Does Acetone Addition to Fuel Lower Consumption?

[Ernie Rogers]

Boiling point of a solution?

Hi, Nick,

Direct-injection diesels are unique in the kind of two-phase combustion going on. If the burn rate is limited by fuel-air mixing, then fuel breakup and evaporation may not have much effect. But, if droplet evaporation is the limiting process, then factors that affect that will definitely affect the burning rate and combustion efficiency. BOTH low surface tension and presence of a low-b.p. component will promote droplet breakup and consequently the rate of evaporation.

Now, how do you measure "boiling point" for a solution? Help me with the term-- differential thermography? You look for the steps in the curve, each one is a "boiling point."

Now, is this the right thing to measure? Probably not. What would you see if you drop the liquid onto a warm plate? If it foams up at a certain temperature (like soda pop), then I would say droplet breakup would have occurred. What do you think? I'm guessing. Heat and mass transport rates should be looked at to decide if the acetone (or any other light component, for that matter) can "blow apart" a droplet.

Ernie Rogers

I agree with Dave. Surface tension can not be correlated to fuel economy(edit--to my knowledge.) Surface tension and b.p. depression are useful data to have, but neither can be correlated to fuel economy inside a diesel engine(?) The dyno test (as proposed previously) against a control sample and measuring fuel consumption with a graduated cylinder will be more definitive (elucidate causation rather than correlation.)

I can still try and do b.p. depression. I'll do it after hours in test tubes in a heating block. We're finally settling down here now that the hoods are installed.

My edits in italics.

 

[nicklockard]

Boiling point depression is a well known phenomena having a bulk colligitave property effect. All I have to do to find a boiling point depression is stick neat diesel in one test tube, diesel/acetone solution in another, and place them both in the same heating block, using a thermocouple/digital thermometer to observe the temperature at which they boil at standard pressure--1 atm. What that possible temperature spread means (in either a relative ratio or absolute sense) at very non-standard temperatures and pressures found inside a diesel engine prior to commencement of ignition is harder to answer...

But it gives a starting point and something for us to mull over. The dyno runs will give a better handle on real world effects, if any, IMO.

We have to keep in mind that diesel fuel itself is a solution of about 25 or so different molecules and will have an extraordinarily complicated phase diagram (probably can not be predictively mapped without the aid of a super-computer)...so adding one more component to it such as acetone is unlikely to change the phase behavior of diesel fuel in any predictible way...which is why we simply need real world consumption figures plotted against known loads, for known time and temperatures, IMO.

 

[nicklockard]

Well I won't be able to make the Diesel Dyno days on the 15th as I will be helping to pick up my younger brother's new (to him) 2005 Jetta PD-Tdi in Kennewick, Washington. But, I contacted the shop owners and left an inquiry. Hopefully they'll be copacetic with an acetone/diesel show down.

 

[AlaskaRanger]

Acetoned diesel

I thought esp. JettaJake would appreciate the observation that

acetoned

and

anecdote

are anagrams....

my highly effective contribution to this discussion......

 

[djmeier1]

Some time ago, I agreed to run a tank or two with ascetone to see what result it might produce in fuel efficiency in my vehicle, I ran two, but I mismeasured the ascetone added to the first tank. I was inserting it with a chicken baster and I misread a 1/2 ounce mark in the glass tube as representing two ounces. On that tank, I found no improvement at all (47.5mpg).

On the second tank, I discovered the error and added 2.5 oz. of ascetone before filling. This trip was a round trip from Madison to Minneapolis and return. It was run completely on the interstate where I maintain a constant 80 mph on cruise control, except as may be required by construction or traffic. Also, I am a pretty agressive driver and make no concessions to the rules and recommendations of the high mileage fanatics. Therefore, I was surprised to find on reaching Madison and fueling that I'd gotten 51.15 mpg. At that high speed, I would normally see a reduction in mileage to about the 44mpg area.

Now I offer this as anecdotal only. I don't wish to get into a discussion with scientific process purists over whether wind speeds and directions, ambient air temps, tire inflations, etc. were constant. I will not take time to defend any conclusion. All I know is that I achieved mileage that I'd never seen before and without reducing at all my demands on the engine.

