Some Chemical Thoughts on Ethanol Problems in Gas

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2,397
Location
Pennsylvania
I have been wondering about the "corrosive" effects of ethanol for a time. It is certainly easy to understand that ethanol may have adverse effects on some polymeric or plastic articles, either through direct solvation or through the extraction over time of plasticizers and/or processing oils and aids. Such behavior can cause shrinkage of seals, etc. But what really got me thinking about ethanol was throwing out a wine bottle the other day. It made me think of wine turning to vinegar through the oxidation of ethanol to acetic acid. There is no doubt that this is what can occur in gasoline with ethanol. And just think what adding a few drops of glacial acetic acid to your lawnmower gas tank would do over time...cause rust to form, eat through metal parts, form metal acetate salts that can clog up the orifices in small carburators. The list is probably endless. This is one reason that adding an antioxidant helps with ethanol containing gasoline. Stabil, usually with something similar to BHT, stops the oxidation until it is used up as a sacrificial material. But what if some acetic acid does form? If you look at the additives in gas to keep valves clean, you find aminated materials (Shell "Nitrogen", for example). Acetic acid can form salts with amines and I am wondering if the use of these amine materials in gasoline are actually exacerbating the problems of ethanol oxidation? Such salts would be gummy, sticky and probably relatively insoluble in gasoline. What would dissolve them? Something quite polar like acetone, MEK, ethyl acetate, etc. This may be why something like Kreen works in gasoline. Any thoughts would be welcome.
 
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19,479
Location
Chicago Area
"there is no doubt"? Really? Ethanol in gas turning to vinegar? Methanol is hard on parts, ethanol not nearly as much. But it is a problem for fuel pumps due to lack of lubricity . High concentrations [like E85] are rough on engine oil, too.
 
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15,500
Location
N.H, U.S.A.
I think the bottom 1/8 tank is water/ethanol in my new truck - when I get this low truck almost stops ruuning. I got to figure out how to drain this beast. I've read it only take a few TBS of water/Gal to cause phase separation. I think I liked mTBE better.
 
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cmf

Messages
415
Location
Florida
If you're storing fuel, these byproducts will form and be a factor. That is why products like Sta-bil are recommended for the storage of fuel. In cars that are driven every day, the byproducts are consumed continually to where they cannot form to such a great degree to be detrimental. Gasoline without ethanol would be better, but ethanol is not the end of the world. The greater issue than small amounts of compounds forming is the fact that ethanol is hygroscopic which can be an issue in cars with gas tanks that do not properly seal. Leaving gasoline in those cars for what would normally be acceptable periods can become an issue with ethanol. The glacial acetic acid is a really bad example. Ethanol first has to be oxidized to acetaldehyde then further oxidized to acetic acid which is a weak acid that is not going to do much in small quantities. People on this forum put MMO into everything and that has chlorinated hydrocarbons. Hydrochloric acid beats acetic acid's butt any day of the week. In short I doubt your ethanol containing gasoline is going to acidify enough to damage your car. I would prefer gasoline without ethanol, but there is a gas station nearby that offers it and I go to a Shell station across the street instead. Why? Because the Shell station sees much more traffic and is newer. I consider those two factors to be more important than 10% ethanol in my gasoline.
 
Messages
8,859
Location
Texas
Just as a data point, I've been driving my everything from my '66 Dodge Polara and '69 R/T to my 08 Ram 1500 on E10 for several years now. ZERO problems in any of them. Granted, I did replace all the old fuel line on the '66 with fuel injection grade hose when I did a major overhaul and engine build on the car back in 2004. But it still has a Carter carburetor and original 45-year-old fuel tank. I honestly believe that there are NO issues, chemically anyway, with ethanol and fuel systems in a 10-15% blend. E-85 is probably a different story, but I couldn't run the old cars on that without re-jetting the carbs and losing the ability to run on E10 altogether. Don't get me wrong, I don't like Ethanol blends and think its a huge crock because its a net energy waste (takes more energy and produces more CO2 to make it than you save by using it). But its not directly harmful to the cars. The biggest problem I personally have with today's fuel is the high vapor-pressure winter blend fuel. Both the '66 and my 2001 Jeep are very prone to vapor locking on a hot day in February when the stations are selling winter-blend fuel. I've pretty much cured the '66 by adding a pusher fuel pump, but the Jeep's problem is heat soak of the #3 fuel injector (there are a few TSBs on it) and its not an easy fix. I pretty much just live with it for a few months of the year- it runs rough and throws a CEL if you start it up within 10-15 minutes of a hot shut-down on a hot day. The funny thing is that BOTH cars are perfectly fine in 105F summer weather like today, when there's summer-blend fuel in the tank. But give us an 80-degree day in March and they both have problems.
 
