Does Acetone Addition to Fuel Lower Consumption?

[djmeier1]

Thanks for the effort, Dabooj. I am presuming that this result will show to the scientists in the group that acetone use represents false hope. Jetta Jake are you out there?? Nick??

 

[JettaJake]

Hot 'lanta! real data!!

I don't have pretty pictures, but I don't have a good way to get my results off of the computer yet.

You can always use screen capture (ALT-PrintScreen) and then paste that into Irfanview or some other image viewing/editing application. Irfan can convert between bmp/jpg/gif/tif/u-name-it file types and yet another reason Irfan (www.irfanview.com) kicks such total butt is that you can install it at work even on coporate systems where they normally don't let you install anything on their IT-managed, vanilla PCs (no admin access).

Anyway, great job running the tests! The results are certainly in line with my expectations. Let me suggest running pure acetone if you revisit these tests at a later date. Don't think it's feasible to run elevated tests, but at elevated temperatures, you might get a different result. I'm assuming these tests were run at RT.

Don't know about false hopes, but these data sure don't lend any support to the anecdotal evidence. I plan to fill-up Jake this weekend....think I'll snag a couple oz of acetone from the lab to add to the 5 gal of B100 I will be spiking into the tank

diesel does it -- be careful on the roads this weekend TDI'ers!

JJ

 

[JettaJake]

assuming you go that route, be sure to get the irfan plug-ins, too ^_^

 

[eb2143]

What percent acetone is your average nail polish remover? The one I found laying around was, "Nail Polish Remover enriched with Protein!!" It seems to have a lot of other stuff in it besides acetone, including water.

 

[TDIJetta99]

What percent acetone is your average nail polish remover? The one I found laying around was, "Nail Polish Remover enriched with Protein!!" It seems to have a lot of other stuff in it besides acetone, including water.

Don't put the nail polish remover in your fuel tank, LOL. I didn't know acetone would mix with water.. Protein huh? I guess that's to keep your fingernails from drying out? The acetone we're using is what you find at most hardware stores in the paint section. I'm not too sure what the exact percentage is for the nail polish remover.. The can of acetone I have doesn't say that it contains anything else, so I'm assuming it's straight acetone, unless someone here knows otherwise..

 

[nicklockard]

It varies so much brand to brand. Examples:

40% acetone/ 40% mineral oil 20% other
30% acetone/ 20% water/X% emmolient...and so forth.

Suffice to say that as a source of acetone it isn't the best.

PS Acetone mixes fully with water (is fully miscible, in all ratio's) which is one of the things that makes it *not good* in diesel.

 

[Ernie Rogers]

Okay, why were we measuring surface tension?

I'm not trying to be disagreeable, I think measuring surface tension was a good idea-- but, why were we measuring surface tension?

I think we had the idea that lowering surface tension could improve atomization. So, maybe high vapor pressure improves atomization? I think if Nick or other number-cruncher here will calculate the "relaxation time" for heat-up of a droplet, you will find it to be under one millisecond. That's fast enough to cause a droplet to possibly blow apart. So you could get the effect without having lower surface tension. I know I'm reaching here, it needs a more careful analysis.

I just posted a long thought on the nail polish remover thread some may want to look at.

Ernie Rogers

Thanks for the effort, Dabooj. I am presuming that this result will show to the scientists in the group that acetone use represents false hope. Jetta Jake are you out there?? Nick??

 

[nicklockard]

Thanks for the effort, Dabooj. I am presuming that this result will show to the scientists in the group that acetone use represents false hope. Jetta Jake are you out there?? Nick??

Dave, I was never sure what surface tension would tell us. I'd say it's far from definitive, much like my dyno run. Too early to draw that conclusion. Let's revisit some of Ernie's earlier thoughts from page two of this thread:

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.

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.

Let's also pull Ernie's thoughts from the nail polish thread into this:

My wife has a bottle of "average" nail polish remover. The description begins-- "Non-acetone ..."

The ingredients begin-- "Ethyl acetate, alcohol, water, blah, blah, ..."

I think the original, "average" nail polish remover was pure ethyl acetate and that would dry out hands, so they added some junk later. I didn't know they ever put acetone in.

Now, let's ponder this question one more time-- does acetone (or other volatile organic) add anything to mileage, i.e., engine efficiency?

Hmm, does ANY additive work? How about Power Service, does that improve mileage? ---Well, maybe. It contains ethers that raise cetane a lot. So, some additives will raise cetane, and that can improve mileage for an engine that injects fuel a little bit late. We think that biodiesel can improve mileage at low percentages, and I think that may be connected with a faster burn as well as a slight increase in cetane.

