Jump to content
Sign in to follow this  
fleebut

E100

Recommended Posts

For a good read on dedicated ethanol engine: http://www.epiphergy.com/uploads/Acr21.pdf

 

It’s a 2004 France study. Some points:

 

Cold start problem will need a solution

 

9% CO2 reduction with ethanol engine

 

12:1 compression a good compromise as higher compression incur too much mechanical friction loss.

 

Connecting rods need to be stronger as well as crank bearings

 

DI will provide max benefit

 

Turbo charger has to be tailored to ethanol

 

Small engines with high boost the best

 

Final drive gear ratios for high torque ethanol

 

Valves suffer more heat as no impurities within fuel to insulate valves, nickel alloy best?

 

Spark plugs suffer similar, but commercial plugs available to do job

 

Exhaust temperatures lower, yet plugs and valves get hotter

 

Lower exhaust temps suffer cat lighting off quick

 

Converter should be customized to ethanol exhaust

 

Avoid rubber in fuel components use Viton instead

 

Copper and magnesium suffer, steel and stainless good

 

Aluminum good, yet if laying close to stainless, ethanol will magnify the galvanic corrosion between the two dissimilar metals.

 

Hydrous ethanol more chemically active

 

Current blending of ethanol requires lower volatility gas for EPA vapor pressure regs.

 

My conclusion:  Current practices of ethanol blending with gasoline, makes gas look and operate better at the cost of making ethanol look bad. Ethanol fuel shines brighter, operating best on its own. Marine applications for 100% ethanol particularly good. Ethanol as its own fuel lowers CO2 emissions by 9% during combustion as compared to petrol and that’s before all the natural CO2 cycle of the field plant growth.  The cold start problem shouldn’t be a show stopper, but something to experiment and develop. May the DI help as injecting fuel in hot compressed air chamber?

 

Share this post


Link to post
Share on other sites

is there any way of "denaturing" alcohol with out compromising it by adding dirty old gasoline? ;) 

 

I was under the impression that true "e100" would have to also pay the very high state "excise tax" that any bottle of whiskey would...  By "denaturing it", it is able to avoid these taxes as it is unfit for human consumption...

 

Is there any way to denature it with out using petro-gasoline?

Share this post


Link to post
Share on other sites

I think, as far as the tax man is concerned, anything which renders it unfit to drink can be used as a denaturant - methanol, isopropanol, benzene, pyridine, bittering agents, etc could all be used.

 

Gasoline is used to denature motor fuel ethanol because a) it's already close at hand, B) relatively cheap, c) aids cold start issues, etc.

Share this post


Link to post
Share on other sites

This is true Corey- even a "top engine Lube" that is poisonous might qualify. The BATF and IRS would have to oversee legislative changes however- as the blender credit does not apply to any ethanol that does not have a significant (IE 15% or more) gas in it. Of course if the blender credit goes away these engines become even more critical for success as the thermal efficiency climb to 42-45% percent these engine offer would be necessary to compete with gas most of the year. Even though a dedicated engine would not be able to use gas- it still must compete or gas engines will be sold ILS gas- similar to the relationship of diesel engine purchase vs gas in light duty applications.

Share this post


Link to post
Share on other sites

There have been several studies and testing projects done in the last three years to show mid 40's on Brake Thermal Efficiency.  This offers a 30 percent reduction in CO2 over gasoline and 15 to 20 percent compared to diesel.

 

Gasoline has 85 identified organic compound from Benzene to Toluene, ethanol has 10, this would be a huge health statement.

 

E85 only engine could be 13 to 1 compression with E98 only being 15 to 1 but many things like direct injection to get the full benefit of the Latent heat, introduction of cooled EGR, variable cam timing are all things to consider in what the approach may be.

 

I think it would be best for now to stick with E98, for some safety benefits, having a dirty burning fuel will help in detecting a possible fire.  Just remember the few pit fires at Indy last summer, the visible flame wasn't because it had clean burning ethanol.

Share this post


Link to post
Share on other sites

I agree on the need for a "dirty fire". Just yesterday a lady lost control, hit a concrete barrier, and then slammed into an ethanol tanker here in WI. She did not puncture a pipe or the tank itself (so no leak) but imagine a daytime invisible blue fire on the 4 lane hwy this occurred on- no one would know it was there until they felt the heat- then it is too late, Firemen approaching a scene have a saying something like- watch the "blue canaries" (meaning state troopers) to see if they are standing, running backwards, rolling on the ground, or otherwise indicating heat/blast.

Share this post


Link to post
Share on other sites

I have multiple SAE paper for reference but this link is of interest as the move towards direct injection becomes more popular and cost effective.  One other key benifit when looking at direct injection is that ethanol still offers low particulate emissions while the trend goes up for gasoline.

 

http://ethanolboost.com/LFEE%202008-01%20RP.pdf

 

You will find Dr. Heywood and others listed on this site referred to in many of the studies that look at combustion efficiencies with ethanol.

Share this post


Link to post
Share on other sites

Ethanol good at reduced particulates and micro particulates so unhealthy. Diesel even wants ethanol mixed in for that reason. CO also greatly reduced as compared to gasoline.