I intend to continue adding the ascetone and monitoring the mileage. Based on this limited amount of data, however, I'm at least intrigued by the possibility of enhancing mileage with ascetone additive.

 

[JettaJake]

I thought esp. JettaJake would appreciate the observation that

acetoned

and

anecdote

are anagrams....

my highly effective contribution to this discussion......

I have always enjoyed mispronouning it as two words as in.... "pass me that ace tone squirt bottle..." A common reply would be... "huh?"

 

[nicklockard]

Updates regarding dyno

I spoke with Angela at Fast Specialties shop in Vancouver (just over the border from us.)

They're very receptive to doing a fuels test. Cost is $95/hour. Working fast, I can do one run in 20 minutes, purge and swap in 20 minutes, and finish the acetone run in 20 minutes.

So, I'm going to need $95 for the dyno test and a Mityvac for purging the pump. I've got the first $40. Contact me if you can help and want to contribute something to gathering this data.


The approach is very straightforward (I'll have a helper):

1. Bring engine up to full operating temperature prior to arriving. Prefer all components to be as heat-soaked as possible. Temperature checked by vag-com on laptop. 1a. Record temperature as vag-com log file throughout run.

2. Pull lines from fuel filter and stick them into a 1L graduated cylinder filled with fuel. Strap car onto dyno and get into high gear.

3. Dyno operator will load engine down to simulate predicted loads at that road speed (aero, rolling resistance, mechanical friction, etc...)

4. Mark time at start of run. Simultaneously, record level of fuel.

5. Stop run when fuel is nearly consumed. Record time and fuel level.

6. Shut down engine.

7. Purge injection pump with Mityvac: sucking from return and loading in test fuel. (If I knew the internal volume of the IP and lines I could avoid this by simply adjusting the dosing ratio upward appropriately and allowing time to mix well.)

8. Start engine and load heavily for 3 minutes to heat soak engine. Once engine is at same temperature of previous run, repeat steps 1a through 6. If there's a ten or fifteen percent gain in fuel economy to be had, then the second run will be noticeably longer than the first.

9. Perform time/speed/miles calculations and report back to you guys with numbers.

Now, I need more information from you who are interested: what type of fuel should I use? "Good" Shell fuel or "bad" Astro fuel? What would make a more valid test, in your opinions? I don't have enough time or $ to run multiple fuel grades or brands, so one will have to be chosen. Also, what dosing rate do you want? 3 oz/10 gallons?

 

[jackbombay]

What about the fuel in the fuel filter, when you purge you'll need to do something about that. Or will you just add extra acetone in proportion to the volume of the fiter?

 

[nicklockard]

The fuel filter will be out of the loop for the duration of the tests. The fuel will be drawn from and returned directly to the graduated cylinder (I'll make tube extensions so they can reach to the bottom of the cylinder.)


Edit for brain fart.

 

[jackbombay]

The fuel filter will be out of the loop for the duration of the tests. The fuel will be drawn from and returned directly to the graduated cylinder (I'll make tube extensions so they can reach to the bottom of the cylinder.)


Edit for brain fart.

Cool, make sure to use very clean tubes

Do you have a paypal address I can send a little donation to?

 

[nicklockard]

PM sent. Thanks!

It'll be nice to have some hard data.

I'm still looking in to how to do a b.p. test safely. I've prepared test tubes of dosed and un-dosed control samples using both Astro and Shell fuel, but I need to give some thought to safeguards: diesel boils around 200-350C I'm not even sure my heating blocks go that high!

I wish I had access to a DSC (differential scanning calorimeter) or TGA (thermogravimetric analyzer.) Anyone, anyone?

 

[djmeier1]

Mail or Paypal? Address? Dave.

 

[nicklockard]

I don't have paypal (well, I have the cheapskate version which doesn't allow transfers):

Send to:

*omitted*

jackbombay, thanks.

 

[TDIJetta99]

I don't think it would matter which brand of fuel as long as you use the same fuel for each test.. I would think a 10-15% increase in economy will be noticed right away regardless of what fuel is used..

