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rebelman
Joined: 25 Apr 2006
Posts: 31
Location: North Carolina
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 Posted: Sat Apr 29, 2006 8:51 pm Post subject: Difference in e85 and biodiesel |
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| Does anyone here know the difference between e85 and biodiesel. My Uncle says that biodiesel is the way we should go instead of ethanol. I think that they are about the same. Does anyone know for sure. |
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rmay635703
Joined: 29 Oct 2005
Posts: 25
Location: Somewhere in Wisconsin
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| Posted: Sat Apr 29, 2006 10:12 pm Post subject: |
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Biodiesel and alcohol have nothing in common besides the fact they can be hydro-carbon based fuels.
Other diff, Biodiesel runs in diesels, alcohol runs in some gassers
My personal experience is that biodiesel is much easier to make (and cheaper) My uncle tried making alcohol once and no it isn't that cheap or easy, biodiesel = easy
Quite frankly I'm not sure why folks fudge around with alcohol so much as the process is not that "easy" Nor can we grow enough corn to sustain much of our fuel consumption. Wheras algae oil grown on winter crop lands, in the ocean and off industrial flues shows more promise of a larger source of fuel than corn could ever be. Though I do burn whole corn to heat my house which as it turns out is much more efficient than turning the corn into alcohol and burning it. We also produce HUGE amounts of methane without even trying, perfect that and sell it as natural gas.
I think methane and algae oil (aka biodiesel stock) made from coal exhaust are some of the most environmentally friendly methods of making alternative fuels. An old article I read from the 70's said americans flush enough energy to power the undeveloped world. The methane is produced whether we go out to bottle it or not, why not convert it into more harmless CO2? (no I dont support methanol at all, only natural gas +30% co2 = methane)
We need to be creative, if crapola, coal, sun and algae can make usefull clean energy I say go for it.
If alcohol fuels (e85) are cheaper for me to run than gas, I will run it as well but I question the environmental aspects of MAKING the alcohol as it does take a fair amount of process energy, in excess of other alternative fuels.
Anyway I prefer diesels over gassers so you can see my bias.
Which brings us to why alcohol has such a following, compatibility with existing gas & spark plug motor designs. Also farmers seem to be only capable of growing a few crops, I would argue there are better fuel crops than corn but whatever floats your boat.
Make a corn burning steam engine and I will be the first to buy it 
Cheers |
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rebelman
Joined: 25 Apr 2006
Posts: 31
Location: North Carolina
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| Posted: Sun Apr 30, 2006 1:52 pm Post subject: |
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| thanks for that information. I see what you are saying about biodiesel being cheaper to make but alcohol is not really that much harder or more expensive to make. They are both good sources for fuels none the less. |
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compu_85
Joined: 27 Apr 2006
Posts: 5
Location: Adrian, MI
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| Posted: Sun Apr 30, 2006 2:10 pm Post subject: |
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| rebelman wrote: | | They are both good sources for fuels none the less. |
Yep! The nice thing about biodiesel is that, unlike with e85, you can run it in any % in any diesel car. You don't have to worry about going back and forth between biodiesel and regular diesel. And you can run the car on 100% biodiesel (I'm gunna be filling up with B99 this week  )
The big problems with biodiesel are:
1. Eats rubber fuel lines (not a problem for vehicles after 1995)
2. REALLY cleans out the fuel system. This means that any crap sitting at the bottom of your fuel tank will get broken up and sent on its way to the fuel filter. FWIW, I started using biodiesel in my car at 150,000 miles, and didn't have any clogging issues at all.
3. Biodiesel has a higher gel point in the winter, IE, it gets thicker at a higher temperature then regular diesel. So you cant use high %'s of it in the winter
4. Underacted and or contaminated biodiesel (or regular diesel) is very bad for the fuel system. A new injection pump and injectors can run you 2 grand... on a 4 Cylinder! (
5. It's easier to find bad quality biodiesel then bad quality regular diesel.
That said, I get my fuel from an excellent source. My car runs fanfrickentastic on it. Yes, there is a little bit of a power hit, and I loose 1-2 MPG (so I get 45 instead of 48, big whoop). It burns cleaner, there's no smoke, and it's actually less expensive right now!
Biodiesel production is also very efficient. To make 3 gallons of biodiesel, you end up using a gallon of regular diesel in the farm equipment. I believe E85 is like 1.8 gallons out for every gallon in? I may be wrong on that.
If only there were more efficient cars that could run it :'(
-Jason
_________________
1999.5 VW Jetta TDI. Running on american made Biodiesel! 212,000 Miles.
1991 VW Jetta GL ECOdiesel. 386,000 miles and running strong! |
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rebelman
Joined: 25 Apr 2006
Posts: 31
Location: North Carolina
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| Posted: Sun Apr 30, 2006 4:10 pm Post subject: |
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If Biodiesel is less expensive to buy they should run it in the farm equipment they use to harvest the crops that they make biofuels with. Biofuels are cleaner burning than petroleum fuels and hopefully one day they can be more fuel efficeint as well.
By the way Compu_85 that is not a bad looking volkswagon.
