Propane versus Gasoline

[DanTrentfield]

They're both hydrocarbons, they're both nasty, which is more sustainable, economical, environmentally friendly, and efficient? Lets look at some chemistry below

 

Propane's chemical structure is C₃H_8, it has less carbon than gasoline whom's chemical structure is 2C₈H₁₈ and therefore produces less Co₂ with a 5o₂ reaction.

 

Propane gas isn't very powerful when it comes to combustion, although it produces more heat than gasoline, it isn't as explosive under pressure and you need more of it to have an explosive reaction

 

Propane is wayyyyy cheaper than gasoline, as the average price of gasoline is $1.80/gal, versus the average price of propane is $0.02/gal. (Gaseous form)

 

Propane can be stored more efficiently than gasoline as it can be compressed into LP at around 28-140psi.

 

Propane engines consume around 5-7 times more fuel than gasoline engines.

 

Propane can be found as a by-product of refining natural gas.

 

Propane engines' performance is significantly lower than gasoline engines' performance.

 

Overall tally Propane 4 Gasoline 3, Statistics: Propane produces 15/16th's of the Co₂ that gasoline produces, Propane is ~900% cheaper with consumption factored in, Propane is a renewable resource as it is a by product of refining natural gas, Although your engine will be more expensive, it's cheaper in the long run, and although you lose performance, you save $1,872 a year if you fill up your 20 gallon tank weekly.

Edited February 17, 2016 by DanTrentfield

[Phi for All]

Propane is wayyyyy cheaper than gasoline, as the average price of gasoline is $1.80/gal, versus the average price of propane is $0.02/gal.

 

Or not.

[DanTrentfield]

 

Or not.

That's for LP, we're talking gaseous propane. But you're right, LP is expensive as heck.

Edited February 17, 2016 by DanTrentfield

[John Cuthber]

If you want to compare prices you should probably do it on a per kilogram basis (or better yet a per Joule, or per mile basis).

None of that matters since much of the price of gasoline is tax. If people started using propane instead then the government would tax propane instead.

Edited February 17, 2016 by John Cuthber

[DanTrentfield]

If you want to compare prices you should probably do it on a per kilogram basis (or better yet a per Joule basis).

None of that matters since much of the price of gasoline is tax. If people started using propane instead then the government would tax propane instead.

Forgot to factor that in...... stupid taxes..... Anyways, economically speaking wouldn't worldwide market demand drive up value to narry a few cents shy of what it is?

[Phi for All]

That's for LP, we're talking gaseous propane.

 

How did you avoid the dimensional analysis errors using US gallons as a measurement of a gaseous substance?

[DanTrentfield]

 

How did you avoid the dimensional analysis errors using US gallons as a measurement of a gaseous substance?

I used firstly the proper units to measure gas (ft³) and then converted over into gallons³ and did the 3rd root of gal³. Then using BTU's I calculated heat energy and cost/gal.

[Moontanman]

liquid propane is the fuel of choice for indoor machinery like forklifts, it's exhaust isn't quite as unpleasant as gasoline engines. When I worked for DuPont we had all kinds of vehicles running on the stuff from trucks to front end loaders. I am curious as to how you would plan to store gaseous propane dense enough to carry enough with your vehicle to give it equal miles per gallon to liquid gasoline.

 

I am not following your logic on this at all, you said you were talking about propane not LP but then you talk of compressing it into LP. Why would it be better to buy it as a gas then pressurise it into a liquid?

 

Why not use natural gas compressed into a liquid? By definition there should be much more methane available if propane is just a by product of natural gas.

 

Some cars are already made to use natural gas and sell a kit that comes with the natural gas car to pressurize the methane from a your residential source which is piped in as a low pressure gas..

[DanTrentfield]

liquid propane is the fuel of choice for indoor machinery like forklifts, it's exhaust isn't quite as unpleasant as gasoline engines. When I worked for DuPont we had all kinds of vehicles running on the stuff from trucks to front end loaders. I am curious as to how you would plan to store gaseous propane dense enough to carry enough with your vehicle to give it equal miles per gallon to liquid gasoline.

 

I am not following your logic on this at all, you said you were talking about propane not LP but then you talk of compressing it into LP. Why would it be better to buy it as a gas then pressurise it into a liquid?

 

Why not use natural gas compressed into a liquid? By definition there should be much more methane available if propane is just a by product of natural gas.

 

Some cars are already made to use natural gas and sell a kit that comes with the natural gas car to pressurize the methane from a your residential source which is piped in as a low pressure gas..

True, but the reason why I was talking about LP (which I forgot to hint at) was that we could store propane as LP, and then use a thermal exchange unit to cause it to boil and turn into gas, then feed it into a combustion chamber with a concentration of oxygen, and spark it.)

True, but the reason why I was talking about LP (which I forgot to hint at) was that we could store propane as LP, and then use a thermal exchange unit to cause it to boil and turn into gas, then feed it into a combustion chamber with a concentration of oxygen, and spark it.)

Adds complexity, but brings up mileage per tank A LOT.

[Moontanman]

True, but the reason why I was talking about LP (which I forgot to hint at) was that we could store propane as LP, and then use a thermal exchange unit to cause it to boil and turn into gas, then feed it into a combustion chamber with a concentration of oxygen, and spark it.)

Adds complexity, but brings up mileage per tank A LOT.

 

 

I'd like to see how your arrived at the idea that in current vehicles propane is burned as a liquid, it is not, no heat exchanger is necessary, you just us the gas as it boils in the storage tank when pressure is reduced..

[Phi for All]

True, but the reason why I was talking about LP (which I forgot to hint at) was that we could store propane as LP, and then use a thermal exchange unit to cause it to boil and turn into gas, then feed it into a combustion chamber with a concentration of oxygen, and spark it.)

 

This is how it already works. Both LPG and gasoline don't burn the liquid, they burn the fumes (gaseous). The liquid form doesn't aid combustion, but is used for a much more efficient storage medium.

[swansont]

How did you avoid the dimensional analysis errors using US gallons as a measurement of a gaseous substance?

I used firstly the proper units to measure gas (ft³) and then converted over into gallons³ and did the 3rd root of gal³. Then using BTU's I calculated heat energy and cost/gal.

Um, what? A gallon is a measure of volume. 1 cubic foot is about 7.5 gallons [uS, liquid]

[John Cuthber]

Comments made the thread here

http://www.scienceforums.net/topic/93578-viability-of-a-gaseous-propane-powered-engine/?p=906707

also apply to this one