Messages
22
Location
KY
It's going to bond with moisture and fall below the rest of the mixture long before it will oxidize, and that will be harder being it is covered by the remaining gas.
 
Messages
22
Location
KY
Originally Posted By: ARCOgraphite
I think the bottom 1/8 tank is water/ethanol in my new truck - when I get this low truck almost stops ruuning. I got to figure out how to drain this beast. I've read it only take a few TBS of water/Gal to cause phase separation. I think I liked mTBE better.
It doesn't take much. Humidity in the air will cause ethanol to fall out of suspension after some time.
 
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Messages
14,799
Location
Illinois
We have had E10 here in Illinois for many years now and I know of no one that has had a problem with it. It's graet for winter use as well.
 
Messages
895
Location
Midwest
Originally Posted By: tig1
We have had E10 here in Illinois for many years now and I know of no one that has had a problem with it. It's graet for winter use as well.
It doesn't do well in small engines. Look at states like Minnesota where E10 is mandatory. They still have "off-road use" pumps at some stations - usually the ones around the lakes. Outboards, particularly the older ones of which there are tons still in use in MN, just do not run correctly on E10 (and may cause damage to their parts). I worked for a county conservation board. We were required to fuel the vehicles with E10 by the state since we were a gov't entity. At our fuel depot we had 3 tanks. E10, diesel and 87 octane 100% gas. Procedure was to run E10 only in the 3 pickups. The tractors (including an old Farmall M from the 60's), Bobcat, front-end loader, mid 70s dump-truck, riding mowers, boats, Mules, and all handheld power equipment was fueled with 100% gas.
 
Messages
4,798
Location
Lakeville, MN
Yes, E10 has been mandatory except for premium at select retailers in Minnesota for at least a decade now. At this point, we have no issues running E10 in virtually anything we own, including those old outboards at the cabin (76 Johnsons in 6 hp and 55 hp and an 85 20 hp Johnson) have been running fine for years on the stuff, although all of them have had fuel lines and carbs rebuilt since E10 became as common as it is (would have needed to be done on all of them regardless). Same story on the other OPE at this point too. Our "key" is to keep fuel stockpiles relatively low to keep the fuel fresh along with use of Stabil in all OPE fuel, regardless of the plan on when to use it. We've had no issues.
 
Messages
558
Location
Orange Park, FL
We have had E10 here in the Chicago area since at least the mid 90s....haven't had any issues related to it. With that said, any modern day engine and fuel system is engineered to run on a 10% ethanol blend. The engines and fuel systems having issues are the older "pre E10" designs that were not engineered to handle alcohol. Personally, I'd like to see them get rid of alcohol blended gas because the fuel economy isn't as good as 100% gas.
 
Messages
558
Location
Orange Park, FL
Originally Posted By: ARCOgraphite
I think the bottom 1/8 tank is water/ethanol in my new truck - when I get this low truck almost stops ruuning. I got to figure out how to drain this beast. I've read it only take a few TBS of water/Gal to cause phase separation. I think I liked mTBE better.
Just do what most people do, dump a couple of bottles of ISO HEET (red bottle) in the tank. lol
 
Messages
14,799
Location
Illinois
Originally Posted By: buickman50401
Originally Posted By: tig1
We have had E10 here in Illinois for many years now and I know of no one that has had a problem with it. It's graet for winter use as well.
It doesn't do well in small engines. Look at states like Minnesota where E10 is mandatory. They still have "off-road use" pumps at some stations - usually the ones around the lakes. Outboards, particularly the older ones of which there are tons still in use in MN, just do not run correctly on E10 (and may cause damage to their parts). I worked for a county conservation board. We were required to fuel the vehicles with E10 by the state since we were a gov't entity. At our fuel depot we had 3 tanks. E10, diesel and 87 octane 100% gas. Procedure was to run E10 only in the 3 pickups. The tractors (including an old Farmall M from the 60's), Bobcat, front-end loader, mid 70s dump-truck, riding mowers, boats, Mules, and all handheld power equipment was fueled with 100% gas.
As for small engines, my 22 year old Honda mower has never had a fuel related problem, and my 11 year old Echo weed wacker has had no problems either. We have had E10 here for many years now.
 
Messages
5,500
Location
Florida
Funny, i keep having fuel related issues with 2 of my lawnmower for the past several years... Carburetors completely going bad. I don't know who or what to blame for this though.
 
Messages
1,478
Location
Iowa
Originally Posted By: Boomer
It made me think of wine turning to vinegar through the oxidation of ethanol to acetic acid. There is no doubt that this is what can occur in gasoline with ethanol.
Ethanol oxidizes into acetic acid through bacterial processes (http://en.wikipedia.org/wiki/Acetic_acid_bacteria). I'm guessing that this bacteria couldn't survive in a solution that's 90% gasoline?
 
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