Using Biodiesel In Diesel Engines
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From: Why-homing
Using Biodiesel In Diesel Engines
Using Biodiesel In Diesel Engines
IntroductionTo use Biodiesel in a diesel engine, simply pour it in the fuel tank and use the engine as normal.
Yeah, it's THAT simple. No modifications, no second fuel tanks, no heat exchangers, just pour it in and go.
Biodiesel can also be blended with petrodiesel in any ratio. Pure Biodiesel is labelled B100 (the number representing the percentage of Biodiesel), when it's blended, it's labelled with the percent of Biodiesel after the B. For example, B90 is 90% Biodiesel, 10% some other fuel (typically petrodiesel).
Fuel Lines
On diesel engines made before 1993, the fuel lines were typically made from rubber (usually nitrile rubber). Biodiesel's solvent properties tend to break these down over time. It is recommended that when using Biodiesel in pre-1993 diesel engines that the fuel lines be monitored for breakdown and possibly replaced, especially when using blends of 30% Biodiesel or greater. Viton fuel lines or other synthetic (non-rubber) fuel lines can be used as replacements. Diesel engine vehicles made after 1993 usually are 100% compatible with Biodiesel. If in doubt, check with the manufacturer.
Fuel Filters
When first using Biodiesel it is recommended to replace the fuel filter on your engine. Because of the solvent properties in Biodiesel, it may cause the release of accumulated deposits inside the fuel tank and fuel lines from years of petrodiesel use. These deposits can flow down the fuel line and may plug the fuel filter. Luckily, most of the time the filter's don't plug all at once, but slowly, causing slight hesitations in engine acceleration, missing (cylinder's not all firing), or other sluggish behavior.
A good rule of thumb to follow is to replace the fuel filter before beginning to use biodiesel and then replace it again after a few thousand miles of Biodiesel use, especially if using percentages of Biodiesel of 30% or greater. Think of it this way, Biodiesel is not only good for the environment, but it actually acts as a fuel system cleaner, cleaning the injectors, fuel pump, fuel tank, and fuel lines. In fact, it's solvent properties are so widely known that many fuel additive manufacturer's use it as an ingredient in several of their additive products.
Emmissions
One of the benefits of using Biodiesel in a diesel engine is that it can help to reduce the amount of tailpipe emmissions. In fact, studies have shown that there is a substantial reduction in the amount of carbon monoxide, unburned hydrocarbons, carbon dioxide and particulate matter over emmissions that Petrodiesel emits. It also has a nice effect of changing the smell of the exhast. Most people say that it tends to smell like french fries. Kind of a nice swap over the petrodiesel smell--that is unless you like that smell.
Biodiesel emmision benefits begin with the use of a relatively low blend of biodiesel. Studies have shown that a noticable difference has been measured with even a 20% mix of Biodiesel in Petrodiesel (B20). Continued use of Biodiesel overtime will also help the engine to run better due to the fuel system becoming cleaner.
Engine Warranties
Several diesel engine manufacturer's will warrant the use of Biodiesel that is commercially made up to B20 and some even beyond that. Check with the manufacturer for specific details.
Engine Performance
Biodiesel has been shown to produce similar performance when compared to Petrodiesel. One noticable difference, fairly quickly after using it, is that the noise emmision of the engine goes down. Sometimes drastically, depending on the engine it's used in. This is due to Biodiesel having a higher lubricity than Petrodiesel. Think of it like this. It's "slipperier" than Petrodiesel. There's lots of chemical stuff that can explain it, but for the average user, the noticable difference is a quieter engine, easier starts, and less vibration. The effect increases as the percentage of Biodiesel used increases per gallon of fuel.
There has been documented evidence that shows there to be a slight decrease in power, somewhere between 5% to 10%. This is due to several factors, but essentially, it has to do with the BTU equivalent of Biodiesel when compared to Petrodiesel. Most users don't notice this small of a decrease in power while gaining all of the benefits. Individual results may vary.
Cold Weather Use
Here in Utah we run into a problem. It get's nice and cold in the winter time. Diesel fuel in Utah is winterized each winter to prevent one big problem; gelling fuel. Biodiesel has the same issue, it has the potential to gel. In fact, Biodiesel has a higher gel point than Diesel fuel. If you plan on using Biodiesel in the winter in Utah, plan on "winterizing" it. To do so, most people just blend with petrodiesel at about a 50% mix (B50). Using a 50% mix should allow you to run your diesel in the winter without any problems. Visit this link for some great advice on how to winterize your biodiesel.
http://www.utahbiodieselsupply.com/usingbiodiesel.php
IntroductionTo use Biodiesel in a diesel engine, simply pour it in the fuel tank and use the engine as normal.
