It is all about content

Ken Garlock

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For some time I have been curious about the use of Ethanol in place of gasoline. I did some googling today, and found a table of energy content for various fuels. You can find the comparisons at the Oak Ridge National Laboratory website.

At the ornl I found what I had been looking for, energy content of various fuels.
A quick summary:

Gasoline 115,000 BTU/gal.
Ethanol 75,700 BTU/gal.

Petro Diesel 130,500 BTU/gal.
The numbers for Bio Diesel were not given in imperial units. However, a comparison in Joules/Liter can be made.
Petro Diesel 36.4 MJ/liter.
Bio Diesel 35.7 MJ/liter.

Observations:
Ethanol contains only .658 the energy of gasoline.

Gasoline contains 1.519 times as much energy as Ethanol.

Bio and Petro diesel are roughly equal in energy content.

What does this mean? For Ethanol to be equal to gasoline,
1) it should cost 65% of gasoline.
2) you will only get 65% of the mileage on a tank Ethanol compared to gasoline.
3) Diesel beats both, based upon energy content.

You might say, but Diesel is dirty and smelly. I say it doesn't have to be. My 2007, 3.2 liter, 208 hp, V6 diesel powered car a) does not smell, b) does not smoke, c) is locally approved in all but the tree-hugger states. And, I get 29.5 MPG in mixed city highway driving. The 2008, 215 hp, model is approved in ALL states.

I say, process the used cooking oil, and forget about Ethanol. Ethanol belongs in your glass, not in your car.
 
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I agree as well... and I even own an E-85 truck. You can imagine my dismay when I found out that the price of ethanol around here is about $0.35/gal higher and would get me ~75% the mileage. How "smart" is that? Needless to say, I've not yet filled it with ethanol... but it's still nice to know I can in a pinch.;)
 
The rating you gave for ethanol, is that for pure ethanol or E-85? Gasoline with no additives at all (very difficult for the US consumer to come by) has almost no oxygen - adding oxygen, whether by MtBE (methyl-tert-butyl ether) or ethanol will increase combustion efficiency, meaning less unburnt fuel sent away from the engine.

The other interesting thing was that gasoline gives 35 MJ/L and natural gas (this is the same as propane, right?) gives 34.6 MJ/m^3. A L is 1000 mL, a mL is a cubic centimeter (cc) and there are 1,000,000 cc in a m^3, so natural gas gives 1,000 times the efficiency of gasoline.
 
All true and now that we are putting CORN in our cars and not into our cows the cost of everything is going UP.

Isn't this the perfect example of a government controlled commodity. It is less efficient, costs more and is causing every thing else to cost more.

Hey we elected these turkeys :huh::huh::huh:
 
The rating you gave for ethanol, is that for pure ethanol or E-85? Gasoline with no additives at all (very difficult for the US consumer to come by) has almost no oxygen - adding oxygen, whether by MtBE (methyl-tert-butyl ether) or ethanol will increase combustion efficiency, meaning less unburnt fuel sent away from the engine.

The other interesting thing was that gasoline gives 35 MJ/L and natural gas (this is the same as propane, right?) gives 34.6 MJ/m^3. A L is 1000 mL, a mL is a cubic centimeter (cc) and there are 1,000,000 cc in a m^3, so natural gas gives 1,000 times the efficiency of gasoline.
I think you did that backwards. Let's compare a cubic meter of each fuel. There would be 1,000 liters of gasoline in a cubic meter, or 35,000MJ. The same cubic meter of natural gas (or propane) would only have 34.6MJ. So a cubic meter of gasoline would have 1,000 times the energy content of a cubic meter of natural gas.

But that comparison is fallacious. You can't compare a fuel in liquid form to another fuel in vapor form and expect to get a valid comparison. You'd have to liquify the natural gas and compare it to liquid gasoline - or vaporize the gasoline and compare it to the natural gas in vapor form.

Mike
 
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The other interesting thing was that gasoline gives 35 MJ/L and natural gas (this is the same as propane, right?) QUOTE]

WRONG. I'm no chemist Mark, but I do have first hand knowledge of some differences. One major difference is that if a valve on a "Natural Gas" pipe is opened to the air, the Natural Gas will rise and dissapate by mixing with the air, whereas Propane when opened to the air will settle to the lowest spot and it takes a Looooooooong time for it to dissapate , (which makes a Propane leak more dangerous to deal with). Also there are differences between Liquid Natural Gas and Propane which is stored in a liquid form. Some public vehicles like School and Local Busses are now run on LNG, (liquid Natural Gas) but it is only cost effective on a local basis because of the specialized storage/handling facilities and their short range of operation.

