E85 price is sure coming down

[hoosierdoc]

Of course ethanol has a pH

Everything organic has a pH and you could probably argue that inorganic compounds have a pH depending on the definition of an acid (bronsted lowry, lewis etc..)

If Wikipedia is correct in stating that the pKa is 15.9 than that value is related to pH by the negative logarithm of pKa.

So.... pH = (-log)pKa---------- if you use the inverse log function on your calculator which is 10^x power times the pKa 15.9 you should derive a number around 7.9 which represents the pH. So Ethanol is slightly basic which is consistent with the idea that that OH (hydroxide ion) the characteristic feature of alcohols is present in solution.

too much math and science for me

pH of Ethanol

 

[Tula47]

Hmmm... degree in chemistry... I don't mean to insult you, but it probably will... in order to have a ph does something not have to be in aqueous solution giving up H+ or OH- ions?

Gasoline doesn't go into solution so has no measurable ph. Ethanol does go into solution, however the process of ethanol entering solution/mixture with water makes it impossible to measure the ph of ethanol on its own, so we're left with the ph of the ethanol/water solution which is ~7.9 or very slightly basic, but not more basic than water and other things that we typically consume.

^^^ We are doing this in my Fuels and Lubes class at VU lol..... I know that is completely off topic but just throwing it out there lol

 

[CountryBoy19]

^^^ We are doing this in my Fuels and Lubes class at VU lol..... I know that is completely off topic but just throwing it out there lol

Doing what? Putting gasoline into solution with water? Putting ethanol in solution with water? Measuring the ph of ethanol/water solutions? Or all of the above?

 

[mdmayo]

Hmmm... degree in chemistry... I don't mean to insult you, but it probably will... in order to have a ph does something not have to be in aqueous solution giving up H+ or OH- ions?

Gasoline doesn't go into solution so has no measurable ph in the conventional sense. Ethanol does go into aqueous solution, however the process of ethanol entering solution/mixture with water makes it impossible to measure the ph of ethanol on its own, so we're left with the ph of the ethanol/water solution which is ~7.9 or very slightly basic, but not more basic than water and other things that we typically consume.

I'm not insulted in any way. You are correct, there is no direct way (conventionally) to measure pH in either gasoline or ethanol as stand-alone non-aqueous liquids. My presentation was merely a simplification for the sake of this discussion.

However, there are methods to determine the pH of both. BP, Conoco Philips and a whole slew of other labs do it every single day. See this abstract for a glimpse at one of many new methods, and look into the concept of the "Unified pH scale" (not so new) which has was developed on the basis of the absolute chemical potential of the proton. This scale applies to liquids, gases and even solids, so that direct measurements are possible.

 

[Tula47]

Doing what? Putting gasoline into solution with water? Putting ethanol in solution with water? Measuring the ph of ethanol/water solutions? Or all of the above?

Both, then testing pour and cloud point

 

[HavokCycle]

i was once of the mindset it was a good thing, and i'd buy it despite the poor economy. 'someone has to buy it, or it'll disappear.' since then i've had a change of opinion, notably because of shale-oil, and importantly, because WE'RE BURNING OUR FOOD

there will come a time when the world will have to get off oil but that time is not now, the technology just isn't there yet. soon, but not yet. we NEED research into alternative fuels absolutely, but technological progress comes from free-enterprise and NOT gov subsidies.

 

[mdmayo]

And there is still debate over the actual pH value of ethanol. I've seen values in literature from various sources within the fuels community as high as ~7.9 (conventional aqueous solutions, ) to ~ 1.1. The Unified pH numbers vary as well, from ~1.2 to ~5, still acidic.

 

[CountryBoy19]

Both, then testing pour and cloud point

Just pour and cloud point? What is the goal of your research/testing?

I went to Rose-Hulman and did privately funded biofuels research for 2 years. We did the whole deal of ASTM testing for fuels... Cleveland Cup flash/flame point, viscosity, all that stuff... I was one of the mechanical engineers on the team so I tried to stay out of the chem lab. We got to build up and operate the test engines. Anything from 20cc 2-cycle leaf-blowers to a 350 V8 with a 14.5:1 compression ratio (had to run special bearings & oil-pump, geared race-car starter, and special ignition on that one)... 14.5:1 is insanely high for a gasoline engine but we were running pure alcohols (ethanol, methanol etc)...