Yeah, it's THAT simple. No modifications, no second fuel tanks, no heat exchangers, just pour it in and go.
Biodiesel can also be blended with petrodiesel in any ratio. Pure Biodiesel is labelled B100 (the number representing the percentage of Biodiesel), when it's blended, it's labelled with the percent of Biodiesel after the B. For example, B90 is 90% Biodiesel, 10% some other fuel (typically petrodiesel).
Fuel Lines
On diesel engines made before 1993, the fuel lines were typically made from rubber (usually nitrile rubber). Biodiesel's solvent properties tend to break these down over time. It is recommended that when using Biodiesel in pre-1993 diesel engines that the fuel lines be monitored for breakdown and possibly replaced, especially when using blends of 30% Biodiesel or greater. Viton fuel lines or other synthetic (non-rubber) fuel lines can be used as replacements. Diesel engine vehicles made after 1993 usually are 100% compatible with Biodiesel. If in doubt, check with the manufacturer.
Fuel Filters
When first using Biodiesel it is recommended to replace the fuel filter on your engine. Because of the solvent properties in Biodiesel, it may cause the release of accumulated deposits inside the fuel tank and fuel lines from years of petrodiesel use. These deposits can flow down the fuel line and may plug the fuel filter. Luckily, most of the time the filter's don't plug all at once, but slowly, causing slight hesitations in engine acceleration, missing (cylinder's not all firing), or other sluggish behavior.
A good rule of thumb to follow is to replace the fuel filter before beginning to use biodiesel and then replace it again after a few thousand miles of Biodiesel use, especially if using percentages of Biodiesel of 30% or greater. Think of it this way, Biodiesel is not only good for the environment, but it actually acts as a fuel system cleaner, cleaning the injectors, fuel pump, fuel tank, and fuel lines. In fact, it's solvent properties are so widely known that many fuel additive manufacturer's use it as an ingredient in several of their additive products.
Emmissions
One of the benefits of using Biodiesel in a diesel engine is that it can help to reduce the amount of tailpipe emmissions. In fact, studies have shown that there is a substantial reduction in the amount of carbon monoxide, unburned hydrocarbons, carbon dioxide and particulate matter over emmissions that Petrodiesel emits. It also has a nice effect of changing the smell of the exhast. Most people say that it tends to smell like french fries. Kind of a nice swap over the petrodiesel smell--that is unless you like that smell.
Biodiesel emmision benefits begin with the use of a relatively low blend of biodiesel. Studies have shown that a noticable difference has been measured with even a 20% mix of Biodiesel in Petrodiesel (B20). Continued use of Biodiesel overtime will also help the engine to run better due to the fuel system becoming cleaner.
Engine Warranties
Several diesel engine manufacturer's will warrant the use of Biodiesel that is commercially made up to B20 and some even beyond that. Check with the manufacturer for specific details.
Engine Performance
Biodiesel has been shown to produce similar performance when compared to Petrodiesel. One noticable difference, fairly quickly after using it, is that the noise emmision of the engine goes down. Sometimes drastically, depending on the engine it's used in. This is due to Biodiesel having a higher lubricity than Petrodiesel. Think of it like this. It's "slipperier" than Petrodiesel. There's lots of chemical stuff that can explain it, but for the average user, the noticable difference is a quieter engine, easier starts, and less vibration. The effect increases as the percentage of Biodiesel used increases per gallon of fuel.
There has been documented evidence that shows there to be a slight decrease in power, somewhere between 5% to 10%. This is due to several factors, but essentially, it has to do with the BTU equivalent of Biodiesel when compared to Petrodiesel. Most users don't notice this small of a decrease in power while gaining all of the benefits. Individual results may vary.
Cold Weather Use
Here in Utah we run into a problem. It get's nice and cold in the winter time. Diesel fuel in Utah is winterized each winter to prevent one big problem; gelling fuel. Biodiesel has the same issue, it has the potential to gel. In fact, Biodiesel has a higher gel point than Diesel fuel. If you plan on using Biodiesel in the winter in Utah, plan on "winterizing" it. To do so, most people just blend with petrodiesel at about a 50% mix (B50). Using a 50% mix should allow you to run your diesel in the winter without any problems. Visit this link for some great advice on how to winterize your biodiesel.
http://www.utahbiodieselsupply.com/usingbiodiesel.php
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From: Why-homing
By Troy
I see we have a few questions about winter fuel treatment. Let me start by saying, I'm not an expert at this, just an educated amateur. So, your mileage may vary.
Here's a copy, with a few minor revisions, of my previous post about how I do winter fuel.
