E85Forum.com

secure · Joined: 22 Apr 2010 Posts: 2

Hello!

I'm new to forum and alcohol as a fuel.
I am wondering about the differences between Methanol and Ethanol as a fuel. Which is better for a race car and why?

What is the problem with E85 fuel on cold wheathers? Combustion problems? I'm tuning my own car and running a Liferacing standalone ecu and thinking of running E100 all the time for daily drive. What would be the problem for me?

I dont know the details of cold start problem so I can't think about a tuning strategy for that but I have very capable of ECU can run 8 different maps switch function including cold start enrichments bla bla bla

secure · Joined: 22 Apr 2010 Posts: 2

I forgot to ask the main question!

What is the mix of the alchol you guys are using? Is it pure alcohol (%100 alcohol) or %96 alchol and %4 water?

Alcohol · Joined: 17 Apr 2007 Posts: 634 Location: Central Wisconsin

If you are in the USA you will not easily get your hands on hydrous H100 (ethanol 4-6% water) unless you brew your own. Also you will have a very very hard time getting E100 annhydrous (dry) because of BATF rules. What you can get is drums of E98 (dry annhydrous ethanol with 2% gas for poison to prevent drinking of it). What most are talking about running here is E85 (ethanol 85%/15% gas) because it is available in over 2,000 stations nationwide. The reason for the 15% gas is to vastly improve starting-- this allowed automakers to make flex-fuel vehicles that do not need to start on gas and then switch over to alcohol on warmup. The 15%-30% gas raises the vapor pressure of the E85 to near gasoline making the starting a non-issue for consumers. The USA has 3 blends of E85 at retail pumps; 1) E85 summer, 2)E78 spring/fall, and 3) E70 winter to make starting the same as if running gasoline.

Methanol also is very hard to start on in -- we once had a few M85 stations and govt cars around. These fell out of favor to E85 since ethanol has far better mpg and is far less corrosive to metal parts.

Brazil is different- it uses H100 (hydrous (wet) ethanol and does not mix it with gas. Some older vehicles have a small gas tank that allows starting on gas. Their climate is warmer which allows this approach.

mus302 · Joined: 12 Jan 2008 Posts: 3 Location: Knoxville, TN

I think another reason why M85 has fallen out of favor is the fact that methanol is poisonous not only when ingested but also through breathing the vapors or the liquid coming into contact with the skin. You really have to be careful around the stuff.

Eric68 · Joined: 01 Nov 2007 Posts: 331

Drag Chevette · Joined: 18 Sep 2007 Posts: 458

Ethanol vs Methanol

Methanol and Ethanol both have advantages and disadvantages over fossil fuel gasoline. For instance, both alcohols can run at a much higher compression ratio without octane-boosting additives

Alcohols burn more completely because their molecules contain oxygen;
Oxygenated chemical compounds contain oxygen as a part of their chemical structure. The term usually refers to oxygenated fuels. Oxygenates are usually employed as gasoline additives to reduce carbon monoxide that is created during the burning of the fuel….. Carbon Monoxide is BAD!

The oxygenate MTBE has been found to have contaminated groundwater, mostly through leaks in underground gasoline storage tanks. In 2004, California and New York banned MTBE, generally replacing it with ethanol.(Ethanol is Biodegradible…..wont harm the environment!)

Alcohol fuels such as methanol and ethanol, are partially oxidized fuels and need to be run at much richer mixtures than gasoline. As a consequence, the total volume of fuel burned per cycle counterbalances the lower energy per unit volume, and the net energy released per cycle is higher.

carbon monoxide emissions are 100% lower than fossil-fueled engines because the only products of an alcohol combustion reaction are carbon dioxide (plants breath this), water (plants need this) , and heat .

Methanol is the lightest and simplest alcohol, produced from the natural gas component methane. Its application is limited due to its toxicity…..IT WILL KILL YOU!
PURE Ethanol, also known as grain alcohol or ethyl alcohol, is most commonly used in alcoholic beverages. However, it may also be used as a fuel….YOU CAN DRINK IT!..but dont because it is denatured so you CANT!

