www.northerndtool.com/...efficiency

Just a "rant" about Ethanol fuels ...

Per litre it has 21.2 MJ of energy. Since I realize that most here are American I'll use both systems, you end up with 80.25 MJ/US Gal.

• Gasoline with a Octane of 91? 34.8MJ/L or 131.73MJ/Gal.
• So you end up with 90/10 (90% gasoline and 10% Ethanol) having 33.7MJ/L or 127.56MJ/Gal.
• That newish E85 they are pushing? 25.2MJ/L or 95.39MJ/Gal.

Car engines have a maximum efficiency of 37%, cars cannot EVER pass this limit. Most new "fuel" efficient engines are only at 20%.

So on say a Harley with it's 48mi/Gal. One Gallon of Regular fuel Octane 91, and assuming a 20% efficiency, means to drive 48 miles you need 26.35MJ's of energy, this is more or less a "absolute", in that you can't suddenly make the bike use only 1MJ of energy to do the same distance, regardless of what fuel you use. Since Harley says "under ideal laboratory conditions", we all know real world fuel economy will be worse then listed, but that 26.35MJ's of energy can be considered a minimum energy we'd need to move the bike.

If you use 90/10 you'd need

131.73MJ/Gal / 127.56MJ/Gal = 1.03 Gallons of fuel.

E85?

131.73MJ/Gal / 95.39MJ/Gal = 1.38 Gallons of Fuel.

Now as for "pollution" to get us to where we are going.

When you burn Gasoline you end up with this equation:

2 C8H18 + 25 O2 → 16 CO2 + 18 H2O

Ethanol?

C2H5OH + 3 O2 → 2 CO2 + 3 H2O

The molar mass of Gasoline is ~0.75g/cm^3 (100oz/gal) while for Ethanol it is ~0.79g/cm^3 (105.4oz/gal)

So in one Gallon of Gasoline you have 2835g of gasoline.

In one Gallon of 90/10 you have 2552g of gasoline and 299g of ethanol.

In one Gallon of E85 you have up to 425g of gasoline and 2456g of ethanol.

The molar mass of gasoline is ~114g/mol, while Ethanol is ~46g/mol.

• So in regular gasoline you have 24.9 mol of gasoline.
• 90/10 you have 22.4 mol of gasoline and 6.5 mol of ethanol.
• In E85 you have 3.7 mol of gasoline and 53.4 mol of ethanol.

As per the above chemical equations, you end up with eight times the CO2 in moles then you have in gasoline, and two times that of Ethanol.

• So regular Gasoline has a easy 199.2 mol of CO2.
• The 90/10 stuff has 192.2 mol of CO2.
• And E85 has 136.4 mol of CO2.

So that looks like Ethanol has a "good" trade off in CO2 emissions. Which is what everyone talks about. And perhaps they are right. But remember my fuel efficiency conversions I mentioned above?

• Regular Gasoline simply produces 199.2 mol of CO2 to get us 48mi down the road.
• The 90/10 stuff now requires 198 mol of CO2 to get us to 48mi down the road.
• And finally the E85 stuff now requires 188 mol of CO2 to get us the same 48mi down the road as the other two.

So while Ethanol costs us more at the pump then crude based gasoline, even with the lower production of CO2, we still end up within 6% of the same amount of CO2 being released in the air. Which is more then eaten up due to efficiency losses caused by dirty air filters, oil changes, tune ups etc.

Dimitri

Dimitri, why bother about CO²? I've been told by a bio-engineer that CO² is a first-order reaction. When the amount CO² increases in the air, this is fertilizer for all the green stuff on earth which immediatly increases exponential it's capability to consume this CO².
Think about all these fires during the many thousands of years the earth already exists and when there is 1 thing kept realy stable over all these years, then this sure will be the % CO² in the air.

So IMHO all these words about CO² are only meant to test the feelings of the common people about a new tax they want to introduce...

Aloysius,

People in General are stupid and believe that CO2 is a evil Greenhouse gas that must be stopped, and they feel good driving around fuelling up on Ethanol for that exact reason. But the difference in CO2 emissions isn't much once you factor in the difference in energy of the fuel.

Dimitri

oh oh... the green house gas debate?????
very interesting D thankyou for sharing that as its something I hadnt heard about before.