Hydrogen gas injected at low percentage into the intake air is reputed to boost mileage, and some people are certain that "humidifying" the air improves mileage.

Most of these benefits are probably real, and they generally add no extra energy. We know that diesel engines have combustion efficiency of about 98% or better, so no chemical additive can improve combustion efficiency enough to notice. The remaining factor is timing.

Remember that increasing injector nozzle size also tends to improve mileage by allowing the burn to complete earlier, with a slight reduction in combustion efficiency. Smaller nozzles improve emissions by increasing combustion efficiency but sometimes hurt mileage.

So, I think that's the tentative answer: If your engine is set to inject a little late, then any fuel additive that shortens ignition delay (raises cetane) or allows combustion to complete earlier will improve your mileage. A timing advance may also improve mileage. Engine experts in the forums could give more info on this topic.

Ernie Rogers

Following comments color coded to Ernie's original thoughts:

We know that in certain parts of the rpm band of the Tdi motor, the presence of the swirl chamber is there strictly to improve fuel/air mixing. I think at other parts of the rpm band there is insufficient time and the air has too high of a velocity to mix by swirling (and must depend on diffusion-limited mass transport(?)) The swirl chamber is there to minimize emissions without sacrificing power too much--if I'm understanding its purpose correctly (hope someone corrects if mistaken.)

How this relates: smaller droplets will reach higher velocities, droplets which boil to gas phase will have higher diffusion rates. Both effects increase fuel/air mixing. The swirl chamber is like a blender. It mixes by (velocity) agitation/shearing.

If you have two otherwise chemically (nearly) identical substances with the same energy density and burn properties, the one which boils at a lower temperature should vaporize and ignite at a lower temperature: in the case of a diesel engine that translates into burning earlier, which is known to do more useful Pressure-Volume work upon the piston because of *when* it exerts pressure. But, boiling point of neat diesel is very high. My benchtop lab equipment won't go that high. I can't think of a safe way to test b.p. without access to a Differential Scanning Calorimeter. Our lab does not have one.

This proposed qualitative experiment deserves looking into more. Maybe we can tell something about fuel behavior from that. *this comment relates to Ernie's last post above also.*

Also, maybe I'll have some better data for you in a week.5

 

[djmeier1]

I think that we are lucky to have a few very smart people willing to take the time to bring guys like me along. Thanks!

 

[JettaJake]

DSC isn't a horrible idea. I even have access to one but no high pressure cell available for running liquid samples. Just guessing, but I have big doubts any noticable difference would show up.

 

[bobgolf2004]

Here's a link to an interesting (and unbiased) report on acetone:

http://www.kettering.edu/news/archivedDetail.asp?storynum=406

 

[bobgolf2004]

For what its worth (you get what you pay for), I believe, at best, acetone has an ability to restore mileage, rather than increase it through its solvent properties. But you can get biodiesel to do that!

 

[nicklockard]

Here's a link to an interesting (and unbiased) report on acetone:

http://www.kettering.edu/news/archivedDetail.asp?storynum=406

Excellent! Thank you.

 

[TDIJetta99]

That's a great article.. It would be interesting to see the same tests with a small diesel.. That GM 3800V6 they used gets awesome fuel economy even in a big LeSabre. It an amazingly efficient engine for its size. I got about 28mpg when I had my lesabre.. I got over 30mpg with a cavalier that I transplanted a 3800 into as well. We have a few customers at work with 3800 cars that get very good fuel mileage too.. They should try tests like that with an engine that's known to get less than average fuel economy, or on an engine with 150,000 miles on it.. I'm sure the engine they used was like new, if not new when they started testing with it..

 

[LurkerMike]

Here's a link to an interesting (and unbiased) report on acetone:

http://www.kettering.edu/news/archivedDetail.asp?storynum=406

How much Acetone did they add? 10%? or .000000001%? Or both?

We need to know if he used the "magic" ratio.

Also, it is possible that Acetone does NOT help a gas engine at all. But this would not necessarily tell us anything about what it would or would not do for a diesel.

 

[JettaJake]

Contacting Kettering U. Auto Emissions Group

Copied this to Prof Davis as well --- hoping we'll see some interaction, get more info....maybe develop a rolling test bed ^_^
-----------------------
Greetings Ms. Hibbard,

The topic of acetone doping increasing(?) fuel mileage has been discussed practically ad nauseam in the VW TDI diesel forums. Few conclusions have been reached but some of our more inquisitive members have worked at getting some real data to support or deny the mileage boost claims. These attempts go well beyond just running acetone in the tank and tracking (apparent) mileage, but in general, the data acquisition attempts have met with limited success.

