Important read Ethanol changeover

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Q45tech
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Especially NE and Mid Atlantic and Texas

http://www.eia.doe.gov/pub/oil...6.pdf

http://lfee.mit.edu/public/LFEE%202006- ... ter.htmlIf you only have a small quantity of water, then the addition of 500mls ofdry isopropanol (IPA) to a near-full 30-40 litre tank will absorb the water,and will not significantly affect combustion. Once you have mopped up thewater with IPA, small, regular doses of any anhydrous alcohol will helpkeep the tank dry. This technique will not work if you have very largeamounts of water, and the addition of greater amounts of IPA may result inpoor driveability.

Water in fuel tanks can be minimised by keeping the fuel tank near full, andfilling in the morning from a service station that allows storage tanks tostand for several hours after refilling before using the fuel. Note thatoxygenated gasolines have greater water solubility, and should cope withsmall quantities of water.

[ end extract ]

So your question may be " why IPA, why not methanol or ethanol,which are usually cheaper ?". The answer is dependent on twoaspects, the actual ability to act as a cosolvent, and theeffect of temperature on the phase separation point of gasoline/cosolvent mixtures. The aromatics content of the fuel also hasa profound effect on the amount of water that can be tolerated,with 25% aromatics tolerating about 0.1% water and 40% aromaticstolerating about 0.2% water at 15C.

Adding 15% by volume of anhydrous methanol to a typicalnon-oxygenated gasoline will provide a water tolerance ( theamount of water that can be added before phase separation occurs )to around 0.16% at 15C, but at 0C the tolerance would be close to0%, ie the water/methanol would be a separate phase without theaddition of water. Adding more that 15% of methanol can adverselyaffect driveability on engines without management systems designedfor oxygenated fuels.

Adding about 3% by volume of anhydrous iso propyl alcoholwill provide a water tolerance of about 0.35% at 15C and about0.2% at 0C, thus it's ability as a cosolvent is superior ona volume basis, and far less temperature sensitive thanmethanol.

Ethanol is between the two, with a 15% blend tolerating about1% water at 15C. The best additives are the isomeric propyland butyl alcohols, and above them, the tolerance decreasesas the alcohols become less water miscible.

The above numbers are from memory, and are approximate, butyou get the general idea. The experiment is easy to do if youwant real numbers for your local gasoline. Take 100 mls ofgasoline ( remembering that it's highly flammable ) in astoppered glass measuring cylinder and measure temperature.

Add one drop ( ideally a 1ml syringe, but any narrow tubing ordropper can be used, and use 20 drops of water = 1 ml ), stopper,and shake. If the solution goes hazy, warm slightly in a bucketof warm water and measure the temperature that it clears.If it stays clear, reseal and put it in a fridge or freezer ( ina container that will contain the fuel should the glass break- and remember that all vapour will be flammable and that thecontroller and light use non-flameproof switches ).

When hazy, remove and record temperature that the haze clears,and if it's still clear, add another drop and repeat.

Now repeat adding 5,10,15% anhydrous MeOH, EtOH, or IPA ( rememberingthat many IPA products ( eg as an antistatic ) actually are notanhydrous, and can contain up to 40% water - which somewhatdefeats the purpose :-) ). You can draw a graph of water toleranceversus temperature that shows the different positions and gradientsof the alcohols.


Q45tech
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http://atlanta.bizjournals.com....html

And our situation in Georgia.

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DrewQ45
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Q45tech wrote:http://atlanta.bizjournals.com....html

And our situation in Georgia.
So what's this gonna do to our injectors? (197K and never changed a one)

96Qowner
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I don't think it's the ethanol that causes the injector failures. I looked into it once - Googled for awhile - and didn't turn up much.

My understanding is injector problems are caused by poor quality detergent additives, and regional contaminants in the original bulk fuel. You can defeat both with periodic use of BG44K.

Ethanol just gives you less power, water in your fuel, and a slight risk of dissolution of hoses and other sensitive seals.

Q45tech
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The water in fuel is a major cause of pump and injector failure from rust and corrosion.

Gasoline can only hold 0.05%, with MTBE more 1%, and 10% ethanol 4 to 10 times as much water depending on temperature.

The fuel system sock/and under hood filter was designed to handle just a few ounces of water not a pint [16 ounces].

2.25 gallons of ethanol in 22.5 gallons can contain up 10% water [28 OUNCES]. From the tank rail car it is supposed to be <5% water.

THE PRIMARY ADDITIONAL SOURCES OF WATER are already in the stations gasoline tanks.....every time it rains the humidity comes down the vent pipe and condenses in the tank.

Do you honestly think they dig up every tank and replace or send a tiny robot down to scrub them clean.

The problem will be at it's worst the first week or two unless it rains later.

95% isoheet in every tankful for a few weeks might tide you thru

Q45tech
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As to Georgia specifically our premium is a boosted conventional that last year averaged 4.85% MTBE with 0.5% Benezene fractions less than half the amount of MTBE used in reformulated versions.

So we will double the level of oxygenates via Ethanol.

96Qowner
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Aha, it's rust particles that may cause injector failures.

http://www.findarticles.com/p/...71885

Back in the 80s and early 90s, there were some issues with ethanol dissolving the insulation in injector windings.
Modified by 96Qowner at 8:32 AM 4/13/2006

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Q45denver
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Ethanol breaks down the varnish on the electrical wiring. My understanding is that is why the coils go out on the 90-93 injectors.

Q45tech
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Not really the ethanol but the reaction products of ethanol, water, and gasoline and the extreme hot soak after turn off.

Removing the insulative varnish makes the resistance drop vs most injectors go higher in resistance.

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Ozzie
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I think I am glad there is no ethanol in our fuel here....

Doesn't sound good

greg_atlanta
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Are most new cars safe using an ethanol blend? (not talking about the E85 vehicles)

I do plan on buying a new car whenever the '92 Q bites the dust, anywhere from 3.5 Altima to G35 or 325i. I would hope most new cars can handle the extra water.

What about recent model used cars? Are most safe with ethanol?

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kimrober
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Wow... I was just watching news on TV and they say now the State of Hawaii requires gas stations to add 10% of ethanols to their fuel mixture for the environment issues. They say by adding ethanol, the amount of CO gas released are reduced by 30% or something for the price of losing your car's gas mileage by 2% or so.


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