Don't get me started on the stupid politics involving ethanol & bio-diesel fuel . Depending on who you ask, Dept of Energy says 40% loss on fuel mpg verses regular gasoline or EPA which says 30% loss on mpg verses regular gas, Bio-Diesel fuel lacks lubricants for Diesels when bought from the local pump. Our company has 32 OTR & 14 30' straight bed trucks all diesel and every single truck has had the fuel pump, injector pump, transfer pump replaced at least once already.

On the heavy duty Detroit Diesels, Cummins, Cat , Navistar, engines, on 25 trucks injector pumps were replaced before 70,000 miles.......On a Diesel!!!

When opening up the pumps, it was nothing but scored lines on the aluminum housing and 8 of them were so bad (egg shaped) we had to buy a new or rebuilt pump which I tore apart and put steel sleeves in before the truck went into service.

Now we have made Bio-Diesel fuel ourselves and yes you have to apply for it by paying state and federal taxes on the amount you can make per year. We made 2000 gallons last year of homemade Bio-Diesel, Bio-Fuel for one straight bed 30' truck with an International engine in it and the engine never once had any fuel pump failures or for that matter any failure with the engine.

I'll get off my rant stool now. Read this www.businessweek.com/l...058678.htm

While I agree with Dimitri's deduction, I think CO2 is the least of the worry in using ethanol.

IMHO, renewable fuel source is higher in the list.. Much higher!

Geland,

Even if the American's converted every acre of land that can be possibly used to farm corn, instead of all other food stuffs, they still could not meet their fuel requirements.

Similar in most of the world really. It is just not practical to go for biofuel.

Dimitri

Omnivision my work place has bought new DAF trucks and they have diesel and aquablue which is added to the fuel. I believe it is a urea product!!!!

en.wikipedia.org/wiki/...aust_fluid

Dimitri

yip that explains it thankyou.

I look at it this way Dimitri:
take the compression from 9:1 for a gasoline engine to 14 - 15:1 for ethanol and you get the same mileage from alcohol as you were getting from the gasoline at 9:1 BUT you get nearly 30% more power because the alcohol burns slower, is more volume in liquid form, expanding more as it evaporates and burns and the water that is in it is super heated into steam which provides more push on the piston through more of the crank rotation.
While I agree that corn alcohol is not the answer I do know that with 5 acres of land filled with juruselam artichokes you can make over 10000 gallons of alcohol a year. Mix that with 20% water and you have enough fuel for two to three cars for the year.
This is in engines built to take advantage of the anti-knock characteristics of ethanol and tuned to make mileage and power.

Paul,

You cannot get the same mileage out of Ethanol fuel that you can out of gasoline, its a simple issue of engine efficiency (which is fixed for internal combustion engines regardless of the fuel source), and the energy required to move the car.

You need to burn more ethanol by volume to travel the same distance as you would Gasoline.

The United States has a total of just under 2.3 billion acres of farm land. Your claiming 2000 gallons per acre, that is 4.6 trillion gallons of ethanol.

ucce.ucdavis.edu/files...-61784.pdf

According to this the yield is much less. A mere 441 gallons per acre.

In 2011 the United States consumed 134 billion gallons of gasoline, which would take 1.64 times the volume to produce the same amount of energy. Which would mean 220 billion gallons of gasoline would be needed.

Production according to that report would peak at 1014 billion gallons. And that is even assuming that farm land that can barely support such things as cattle grazing and wheat production which is no good for anything else could be used. That is a big if.

And this is not including diesel (60 billion gallons a year), jet fuel (20 billion gallons a year), and other uses that add up quite a bit for crude.

Dimitri

So what is your take on biodiesel in turbo-charged engines?

We use additives made by Power Service and have not had any major problems as all our trucks are equipped with turbos. It was when bio-diesel first came out in our area commercially there was no additives here at that time.

Theres an old urban legend (conspiracy theory) out there that some one actually a good many someones have invented fusion? engines that run on water ie the molecular structure of H2O is broken and the energy released is where the power comes from. The fuel is easily sourced but here's the ringer - when patents are applied for the Fossil Fuel Nations buy the whole thing lock stock and barrel and mothball it because it would decimate their economy.
Anyone else heard about this?