As you will see if you review the attached link to one acetone thread, many more members have offered up anecdotal evidence or testimonials for and against. This one particular thread goes on for pages and while a number of the posts are primarily nonsense, some real effort has been shown to get to the root of these recurring claims about acetone benefits.

Personally (and as a PhD chemist), I doubt there is any beneficence to using the stuff but show me the supporting data and I could/will change my tune.

http://forums.tdiclub.com/showthread.php?t=128493

Site homepage: www.tdiclub.com

In any case, I am writing in hopes of getting Dr. Davis and his students to share more of the nitty-gritty details about the work briefly recounted in your article. I can safely say that no detail is too small for us diesel diehards (and mileage fanatics!); we really want to know.

Also, if there is any desire to apply testing to real world platforms, Greg will surely find plenty of willing, conscientious volunteers within the TDI community. Hope to hear from you or the Prof soon and thanks for publishing your article.

TRH
Pratt & Whitney Aircraft - East Hartford CT
Materials & Processes Engineering Group
Phone: (860) 55xxxxxxxxx
Fax: (860) 75xxxxxxxx
e-mail: txxxxxxxxx@pw.utc.com

 

[dieselgeezer]

Acetone Boosts Cetane Number

When I was in graduate school more than 30 years ago, I became interested in fuel composition and octane, since I was burning small amounts of waste solvents in my gas tank as an alternative to dumping them in the sewer system. I found engineering texts with tables of experimentally determined octane and cetane numbers for various organic liquids. A lot of this data was developed by Charles Kettering's (developer of tetraethyl lead additive) group at General Motors in collaboration with Shell Oil. I am a bit surprised that some of the engineers on the forum haven't found this data. Acetone was very low on the octane list and very high on the cetane list--truckers were then using it as a cetane booster. This probably relates to the reactivity of the keto group, which lowers the activation energy for ignition. Consequently, I avoided using it as a gasoline additive. As I recall there were other ketones (e.g., methylethylketone) that had similar properties. On the other side of the fence, alcohols (methanol, ethanol, propanol) and ethers (MTBE) have high octane (>100) and are excellent octane enhancers. Low octane generally means high cetane and vice versa. The additive effect is not proportional but it does trend in the same direction.
If a boost in cetane value increases fuel mileage, then it would not be unreasonable to expect some increase in mileage from addition of acetone or any other cetane enhancer. Whatever the mechanism, a similar effect might be obtained using a less volatile ketone such as MEK or diethylketone. As for questions that have arisen in regard to solubility, acetone is completely miscible with hydrocarbons, such as those found in diesel. However, it is also soluble in water and a mixture of acetone and hydrocarbons will form two phases if water is present.

 

[eb2143]

2001 Jetta TDI
Consistent @ 48 mpg over 145,000 miles
added 2.5 oz of Acetone to full tank:
NO CHANGE IN FUEL ECONOMY OBSERVED

 

[JettaJake]

Acetone is now a verbotten topic @TDIClub per BKmetz -- lock it up, BK

 

[Powder Hound]

Y'know, JJ, you could have just let this 2 year old topic die a natural death, as it had been on the way to doing.

 

[ronbros]

I dont know if IT helps MPG, but in mine it does start better in cold weather, smoother and quieter!!
Ron

 

[Da~da~da]

Y'know, JJ, you could have just let this 2 year old topic die a natural death, as it had been on the way to doing.

roflmao... you would think! Pandora's box has been reopened after more than 2 years! sigh

 

[Suns_PSD]

I tried the Acetone thing in my powerstroke a few years ago.

It makes a huge difference in the sound of the engine greatly reducing clatter similiar to Propane and Hydrogen (which I've also experimented with). I'm pretty sure that the noise difference is do to accelerated combustion resulting in less diesel delay.

I gained about a 1/4 mpg on a truck that got about 16 mpg at the time.

If injection timing was not ideal on a particular motor it is reasonable to expect an increase in performance and mpg using Acetone if the timing started out being overly retarded.

I should add that I was trying out some other high power mods and I blew a HG on the PSD while it had Acetone in the tank. I don't know if it was a related problem as the truck had over 500 rwhp at the time.

 

[JettaJake]

Y'know, JJ, you could have just let this 2 year old topic die a natural death, as it had been on the way to doing.

ya, but it was on my subscribed list and I like kicking sleeping dogs

 

[Da~da~da]

ya, but it was on my subscribed list and I like kicking sleeping dogs

Where's PETA when you need em

 

[BKmetz]

Acetone is now a verbotten topic @TDIClub per BKmetz -- lock it up, BK

lol...

Done deal.