 

[djmeier1]

acetone

Nick, on your question as to how much to dose, I simply added 2.5 ounces to a 14 gallon fill. I was too lazy to calculate the ratio...and still am. I think your suggestion of three ounces per ten gallons sounds fine. We are kind of shooting in the dark, anyway. This test is really to determine whether any dosing provides a provable result. So, I'd rather give it a stiff shot than wonder, after a negative result, whether we'd dosed enough.

My check was mailed this morning. Thanks for doing this for us, Nick. Dave.

 

[nicklockard]

Thanks guys for the contributions: jackbombay, mdt, and djmeier1 so far (total not known)...as soon as we have enough for the hour and the vac unit I'll schedule this.

Anyone local want to lend us the mityvac?

 

[jackbombay]

Anyone local want to lend us the mityvac?

I'll be in P-town for the upcoming week and my good friend has one that I'm sure he'd lend out, but when you're done with it you have to drop it off at the right house... I might even give you accurate direction this time

 

[nicklockard]

LOL. That would certainly help!

Guys, I found this graph on one of the "acetone works, so does my mystery snake oil" websites"

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Figure 1:
Percentage MILEAGE GAIN when a tiny amount of acetone is added to fuel. The curves A B C show the effect on three different cars using different gasolines. Some engines respond better than others to acetone. The D curve is for diesel fuel. Too much acetone decreases mileage slightly due to adding too much octane to the fuel. Too much additive would upset the mixture ratio because acetone (like alcohol) is a light molecule and tends to lean the mixture.

So according to this we should dose at the peak of curve "D" at 1.5 oz/10 gallons.

Does it bug anyone else that there are curves with no data

 

[jackbombay]

So according to this we should dose at the peak of curve "D" at 1.5 oz/10 gallons.

Does it bug anyone else that there are curves with no data

I've been dosing at .16 Oz. per gallon, very close to what the referenced info says. The curves with no data are somewhat worthless, and frustrating at the same time.

 

[djmeier1]

Jackbombay, your .16 oz. per gallon appears to exactly hit the peak of the curve for diesels. How did you land on that number? Nick, it looks like .16/gallon is probably the best ratio, based on what we know. Consider me in support at that ratio.

Just moved the decimal point left by a digit, to prevent causing someone to greatly overdose. Dave.

 

[jackbombay]

Jackbombay, your 1.6 oz. per gallon appears to exactly hit the peak of the curve for diesels. How did you land on that number?

After reading that first article I thought I had recalled that 800 to 1 was the best ratio so I used that (.16 oz/gal), but after skiming the article again I didn't see that noted, guess I got lucky

 

[djmeier1]

acetone

You know, if there is truly a mileage gain to be had using acetone, then there has to be found a good way to handle and portion out the liquid. People will abandone usage, even in the face of gains, because of the difficulty in apportioning, avoiding spills on auto paint, etc.

I know this is premature, but I'm becoming convinced that I'm getting a mileage boost justifying continued acetone usage. If the testing to be done by Nick Lockard bears out the apparant benefits of its use, then what might be the recommended manner and equipment for handling?

I have wasted about as much acetone as I have used while trying to load a turkey baster from a one quart can of acetone. Several ounces have been spilled on the paint while transferring to the tank. The baster leaks on my hands and spurts when rotated, causing more risk than its worth. And, the thought of dealing with something like a shot glass or other measuring container (and a funnel) while standing at the pump is not at all attractive. Further, some have raised the spector of chemical deterioration of plastic in the fuel filler tube, although I can't see plastic in mine.

I think that I am coming to agree with those who have suggested pre-dilution of the acetone to facilitate safer and more controlled handling. But, how much dilution is practical? And, what type of container should be used? Acetone dissolves plastic, right? So, must it be a glass bottle? I really prefer plastic!! A fuel fill for me is generally about 14 gallons, which would require about 2.25 ounces of acetone. This amount, diluted at a ratio of 2 to 1, would provide four doses in a 1-quart container. At this dilution, is there a plastic quart bottle that will withstand the acetone?

