I actually have done a lot with fuels. I've done experiments with fuels using a pulsejet engine. I had a simple thrust measuring setup and used gasoline vs. diesel. Diesel made more thrust since it had more energy in it. This is obvious. I've done a lot of research and have done a fair amount number crunching and stoichometry. What you don't seem to understand is that alcohol fuels are more complex because of the attached oxygen.

This isn't a quote, it is a FACT OF SCIENCE.
Ethanol is 34.7% OXYGEN by mass

That's a very large percentage of liquid oxygen. It takes up a negligible volume so it's pretty much free oxygen. Air (air contains oxygen btw (~20%)) is the limiting factor of an engine as i have stated before. The "free oxygen" in ethanol more than makes up for its low energy.




V8 Kila has backed it up with numbers too.

 

Anything that grows 'can convert into oil'
Company finds natural solution that turns plants into gasoline
http://www.worldnetdaily.com/index.p...w&pageId=59402

This isn't exactly about Ethanol, but it is about producing alternate fuels from plant materials.

 

V8Kila has a turbo!!!!

On a turbo engine it's very easy to make more power on ethanol than gasoline due in part to it's higher octane and better latent heat of evaporation properties. You can run more boost and more aggressive timing. However mileage will never go up. Far from it. You always need more fuel. Looking at only power numbers on a forced inducted car isn't telling you the whole story. It's not telling you why it is the way it is.

Also get over the oxygen by mass argument. Kindly remove it if you want to discount it so we can do an equal comparison under your own terms. I'll wait. By your own admission ethanol is less efficient. Here's what you said: The "free oxygen" in ethanol more than makes up for its low energy. Low energy! Exactly! That's because it's less efficient!!! What it can do when you use more of it is not indicitive of it's efficiency. The fact that it takes more by volume to do the same thing means that it is in fact less efficient. This is backed up by btu and by mileage.

 

A company called Changing World Technologies has been doing somehting simliar with a process it call "Thermal Depolymerization" for a number of years now with actual production facilities

http://www.changingworldtech.com/who/index.asp

 

Here's another thought. If ethanol is 34.7% oxygen by mass, if it's so much more efficient, wouldn't you think that it would need to run leaner? It's supplying some of it's own air. It doesn't run leaner though. Not even close. It needs to be much much richer. It's because it's inefficient!

 

now i just need get some of this bacteria and a gas pump, I wont ever complain about cutting grass again in fact ill love it!

 

The bacteria converts the waste into oil. You would still need to refine it to make gasoline. But, add this bacteria to a large landfill and see what happens.

 

yeah, hope this works out and solves to problems at the same time on a large scale.

 

so on to ethanol-

Have people still not fully read this?

http://www.epa.gov/otaq/presentation...-isaf-no55.pdf

it and others like it have found that yes- under normal conditions found in normal spark ignition motors gasoline/ethanol mixtures produce less mpg because of the LOWER ENERGY DENSITY vs "pure" gasoline.

HOWEVER the study found that using the alcohol/gas mixtures of 10% to 85% and even 100% alcohol in a spark ignited engien with a 19.5/1 native compression ratio you could achieve the same power and mileage OR MORE than "pure" gasoline at normal spark ignited gasoline motors.

its very clear that at the normal compressions pumping in blends is less efficient and as the paper states

and more importantly - to me at least in terms of extending our fuel availability- it that the use of blends in between E10 and E85 have not be pushed or focused on as much as needed.

using something like E30 would offer a huge advantage in rate of return over E85 but it just isn't being pursued - probably because of some political or "green" agenda

 

I don't claim to be an expert on fuels at all, but how is a pulse jet engine at all similar to a piston or rotary engine?

 

it isn't really, I was just trying to show that I've done more research on fuels other than prickhole suggested by saying I just read some website.




RG, if it has oxygen attached to it you would run it richer because the "fuel" part of the AFR ratio would have oxygen ("air") in it.

 

He said he didn't see any power loss on N/A cars either.

 

Actually that would be true. I somehow got that messed up in my head. When I was using the term "richer" in my head, I was thinking in terms of richer air not fuel and vice versa with lean.

Please stop with the name calling. It's not needed.

 

If he has to use more volume of fuel then it's a net loss so even then it would still be irrelevant. This is because it's less efficient. At the end of the day the gas pump dispenses fuel in gallons. You buy ethanol by the gallon. That's the frame of reference that matters. If you need more of it, it's not as efficient.

 

The term efficiency doesn't really fit then. Defined as the ratio of the output to the input of any system. The automakers use fuel and gallons to define engine efficiency.
The engine's efficiency won't change. You just have different mileage values because ethanol is a different fuel.

It has less energy/volume that's undisputed, but it's oxygenation which is worth more power and "cleaner air".

 

The fact that it's oxygenated from a "clean air" standpoint would seem to cancel out since it has to run richer and you have to physically burn more fuel. More fuel equals more pollution.

The engine's efficiency won't change from the standpoint that it can only convert so much % of input energy into useful power output. However if you use a less efficient fuel, even if the engine's efficiency stays the same, the output power will also be less. Less energy in= less energy out. The engine's efficiency doesn't have to change. This stays true. With ethanol you have much less energy going in. Less energy in a fuel equals less efficiency in a fuel. This is why it takes more of it to do the same thing.

 

I know, I know, "but it's oxygenated!". So what? This means absolutely jack squat since a non oxygenated fuel needs to run leaner, which is more air which is more oxygen. It doesn't matter where the O2 comes from. It still gets in the engine somehow.

