 of not having enough filling stations, because there aren't enough cars that need LPG filling stations...

[EricM407]

What if you use natural gas? Most people (at least here) have natural gas piped to their house. So what do you need to get the pressure up enough to fill the tank in the car?

About ten years ago Ford was selling natural gas pickups (mostly to fleets, I guess), which they build at a plant here. They had an arrangement where the local gas utility would come to your house and install the hardware at no cost if you bought one of these trucks, but I don't know anybody who did it.

[NEOWatcher]

So what do you need to get the pressure up enough to fill the tank in the car?
New gas lines (IIRC)

I heard that even with a pump on the gas lines, the volume is insufficent to fuel a vehicle within a reasonable time. (I think that was somewhere in the overnight range but I cant remember)

So; you'd need bigger pipes, or higher pressure lines. Either way, it forces a change in the mains (in many residential areas).

[Studioguy]

Thanks for the info guys. Around this area, propane is pretty easy to get at any number of places. It wouldn't work too well for powering a car, but you can even buy a filled 3 gallon size container (16.5 pounds I believe) of propane at the grocery store to hook up to your grill for about $14US.

I guess I'm just wondering why the option of using compressed natural gas or liquid propane isn't getting more traction as an alternative to oil based fuels. It was a radio ad by a guy that I'd been told was a nutcase before that reminded me of my dad's truck back 25 years ago running on propane. Since posting this question I had a chance to ask him about that truck and he said the reason he didn't have it done to any other vehicles after he got rid of that one was the fees and taxes the city, state, and federal government threw on it. His recollection was that they added so many requirements to run a vehicle on propane that it ended up costing the same as running gasoline for 3 years before you saw any savings.

I certainly don't want to get into a political debate on it, so I apologize if that seems like the direction. My curiosity isn't really whether it's a tremendous savings over gas but whether its a feasible alternative fuel to keep our cars moving that would satisfy the environmental concerns of some people and the dependency on foreign sources of oil from others. Hank Hill (http://www.imdb.com/title/tt0118375/) would surely think it is!

[JustAFriend]

Lots of cities experimented with LNG for busses and fleet vehicles back in the 70s and 80s after the OPEC embargos.

For municipal vehicles and fleets there is a LOT of experience and I see no problems; but I shudder to think of everyday Joe's being able to tap into the home gas pipes -- just TOO many ways for things to go boom. Gasoline is FAR safer as a fuel.

And it's like any other fuel... there is a finite supply and I suspect that if you yanked a considerable percentage of the vehicles on the market (like Pickens is proposing), the demand would outstrip the supply and the price would go up --- just like gasoline.

TANSTAAFL - There ain't no such thing as a free lunch....

[ravens_cry]

My dad had his old high top camper van converted to propane. There really wasn't a problem except the time we ran out of fuel, as we had to go get tow truck, because one can't just get petrol can full of propane.It did rather restrict which gas stations we went to, but the one we did go to was quite common.

[Ronald Brak]

About 10% of Australian vechiles run off LPG (mostly a mixture of propane and butane). You can buy it at any service station. There are two main advantages to LPG. One, it produces less CO2 and other pollutants than gasoline, and two, we have a lot of LPG and not much oil. (Australia produces enough oil to supply about 63% of it's own needs, but maybe not for much longer.) The government here will pay you $1,000 if you convert your gasoline car to LPG. This is good because it will reduce CO2 emissions, but stupid because LPG rises in price in line with oil and so we're not protected from oil price volitility.

[George]

LNG was mentioned but it seems to be a thing of the past, I think. The liquification cost/handling/storage is, apparently, higher than CNG (compressed natural gas), which is the latest thing. The City of Austin has purchased a million dollar CNG plant and is switching their vehicles to this fuel. San Antonio has just installed a station for their new CNG vehicles that they will be buying soon. T Boone Pickens is pushing CNG constantly with his commercials, but I have yet to see anything in a cost per mile comparison.