My Dad worked for a Natural Gas Company for 31 years , (and I did too for 1 yr while going to college at night), and in the early '50 s, the company switched to all Ford 6 cyl pickups, (and a few years later switched their Gang Trucks also), and ran them all on Butane/Propane as the primary fuel, (although they could still switch an electric valve and run on Gasoline when needed, which they did after a given number of Butane fillups, to keep the gasoline Fresh). The Butane/propane burned cleaner and the engines lasted longer, but the power was less and the mileage was less than when they were run on Gasoline.

One thing I find ridiculous, is the prices they are charging these days for Diesel. A large part of the price is most likely the Greed of the Fed and State Govts and their taxes of that fuel, (since it is mostly used by Truckers) because it is a cheaper fuel to produce than Gasoline, (comes off the "cracker" in the refinery process before Kerosene, Jet fuel (which is highly filtered Kerosene with additives), and long before the many grades of automotive and Aviation Gasolines). I wonder if the Railroads are being charged the same taxes, (except for the road use taxes)?
 
E-85 is a killer for outboards and although my new truck will run on it, I shudder to think of pumping it into my tank. My S-I-L's car runs on pure Ethanol but then it only gets 2 gals per quarter mile.

I get "Re-formulated gas" here in the tri-state area... Sucks is best offer I know. my truck gets at best 14.5 mpg with it but I can go out of town and buy gas and get 15.3 mpg. where is the EPA when I have to pay my gas bill. How can you save the planet when you have to burn more fuel to do it?
 
There was a good article in National Geographic a couple of issues back about 'bio-fuels'. Making ethanol from corn has little net gain, sugar cane is much better. Both have environmental issues and are not without 'side effects'. Lots of corn to fuel legislation is supported by the big corporations that will profit from it. The fact that it doesn't actually produce a net energy gain seems of little importance. It won't solve our energy problems but will make some very rich.
 
Ken, what car do you drive that gets 29mpg on diesel and doesn't smell bad?

Ken

I'm not Ken, but I had a Rabbit Diesel 4-speed that got 45-50 MPG in town, didn't put out black exhaust, and didn't rattle like most diesels do. The Mazda diesel we had in our Ford Ranger got 40-45 mpg, no black exhaust, and very little rattle. IMHO, the diesel that was in that Rabbit is probably the best diesel engine around--and it had great acceleration and I could maintain 70-75 MPH on the interstate with no effort whatsoever. I sometimes wish I had it back.

Nancy (39 days)
 
VW rabbbits can be awesome, if you don't mind a little puff of black smoke you can really make them run with little or no damage to fuel economy.

I can live with the rattle of a diesel. At least I know its working then. :rofl: They do quite up quite a bit when switched to bio diesel. The wifes cousin is big into it here on the farm. You can tell just from the sound of the tractors and his pickup when its running BD or straight diesel. Besides the BD smells like French fries.
HHHHMMMMM French Fries :D
 
Ken, what car do you drive that gets 29mpg on diesel and doesn't smell bad?

Ken

My new car is a 2007 Mercedes Benz E-class with a 3.2 liter V-6 diesel. It is rated at 208 HP, with 388 ft-lbs of torque. It is a full size car, none of tiny box on wheels. I bought at the end of August as a dealer demo. I expect to keep it for a long time. My last M/B was a 1995 C-280 that I had for 13 years. The diesel engine uses what M/B calls a CDI system, Common rail Direct Injection. The injectors shoot the fuel into the cylinder at a mere 25,000 pounds pressure. The compression ratio is 17.7:1. No waiting to start up, just jump in and turn the key.

Ken, if you go to the Mercedes Benz website and select Germany as "your country", you can browse what they sell in Europe. You will see that most of the models are diesel. Of course most of us can't read the write-ups, but you can get a feel for what they offer.

BTW, that 29MPG was for a 500 mile, 17 gallon used, tank of fuel. The actual tank is 21+ gallons.
 
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FWIW, propane and Nat Gas are not the same. The reason I know this is that I have an emergency electric generator that will run on NG or Prop. As a NG generator, it is rated as 13.5KW. On Propane, it's rated at 15KW! I still run it on NG for the convenience since I have NG piped to the property but it clearly shows that there is a difference between the two.
 
Just for the record, diesel is actually a by product of gasoline production so it costs the refiners little to nothing to refine it to it's final state. That's why it was so cheap for about 100 years. Then in the 1980's the auto manufacturers starting building diesel powered passenger vehicles and the oil companies got pissed. The result was an almost immediate price hike. They now make around three times the profit from diesel that they do gasoline. Boils down to one thing, plain and simple... greed. And it's running amok in America today. Too bad.
 
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