 

right, but since the oxygen is being injected by a fuel pump and in a much denser form (liquid) the engine doesn't have to draw in the air which is only 20% oxygen. This mean that the engine will have a lot more oxygen in it, from the oxygen it draws in from the air and the oxygen in ethanol. If it didn't make a difference then there would be reason to port an engine, as I've said before the limiting factor of an engine is how much oxygen you can get into the combustion chamber; fuel is always easily added.

 

Then why can't you go as far on it and why can't you make the power with it? Keep in mind that flex fuel vehicles do in fact retune for it and their mileage really really suffers. So does their performance. I've never seen anyone with one of those running on E85 say they had better throttle response. They don't.

At the end of the day, it's a less efficient fuel than gasoline. Period. Arguing about it won't change that. If someone has made more power on a naturally aspirated engine with ethanol than they did with gasoline there can only be one of 2 reasons and I guarantee that mileage would still suffer. Problem one is that the engine had too much compression for gasoline and timing had to be severely pulled out. This is an effect of octane only. The other thing that could cause ethanol to be more powerful assuming the 2 engines are the same and that compression is good for gasoline is that the engine tuner quite frankly sucked. Yes I said it and I know it'll **** someone off.

If you specially build an engine for Ethanol, it's performance can be decent with minimal loss compared to gasoline. It'll always suffer from a mileage standpoint though due to it's lower efficiency. That's lower btu's for you. Less energy in equals less energy potential out hence everyone's lower results.

 

no it wont fred- read the paper

 

Don't you just love it when Admins dissagree?

 

I agree with much of what you say here. But keep in mind ethanol is being worked on with different sources to make it less dependent on corn, and more efficient as a fuel. I think we're still at the beginning of the development cycle, Eventually, some equilibrium will take hold.

I think in the end, the consumer will have several different choices- oil, ethanol based, plug in, hybrid, and eventually, hydrogen.

 

I could care less about mileage from ethanol, it isn't a limited resource. The main waste products of burning any kind of hydrocarbon are CO2 and H2O which are the two main "foods" for plants. Photosynthesis uses the sun to arrange these into a sugar which is converted to alcohol. Ethanol is essentially liquid solar power. The "ineffecieny" of ethanol is related to it's low C:H ratio. You get more exothermic energy from oxidizing carbon than you do from oxidizing hydrogen. This is why you lose power from using things like natural gas (methane CH4) and propane (C3H8) compared to gasoline (basically octane C8H18). The oxygen in an ethanol molecule provides the extra energy in an oxygen starved chamber (our engines) because it requires less oxygen to burn.

The OFR (oxygen : fuel ratio) for ethanol is ~2.1:1 and 3.5:1 for octane (basic stoich calculation by mass). This is conclusive of the 9:1 associated with ethanol and 14.7:1 associated with gasoline. This means 1.63 times more ethanol can be burned than gasoline with the same amount of air. Ethanol has 12,800BTU/lb and gasoline has 18,500BTU/lb. So 12,800*1.63=20864 which is greater than 18,500. The "power" AFRs for ethanol are ~6.5 and gasoline ~12.5 which raises the "BTU multiplier" to about 1.9.

Ethanol cars making less power can be attributed to them probably running leaner AFRs to make the loss of fuel mileage (the only important factor in buying a car it seems...) less.

 

And this is pretty neat alt fuel website I drop in on from time to time- lots of smart people focusing in this.

http://www.matternetwork.com/

 

If someone would have told me a few years ago that people are emotionally disturbed that ethanol would one day be used as a fuel, I wouldn't have believed them. Time has proven otherwise.

I love the one-liners:

"Lets just drill for more oil."

OK, where? I recall a great little oil prospecting company named Spectrum 7 that would be happy to have you invest in them for that purpose. Do a Google on Spectrum 7.

"Ethanol takes more energy then it produces."

Sure, SOLAR energy. But if you believe it takes more oil energy to produce an equal amount of ethanol energy, let me suggest a few perpetual motion machines to invest in.

I don't think anyone disagrees that gasoilne has the best phyical properties for automotive fuel. Its not a question physical properties. Its a question of economics, and rapidly becoming one of national security.

We all know how much we pay at the pump.

But how much are we contributing to supplement the cost of oil? What would happen to our oil supply if the Perisan Gulf were blockaded? Oil around the world including Canada and Venezuala would rise in price, not a little, a lot. You might be surpised at how much the US spends to avoid an interrupt to the flow of oil from the middle east.

If you think oil is high now, wait a few more years. Over the last few years I've been to China and India a few times every year. Every year I am amazed at the number of new cars and trucks, even more amazed at the number of people who are looking forward to buying a car. Even India now has an F1 team funded by a billionaire who owns Kingfisher Airlines. Every Kingfisher flight in india is full and every time I visit Kingfisher has many more airplanes. Thats just India. China's sparkplug population is growing at a rate of 3x per year. And both of those countries are just beginning to step into the motorized era.

Where do you think they're buying their oil?

Earlier I mentioned the Tar Sands. China is financing a 350 mile long pipeline from one of the richest deposits in Canada for exclusive port rights.

Personally I'll use whatever fuel makes the most sense to use. When gasoline reaches $4 a gallon, I'll be looking a little closer at the economics to convert the RX8 over to E85. Not because I prefer the superior performance of ethanol, but strictly the economic reasons.