I have a 1-quart bottle of "STA-BIL" fuel stabilizer. It is a neat design that allows graduated dispensing through the use of a separate 1-oz. chamber that you fill by squeezing the bottle, then pour from a long neck into the fuel tube. This would require seven squeeze and dispense cycles to dose the tank. And, of course, its plastic (TN/3203 HDPE)! But, perhaps it would work. What do you think??? If it worked at 2-1 dilution, what about using the nornal diesel additive as the dilutant, thus saving a second additive process???

If this sounds a bit like "stream of consciousness", that's because it is. But, I'm going to empty the old Sta-Bil bottle today and fill it with acetone to see what happens. Dave.

 

[jackbombay]

And, what type of container should be used? Acetone dissolves plastic, right? So, must it be a glass bottle? I really prefer plastic!!

I am using an old "Cheveron 2 stroke motor oil bottle" It is plastic and I put a dishsoap top on it so I can squirt the additive/acetone mixture into the tank and it has OZ marked on the side of the bottle. I filled the bottle half way with pure acetona nd left it upside down for a week with the dishsoap top and none leaked, I was satisfied.

 

[djmeier1]

Well, the "STA-BIL" bottle really works well. And, it does not have any apparant effect from the acetone. I'm happy with that. Later. Dave.

 

[RealMonster]

My main question is whether or not burning acetone is likely to be a bad environmental pollutant. Acetone isn't the nicest chemical in the world, but we generally handle very small amounts of it at a time. If we all start burning it our cars -- or even if I start burning it in my car, and get the occasional face full of exhaust -- what's that likely to do to my health and the health of the people and environment around me?

 

[djmeier1]

Realmonster, I agree that environmental effects need to be considered if acetone is to be considered for wide usage. But, if it is proven worthless as a fuel extender, the environmental study will never be warranted.

 

[RealMonster]

Fair enough, I suppose. Though maybe we should be asking the question the other way around. If it's damaging to health and environment, should we even be considering it as a fuel extender?

This is an interesting experiment in any case.

 

[JettaJake]

CH3COCH3 is very easy to fully combust leaving primarily CO2 & H2O and just a tad of CO.....not a big enviromental wart really...

Anyone check the BTU content? gal of acetone vs gal of reg diesel? I'd assume considerably less BTU's from the solvent. Specific gravity at 0.785 is pretty low.....okay, did the google thing...

more testimonials

139 KBtu gallon of diesel
124 KBtu gallon of gasoline (some say ~115)
_84 KBtu gallon of ethanol
110 KBtu gallon of butanol www.butanol.snakeoil.com/
xxx KBtu gallon of acetone? ~100?

MSDS for acetone

take a look at this advice/comment at "PESWiki" re acetone and there's even more grist for the mill there....

Acetone& Laws of Thermodynamics

anyway, i have no idea where this all goes....this stuff just keeps going and going....happy Easter ^_^

 

[nicklockard]

Jettajake, I agree your ranking of energy content is correct, given that acetone is a ketone.

As mentioned oft here and at other good sites and resources, combustion efficiency in a modern turbo diesel engine under nominal operating conditions is at or for all practical purposes at (damned near) 100%.

The one glaring exception is during cold start, which any engineer worth his bones will tell you. That is the only practical place I can see room for combustion improvement. Secondarily, if an additive causes the commencement of ignition to begin earlier in the crank rotation, the resultant P-V work done will be more effective, but there is very limited room for improvement here, I believe. Advancing effective timing too much increases NOx emissions and puts more stresses on engine components due to higher heat and pressure loads.

 

[jackbombay]

Secondarily, if an additive causes the commencement of ignition to begin earlier in the crank rotation, the resultant P-V work done will be more effective, but there is very limited room for improvement here, I believe.

Decreasing ignition lag will increase efficiency, that's what Power service and all the cetane boosters hope to accomplish, I've seen graphs associted with one of them that shows cylinder pressure vs degrees of crank rotation, with the cetane booster cylinder pressure rises faster resulting in better efficiency... supposedley.