When you speak of winter treatment of biodiesel, you have entered the dark arts.
I say that because your homebrew can be subtly or dramatically different than mine, your vehicle can be more or less tolerant of some wax precipitate, and your weather can certainly be different than mine. The following discussion assumes you are making top quality, well converted, properly washed, dried and filtered biodiesel. If you are cutting corners on any of that, you can get stranded and freeze your genitals off. You’ve been warned.
Despite all that, here are some general guidelines:
A. Your starting oil matters. Unhydrogenated canola is generally considered to make the best winter biodiesel. Soy is pretty good. Animal fats, coconut oil and palm oil are terrible winter stocks. The resultant biodiesel gels in the temp range of 40-70F. Partially hydrogenated oils (shortening, often a semi-liquid) can give anything from good to terrible winter performance. Fully hydrogenated veggie oils (even canola) make lousy winter fuel. These oils are solid at room temperature.
B. Blending with winterized petro diesel works, kerosene works even better. The colder it gets, the more diesel or kero you need. I'll post some data from Duffscience later that shows how much petro diesel or kerosene it takes to attain a certain gel temp. There’s also a link with a nifty calculator to estimate how much K-1 you need.
C. Additives. None of the diesel additives for winter work as well in biodiesel as they do in petro diesel. Some additives work reasonably well if you double or triple the percentage added. This can get quite expensive. There is a lot of research going on right now to find the holy grail additive that will relieve us of the need to mix petro. So far as I know (September, 2007) it doesn’t exist yet.
Whatever scheme you decide on, be certain to do your own freezer testing to find out how your blend works. You should measure cloud temp (the temp at which the biodiesel starts to get wispy cloudy stuff (wax crystals coming out of solution)) and gel temp, the temp at which the biodiesel no longer behaves as a liquid when you tilt your container on its side. You can drive, for a time, with cloudy fuel. But eventually the wax crystals will plug your fuel filter and you will be walking. Once the fuel gels, you are totally beat. Cloud temp is usually a few to several degrees above gel temp.
Oh yeah, and if your fuel clouds at 30F overnight, you might discover that it clouds at 37 F if you chill it/check it for a few days. Same with gel temps. An “overnight” reading of 17F is no guarantee that it won’t gel at 8 or 10 degrees (F) higher if you chill it for a week. Did I mention that this is a black art?
Here's what I do, which is a combination of blending with K-1, additives and cold processing to take the high temp waxes out.
1: Mix your washed/dried Biodiesel with some percentage of kerosene. I typically add enough kerosene to make true B-66. Do the mixing warm if at all possible and mix it well. By warm, I mean more than 60F.
2. Add 3x the recommended amount of Power Service DFS (Diesel Fuel Supplement) cetane improver. This comes in a white bottle and is available at most Wal-Marts and just about any truck stop. Mix well. Some sources say this step must be done at warm temperatures (like around 60F) to be maximally effective.
3. Cold processing. That's where you "refrigerate" your mix for a few days (which in my case usually means leaving it outside for a few days) and then siphoning out the liquid portion the next day and leaving the crystallized sludge portion for summer use. If I don’t get 3 days of good cold weather, I throw a couple of cubies in the freezer for 24 hours. A longer chill period is much more effective than a short one. It's amazing how much more junk precipitates after a full day in the freezer compared with just overnight. Then I let it warm up a bit to clarify the liquid fuel and really settle the waxes. This improves yields a little. Make sure you do this so you can go right to the siphoning step without disturbing the jug. Siphon the clear stuff out and you’re good to go. The finished product of course is no longer B-66, but something less than that, depending on 27 different things.
I use a siphon with a “J” shaped bend on the end that I made out of 2 copper 90’s. It makes it much easier to siphon from the top down and not disturb the waxy sludge on the bottom. The colder you chill the mix, the better the anti-gel performance in cold temps, and the lower your yield. Interestingly, the precipitated sludge has more BTU’s per liter, so you may notice slightly reduced performance on the winter blend. The “sludge” makes great summer fuel.
That's it for the fuel. Of course, there are other factors as well:
1. My car always sits in a garage overnight, along with my wife's car. This helps retain heat. Perhaps your car is exposed to the full fury of winter temps overnight…
2. I added a 120V coolant heater to my VW and use it religiously at or below freezing. So my engine does not start off stone cold in the morning. This increases under-hood temperatures and also makes my heater work right away, which is a nice bonus.
3. TDI engines like mine use a continuous fuel loop, so excess fuel (which is hot) gets returned to the tank. If it's cold out, it routes that hot fuel through the fuel filter canister. If your diesel doesn't do that, you could have a problem with wax crystals plugging the filter.