Larry can correct this if im wrong, but i believe that:
Methanol’s octane rating is 129 (RON), 103 (MON), which equates to 113 (AKI)
Ethanol's octane rating is 129 (RON), 102 (MON), which equates to 116 (AKI).
Gasoline is approximately 91 (RON), 81 (MON), equal to 86 (AKI)
AKI is 'Anti-Knock Index'
contrary to popular belief.....It should be noted that octane rating does not relate to the energy content of the fuel or heating value, nor the speed at which the flame initiated by the spark plug propagates across the cylinder. It is only a measure of the fuel's resistance to autoignition.

Ethanol is harder to ignite than Methanol.
Ethanol is less likely to have detonation than Methanol.

Ethanol has 27% less energy per Gallon than Gas.
Methanol has 55% less energy per Gallon than Gas.

This is why more volume is required for each of the Alcohol fuels and why Methanol take almost twice as much fuel as Ethanol over gasoline.

If gasoline is run at its preferred maximum power air/fuel mixture of 12.5:1 air/fuel ratio, it will release approximately 20 MJ (about 19,000 BTU) of energy, where ethanol run at its preferred maximum power mixture of 6.5:1 air/fuel ratio will liberate approximately 25.7 MJ (24,400 BTU), and methanol at a 4.5:1 air/fuel ratio liberates about 29.1 MJ (27,650 BTU).
Methanol makes the most power (29.1 MJ), but also takes more fuel than Ethanol to make that power…..
Apples to Apples….. Ethanol will out perform Methanol.
Methanol gets its power from the volume consumed.
Combustion:
Methanol combustion is: 2CH3OH + 3O2 → 2CO2 + 4H2O + heat
Ethanol combustion is: C2H5OH + 3O2 → 2CO2 + 3H2O + heat
CO2 = carbon dioxide (plants breath this)
H2O = water (plants need this) ,
heat = heat.

As you can see above, Methanol produces more water during combustion than ethanol. Methanol = 4H2O to Ethanol = 3H2O….
Hydrogen (H) may reduce knock by contributing its high thermal conductivity
Methanol has 4 hydrogens, Ethanol has 6 hydrogens,
= Ethanol absorbs more heat and therefor is more energy efficient, effeciency in the right conditions is power without the knock.
Given the higher octane rating of Ethanol, Modified engines are capable of generating equivalent or higher horsepower and torque burning Ethanol than conventional gasoline despite the lower energy density of Ethanol.

Alcohols higher octane allows an increase of an engine's compression ratio for increased thermal efficiency. In one study, complex engine controls and increased exhaust gas recirculation allowed a compression ratio of 19.5 with Ethanol to E50…..

With Ethanol thermal efficiency, up to approximately that for a diesel, was achieved.
This would result in the MPG (miles per gallon) of a dedicated ethanol vehicle to be about the same as one burning gasoline…..your not getting that with Methanol because of the volume needed to produce the power!

Hope this helps set some things clear……

Phil, please correct any mistakes that you may find in this.

murphinator · Joined: 08 Jan 2010 Posts: 93

^thats a heck of a post !
_________________
PB's 1/4 mi 12.209, 117.75 trap ,1/8 mi 7.76 ,93.99 trap , 1.949 short time 4.53 0-60

I tune with HP Tuners software

rmay635703 · Posted: Tue Jun 15, 2010 4:54 pm Post subject:

Alcohol · Joined: 17 Apr 2007 Posts: 634 Location: Central Wisconsin

You are not the only one who feels that way (though i disagree about there being problems with the mix- at least with dry booze). There are heated fuel injectors being tested by Delphi that would be better and safer than glow plugs but the problem is just as you implied- once the E85 network is up- how do we switch to HE100 while still serving the E85 FFV's?

Some Danes have proved that in a milder climate the HE100 will blend ok with gasoline as long as the % alcohol is over 5%. There is a test of hydrous ethanol/gas mixes (and straight HE100?) approved for retail down in Louisiana but I have not heard much about it- retail may not be built yet.