 

[Gabriel]

Don't know why it's cheaper right now, but from a few guys I know with flex fuel capable vehicles they say that E85 is less efficient than if they filled up with regular 87 octane gas.

I was one if the people for our departments "testing program" for E85 when they were considering using it in all the flex fuel vehicles. My mileage immediately went from 11-12MPG down to 4-5MPG. I went from fueling up every other day to sometimes having to get fuel twice in a shift.

 

[hooky]

If Ethanol has a ph of 1.5, wouldn't shine or everclear just burn a hole right through your mouth before you could swallow it?

 

[mdmayo]

Nope. Everclear/Shine is only 75- ~95% alcohol by volume, not 100%. It takes very little water to dissociate those Hydrogen (H+) ions, 5% is plenty, 1% is probably sufficient (or at least really close). It probably comes out at around a 7.5 - 7.9 just like ethanol in conventional pH.

 

[remauto1187]

Have a degree in chemistry? I do. Ever do any real-world environmental cleanup? I have for 20 years. Are you an ASE certified Automotive Technician? I am in fuel delivery systems.

Yes, ethanol is a solvent, as is gasoline (and many of the individual compounds it is made of). Ethanol is also an acid, gasoline is not. Acid < pH7.0 < base. Ethanol's Ka = 15.9; pH = -Log(15.9) = 1.20. Clearly a very acidic liquid. Gasoline's Ka = 0; pH = -Log(0) = infinity. Clearly non-acidic. One of the biggest environmental concerns about ethanol is that due to it's acidity it corrodes metals and dissolves rubber. These points lead to shortened lifecycle of fuel injection systems, storage/supply systems, and pipeline delivery.

Results?
Environmental: Leaky underground storage tanks, pump islands, and pipelines that do contaminate soil and groundwater.
Automotive: Premature failure of the injectors and seals in Flex-Fuel systems, not much of a concern in ethanol-only systems.

You are speaking from an indefensible position.

no...I am speaking from a 2003 Chevy Tahoe FFV that does NOT have any fuel system leaks kinda position. No ethanol eating a hole through my fuel tank either. The stuff is great for fuel system and engine deposit cleanup standpoint. Completely useless from a economical standpoint AKA MY Wallet.

 

[mdmayo]

Ask yourself why it's cleaning so well, as it undeniably does. Premature failure isn't acute, and following the manufacturers recommendations for use of dinofuel very greatly reduce the breakdown. Never seen one catastrophically fail. Glad yours is still performing as intended.

 

[CountryBoy19]

Nope. Everclear/Shine is only 75- ~95% alcohol by volume, not 100%. It takes very little water to dissociate those Hydrogen (H+) ions, 5% is plenty, 1% is probably sufficient (or at least really close). It probably comes out at around a 7.5 - 7.9 just like ethanol in conventional pH.

And the problem has just been solved... use hydrous ethanol... cooler running engine, dissociates the Hydrogen ions making it relatively neutral pH, and significantly cheaper to manufacture...

Although, from my casual reading it appears that some part of the use of hydrous ethanol for fuel is patented... not sure the details...

 

[Tula47]

Just pour and cloud point? What is the goal of your research/testing?

I went to Rose-Hulman and did privately funded biofuels research for 2 years. We did the whole deal of ASTM testing for fuels... Cleveland Cup flash/flame point, viscosity, all that stuff... I was one of the mechanical engineers on the team so I tried to stay out of the chem lab. We got to build up and operate the test engines. Anything from 20cc 2-cycle leaf-blowers to a 350 V8 with a 14.5:1 compression ratio (had to run special bearings & oil-pump, geared race-car starter, and special ignition on that one)... 14.5:1 is insanely high for a gasoline engine but we were running pure alcohols (ethanol, methanol etc)...

We were comparing the cloud and pour point of different fuels to diesel #1 and #2, bio diesel, E85, and gas