My uncle should probably look into biodiesel for his dump truck or his big rig. |
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specialgreen
Site Admin
Joined: 10 Jul 2004
Posts: 259
Location: Minneapolis, Minnesota
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| Posted: Sun Apr 30, 2006 4:46 pm Post subject: |
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ADM uses E95 as a "diesel" replacement, so for some "biodiesel", there is a whole lot in common with E-85 ethanol. For most biodiesel, they are completely different.
I know that you can make your own ethanol, but I didn't know you could make your own biodiesel! |
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rebelman
Joined: 25 Apr 2006
Posts: 31
Location: North Carolina
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| Posted: Sun Apr 30, 2006 9:18 pm Post subject: |
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| If the process is similar than it is probably possible. I'm not an expert with diesel to begin with. It may not be any different than ethanol. I am sure that e95 is probably going to become as popular as biodiesel in the future. |
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Revision
Joined: 14 Sep 2005
Posts: 194
Location: Carol Stream, IL
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| Posted: Mon May 01, 2006 12:08 am Post subject: |
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http://oregonstate.edu/dept/ncs/newsarch/2006/Feb06/microreactors.htm
Its getting even easier to produce biodiesel.
Goran Jovanovic, is an Oregon State University professor who has developed a micro-reactor that makes biodiesel instantly from vegie oil and alcohol with no need for waiting or separating the glycerin.
| Quote: | | The microreactor, being developed in association with the Oregon Nanoscience and Microtechnologies Institute (ONAMI), consists of a series of parallel channels, each smaller than a human hair, through which vegetable oil and alcohol are pumped simultaneously. At such a small scale the chemical reaction that converts the oil into biodiesel is almost instant. |
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Pros/Cons of Ethanol vs Biodiesel
Biodiesel works in diesel engines the same way as regular diesel.
There is about a 2% loss in energy if memory serves, but that loss is made up by the fact that biodiesel has a higher lubricity than regular diesel. Biodiesel suffers from geling problems in cold weather. Diesel engines traditionally are very efficient. They work by compressing air and gas until it get hot enough to explode.
Ethanol requires about 30% more volume of fuel than traditional gasoline. So some tuning is required, there is also a small issue with the corrosive properties of Ethanol. There is a lot of hoopla about the energy return for ethanol and if the loss in milage is worth the savings in gasoline or if there is positive energy from using it. Ethanol suffers from cold start problems in cold weather as it requires heat to atomize properly. E85 in a gasoline engine works the same as gasoline by being compressed and ignited by a spark plug.
Biodiesel is more efficient than Ethanol at this time IMHO. But current diesel technology limits the RPM of the motor to about 4000-5000 rpm. Ethanol is effectively high octane gasoline that runs cooler with a longer exhaust pulse so it can run high rpm's as designed into the motor. There are experimental technologies in the works for diesel engines in an attempt to increase the rpm limit by changing the exhaust pulse and detionation sequence. |
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compu_85
Joined: 27 Apr 2006
Posts: 5
Location: Adrian, MI
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| Posted: Mon May 01, 2006 10:43 am Post subject: |
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Just so ya know, the 5000 rpm redline isn't a limit on my car. In 5th gear, 60 MPH is 2000 RPM. 2000 RPM is also where the torque peak is 70-90 times are also very good  Fastest I've gon was 105, and it had more pull. And that was before I upgraded the fuel injectors!!!
-Jason
_________________
1999.5 VW Jetta TDI. Running on american made Biodiesel! 212,000 Miles.
1991 VW Jetta GL ECOdiesel. 386,000 miles and running strong! |
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rebelman
Joined: 25 Apr 2006
Posts: 31
Location: North Carolina
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| Posted: Mon May 01, 2006 3:06 pm Post subject: |
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| The Biodiesel production process sounds easy enough to get more than enough biodiesel to run many larger trucks and equipment on. Hopefully one day we will only use biofuels. Many of the other countries around the world should also consider biofuels. |
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Sinner
Joined: 04 Aug 2005
Posts: 33
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archangel2003
Joined: 17 Jan 2006
Posts: 7
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| Posted: Sun Jun 25, 2006 6:48 pm Post subject: |
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[quote="Revision"]
Pros/Cons of Ethanol vs Biodiesel
Biodiesel is more efficient than Ethanol at this time IMHO. But current diesel technology limits the RPM of the motor to about 4000-5000 rpm.
[/quote]
Where do you get the idea that Diesel engines can turn over that fast?!
The Diesel is ignighted by heating the incoming air by compressing it with something like 18:1 to 22:1 compression ratios and to do that the pistons have to be stout (KAK thick and strong) and those heavy pistons need stout rods (KAK thick and strong) to hold them, and then onto the crank which as to be stout, but you can understand where this is leading to, right?
Well in Diesel engine design there is what is called the "rod stretch factor" which tells you that if it turns over too fast "RPM's" the piston will stretch the rod enough that the piston will hit the head!
Not a good thing with those heavy pistons!
So most BIG truck Diesels only turn oner about 2000 to about 2500 RPM's, and smaller auto Diesels are limited to about 2800 to 3200 RPM's at the most, so there is no way they will be turning over 5000 rpm's.