 

Looking at a Jordanian study 3/10/2010 ISSN 2040-7467 on experimenting with alcohol fuel as an additive. They mentioned the mix of hydro carbon brew in petrol and the difficulty in controlling gasoline behavior. Impurities of sulfur and come international oil companies add lead or phosphorous. Doesn’t sound like a highly controllable fuel for pollution control?

 

The linked study at beginning of postings had E10% with high vapor pressure than plain gas. A chemical phenomena as higher concentrations E85 much lower. This higher vapor pressure, upon E10, the reason lower grade of gas co-partnered. EPA has strict regs on vapor pressure. As Outlaw posted, this lower grade of petrol will on it’s own cut down gpm. Isn’t that a hoot. E10 gets blamed for lower gpm, when mostly due to the lower grade of petrol blended with it. Doesn’t hurt blender whom may want to give ethanol a black eye and besides makes a lower cost product combination. Low cost ethanol with low cost petrol.

 

That Jordanian  study experimented with many blend concentrations upon a test engine. Interestingly for efficiency, brake fuel consumption flat for low rpm’s and took off after 1,700 rpm. This (would guess) due to changing direction of mass of piston upon high velocity and pumping efficiency. Also, thermal efficiency impressive for E15 (the highest blend) at this 1,700 rpm spiked close to 45%. All the other blends including E0 and E12% about 38% at this rpm. The study conclusion “It is obvious that 15% ethanol gives the best overall performance”.

 

Spotted the political side of the Jordanian science report….how they discuss good and bad and reference other science studies with much conjecture aimed at giving environmentalist ammo to stop corn ethanol…..their biggest fuel competitor. Politics upon science reporting, nothing new. Really watch out when the scientist urge population to shut down discussion and form a consensus. That’s not science….that’s politics.

 

Share this post


Link to post
Share on other sites

They like for you to use gasoline to denature fuel, but it isnt the only thing. The head and tailings of the run are unfit to drink, unless you really really enjoy a headache at the least.  You are required to denature alcohol that is used on the public roads, and also pay road tax on it which is usually less than the tax credit you get per gallon for making the stuff. If you use ethanol in your generator at home, in farm equipment, or in some other off road use you dont need to denature it no pay tax but you still get the tax credit for making it.

 

They would have problems with the exhaust valves heating up in a boosted application on a small engine, its typical for need better valve material in boosted engines. Boosted engines also require more fuel than a naturally aspirated engine making the same power, the lower compression ratio needed hurts bottom end torque when there is no boost, such as at cruise rpm under low load. It needs the boost to get the cylinder pressure up and the boost is not available at low rpm unless you limit the size of the turbo, or run two dissimilar sized turbos and taht adds complexity and expense. Less torque means more fuel to make the power needed, so I tend to gravitate towards larger NA engines running low rpm eg. 1500-1700 rpm cruise but with 6000 rpm capability. Getting a 2.0L to power up a 7% grade at 1700 rpm without downshifting or going WOT would be difficult unless it was in a very, very light vehicle. Too small an engine will cause it to work much harder to achieve the same work, thus it will use just as much if not more fuel than the larger engine that loafs along.

 

I build big engines because I like to have fun with them and mileage is a close second to having fun. About the smallest engine I will mess with is a 3.8L Buick, and since I have some of them now they will probably get some work. If I want all out power and fuel consumption is not as big of an issue, then I will turbo or supercharge it as soon as I can afford it. :) France likes small engines because the roads are small, relatively flat, and most of the population lives in an urban environment. In our stateside urban areas we can utilize smaller engines because they are not required to work very hard to move from one place to another at low rpm and low speeds. The vast expanse of the great plains and the mountains on either end of it are quite different from an urban area (particularly France and Europe) and those who live there would benefit from a larger displacment as opposed or in addition to boost.

Share this post


Link to post
Share on other sites

Oh, you configure a torque-y big bore engine with carbs, high compression, advanced timing and low ratio low rpm cruise you will be happy with mileage.  Yes, I agree the turbo will hurt mileage with most performance throttle plate engines.

 

But, a step up from that, at a compromise ....a small turbo engine  putting max output all of the time as the engine is underpowered for the task. Remember the hyper milers whom can improve mileage 1/3 to 2x by full power bursts? All, throttle plate engines run at max torque and efficiency upon wide open throttle up to 1700-2000 rpm....then shut it off and coast. Engines efficient operating upon this band. The reason hybrid so complementary to this  efficiency.....meaning run your small IC engine at this utmost efficiency spectrum all the time and allow the battery to take the slack up.

 

The turbo is great for diesel ignition engines. Sure wish ethanol could support the diesel cycle.  Ford plans on operating their Ecco engine sometimes upon diesel ignition during optimum conditions. They have a great technology to play lots of games with.

 

As I understand your planing on running straight ethanol? Or E85? Ethanol is a great race fuel. Wish more would rise to the mpg challenge and get better notice. Push innovation, technology, etc. to the high mileage challenge. 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this  

×
×
  • Create New...