Here are some negatives I see but would like someone who knows more to elaborate.

CNG negatives:
> HHV (high heat value) is far less than gas (about 70% to 75% less).
> Storage tank size is far greater and likely will not be enough to match the gas unit travel distance.
> I think the compression is up to 3000 psi or more, so are they a backseat bomb?
[Safety is an issue, yet I haven't heard of problems.]
> Initial cost is high.
> Fueling points are few, which is a compounded problem with shorter trip distances. [This will change with popularity, of course.]
> Pump price is shown in an advertisement as being about 40% or more less than gas, but is this by the equivalent gallon. [Remember that CNG is not liquified, so what does this lower price equate to? I assume a gallon in volume at storage pressure, but maybe not.]


There was a recent bid on street sweepers here in San Antonio. The CNG truck bid was more than $ 80,000 higher than the diesel truck. The diesel truck was about $70,000, so the CNG engine more than doubled the price of the truck! Ouch. The LPG truck was about $ 55,000 higher, IIRC. They are buying the diesels, which is wise. There were no CNG or LPG 2008 midsize trucks (33k lb. GVW) due to the Tier III engine emissions conversions, apparently. However, the 2009 with CNG and LPG can now be ordered, and these alt. fuel engine prices are a little less than I just stated.

Oddly enough, another option has been an LPI conversion unit for trucks. This unit takes a new gas engine and converts it to LPG. This price was only about $ 11,000 more than standard diesel. The City of SA is rejecting all the prior bidders who did not bid CNG or LPG on their large fleet of trucks, and they are going with the one truck dealer (who did not even bid) by using a cooperative program (Texas School Board, likely) in order to take advantage of the savings.

[Ronald Brak]

In Australia is costs from about $1,200 to about $2,720 (US dollars) to convert a car to LPG, but those figures are from a couple of years ago.

[NEOWatcher]

It's also important to seperate the NG and propane discussions in certain contexts.
Propane is derived from oil refining, so any push for propane would just shift the balance of demand for the various components of oil.

[Ronald Brak]

Propane is derived from oil refining, so any push for propane would just shift the balance of demand for the various components of oil.

Some fields, such as in Australia, contain very large amounts of propane, butane, pentane and so on giving LPG that doesn't come from oil. Hence ten percent of our cars run off it. Almost every taxi does due to the lower cost per kilometer (government tax breaks for LPG) and longer engine life.

[NEOWatcher]

Some fields, such as in Australia, contain very large amounts of propane, butane, pentane and so on giving LPG that doesn't come from oil.
Interesting...I never heard that. I have heard that NG is a mix of various compounds, but don't specifically remember propane. Nor, have I heard of anyone separating out the components of NG (on a commercial basis).
But; If I wanted to get nitpicky about it, the propane still needs to be separated and distilled (http://www.wisegeek.com/what-is-the-difference-between-propane-and-natural-gas.htm).

[Ronald Brak]

Nor, have I heard of anyone separating out the components of NG (on a commercial basis).

It's quite normal and done all the time in Australia:

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

Of course, it all depends on the field it comes from. Some gas fields are mostly methane so there is little or no LPG to be had from them and no point in trying to extract it. Others fields are chock full of LPG.

[NEOWatcher]

Of course, it all depends on the field it comes from.
I guess I'm used to hearing about our fields. Around hear (not sure how localized) they pump out the NG directly into the supply mains (with some basic moisture control and odor additives).

[George]

I guess I'm used to hearing about our fields. Around hear (not sure how localized) they pump out the NG directly into the supply mains (with some basic moisture control and odor additives). Yes, that is my understanding, too. Most of the gas wells I am familiar (South and West Texas) are very deep. There are possible exceptions, of course, but 10,000 feet is a rough depth I often hear about as a minimum depth due to the geological column in this region. At that depth, the pressures probably must be reduced to put them in the mains.