[quote="Revision"]
Ethanol is effectively high octane gasoline that runs cooler with a longer exhaust pulse so it can run high rpm's as designed into the motor. There are experimental technologies in the works for diesel engines in an attempt to increase the rpm limit by changing the exhaust pulse and detionation sequence.[/quote]
Well, you are only partly right here, but a longer "exhaust pulse" would cause you to need a slower RPM as it would take longer to push the piston!
It is a more gentile ignition and with a slightly slower burn rate would cause a need to advance the timing a little, but it's not a huge differance.
The higher octane level will allow the engine to run a much higher compression ratio so you can get more energy out of the engine under a steady cruising speed and if the compression is high enough, you should be able to get similar mileage out of that Ethanol as you did out of the lower compression engine got out of Gasoline.
Right now I'm building an aluminum Buick 215 V8 with high compression pistons so as to run only Ethanol.
The RPM's have little to do with it in either case as RPM's are a factor of piston speed, piston weight and rod strength, any fuel no matter what it is will not let you run any engine outside of it's RPM design.
Think of the diference like a Ferrari with tiny little 250 CC pistons screaming down the freeway and a Diesel truck engine with huge 10 pound slugs of Aluminum for pistons thumping down the freeway! |
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hotrod
Joined: 19 Apr 2005
Posts: 872
Location: Colorado
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archangel2003
Joined: 17 Jan 2006
Posts: 7
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| Posted: Sun Jun 25, 2006 11:37 pm Post subject: |
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[quote="hotrod"] | Quote: | smaller auto Diesels are limited to about 2800 to 3200 RPM's at the most, so there is no way they will be turning over 5000 rpm's.
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The Audi R-10 TDI that just won the 24 hours of Le Mans, has a redline of 5500 rpm and shifted at about 5000 rpm.
http://www.audi.com/audi/com/en1/experience/motorsport/Audi_R10_TDI/v12_tdi_engine.html
Larry[/quote]
And the gas engines in that same race were turning over, what, 12,000 RPM's or more?
Compare that to street gas engines turning 6,000 RPM's.
OK, if you want to fab up Titanium pistons, rods and crank shaft it can be done.
But what I'm talking about are real on the street vehicles, not multi-million dollar ($1,000,000+) budgeted racing machines tuned to insane levels that get rebuilt after every race (that is assuming they survive in the first place).
And what displacement was that V12, 2 or 3 liters?
If so those would be some small pistons for a diesel and likely to be more RPM friendly.
Fererri had a thing for naming their cars after the displacement of one cylinder, like the 250 California Special, which was 250cc's for each cylinder so it was a 3 liter V12.
Compare a Honda single cylinder 600 cc motorcycle engine @ 6000 RPM's with a Honda 4 cylinder 600 cc motorcycle engine @14,000 RPM's.
In the real world, diesels run much lower RPM's than Gasoline engines because their pistons are much larger and the stroke is as well.
And even larger Gas engines run lower RPM's than smaller ones for the same reason, piston weight and stroke length. |
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Revision
Joined: 14 Sep 2005
Posts: 194
Location: Carol Stream, IL
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| Posted: Tue Jun 27, 2006 6:34 am Post subject: |
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| Quote: |
Where do you get the idea that Diesel engines can turn over that fast?!
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Heh, lets stick to cars. I watched my friend who is a diesel mechanic tear appart one of those "Big" trucks. That engine block is the size of my tea table and the piston faces look like dinner plates. I can't imagine those things turning over very fast. My only real experience driving a diesel is a VW Golf TDI. Redline is 5000 rpm. Power seems to drop off fast after 4000 rpm. Peak torque seems to be around 2500 to 3000 rpm. Still a blast to drive because of gearing. Of course, its got a tiny inline-4 engine and a tiny turbo.
I'm kind of a diesel noob, so if I get any of the concepts wrong let me know.
I was refering to some new technology which is trying to improve the way the diesel makes power at higher rpm and possibly allow the diesel engine to have a higher peak rpm and yeah maybe even a higher redline. One of the downsides to current diesel technology is that there is no way to control timing. (Lets assume a NA motor) Combustion occurs when the pistons have compressed the air/fuel charge to the point where the compression has heated the air/fuel charge to the point of spontaneous detonation. This means that ignition occurs at TDC (timing adv = 0) at every point of the rpm curve. Now the rate of combustion is pretty much a constant, no matter what point of the rpm curve. This means that power drops off at higher rpm because there is less time for the combustion burn to complete and deliver the energy to the piston before it is ejected out the exhaust port. By adding the advantage of timing and igniting the charge before TDC, we are allowing the combustion of the air/fuel charge a chance to get going so that more energy can be delivered before the piston reaches BDC. Diesel engines do not currently have the advantage of timing advance. But some smart boys and girls are playing with some new cylinder head designs and a way of keeping a variable mix of hot exhaust gases and fuel to create a preignition state to start the ignition of diesel fuel earlier in the compression stroke. A diesel motor with variable timing ability. Can you imagine? |
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