4. I have a Neoteric brand 12V fuel line heater activated by a rocker switch on the dash. This is in the fuel line just prior to the fuel filter.
5. Never fill the tank right full, so if you have a sudden -20F cold snap, you could dump a bunch of kerosene or winterized diesel in there, along with some more anti-gel additive. You’d at least stand a chance then.
6. I keep a quart jar of winter blend fuel outside on the way to the garage. That gives me a visual check of what's going on in the tank.
7. In some previous model years, they had a problematic fuel pickup in the tank that would plug with even trivial amounts of crystallization in the fuel. The newer design eliminates that problem. Who knows what your pickup looks like.
I am thinking about setting up a coolant loop to heat the fuel tank, like the SVO folks do.
(I have since discarded this notion, since my formula has been 100% successful the last two winters.)
Please note that you should mix your blend for worst case scenario temperatures plus a fudge factor of several degrees. You should not look at the forecast for tomorrow and mix your blend for that exact temperature. Or maybe you like living on the edge???
Here’s the charts and links I promised…
Try this newer link (good as of 2/1/07):
http://www.duffscience.com/bd_calculators.htm
The following numbers are all based on mixes with biodiesel made from new soy oil. YMMV
% BioDiesel %Wint.D Gel temp in F
10 90 2F
20 80 4
30 70 6
40 60 8
50 50 10
60 40 13
70 30 17
80 20 21
90 10 25
100 0 32
% BioDiesel %Kerosene Gel temp in F
10 90 -28
20 80 -23
30 70 -17
40 60 -11
50 50 -5
60 40 2
70 30 9
80 20 16
90 10 24
100 0 32
I see we have a few questions about winter fuel treatment. Let me start by saying, I'm not an expert at this, just an educated amateur. So, your mileage may vary.
Here's a copy, with a few minor revisions, of my previous post about how I do winter fuel.
When you speak of winter treatment of biodiesel, you have entered the dark arts.
I say that because your homebrew can be subtly or dramatically different than mine, your vehicle can be more or less tolerant of some wax precipitate, and your weather can certainly be different than mine. The following discussion assumes you are making top quality, well converted, properly washed, dried and filtered biodiesel. If you are cutting corners on any of that, you can get stranded and freeze your genitals off. You’ve been warned.
Despite all that, here are some general guidelines:
A. Your starting oil matters. Unhydrogenated canola is generally considered to make the best winter biodiesel. Soy is pretty good. Animal fats, coconut oil and palm oil are terrible winter stocks. The resultant biodiesel gels in the temp range of 40-70F. Partially hydrogenated oils (shortening, often a semi-liquid) can give anything from good to terrible winter performance. Fully hydrogenated veggie oils (even canola) make lousy winter fuel. These oils are solid at room temperature.
B. Blending with winterized petro diesel works, kerosene works even better. The colder it gets, the more diesel or kero you need. I'll post some data from Duffscience later that shows how much petro diesel or kerosene it takes to attain a certain gel temp. There’s also a link with a nifty calculator to estimate how much K-1 you need.
C. Additives. None of the diesel additives for winter work as well in biodiesel as they do in petro diesel. Some additives work reasonably well if you double or triple the percentage added. This can get quite expensive. There is a lot of research going on right now to find the holy grail additive that will relieve us of the need to mix petro. So far as I know (September, 2007) it doesn’t exist yet.
Whatever scheme you decide on, be certain to do your own freezer testing to find out how your blend works. You should measure cloud temp (the temp at which the biodiesel starts to get wispy cloudy stuff (wax crystals coming out of solution)) and gel temp, the temp at which the biodiesel no longer behaves as a liquid when you tilt your container on its side. You can drive, for a time, with cloudy fuel. But eventually the wax crystals will plug your fuel filter and you will be walking. Once the fuel gels, you are totally beat. Cloud temp is usually a few to several degrees above gel temp.
Oh yeah, and if your fuel clouds at 30F overnight, you might discover that it clouds at 37 F if you chill it/check it for a few days. Same with gel temps. An “overnight” reading of 17F is no guarantee that it won’t gel at 8 or 10 degrees (F) higher if you chill it for a week. Did I mention that this is a black art?
Here's what I do, which is a combination of blending with K-1, additives and cold processing to take the high temp waxes out.
1: Mix your washed/dried Biodiesel with some percentage of kerosene. I typically add enough kerosene to make true B-66. Do the mixing warm if at all possible and mix it well. By warm, I mean more than 60F.
2. Add 3x the recommended amount of Power Service DFS (Diesel Fuel Supplement) cetane improver. This comes in a white bottle and is available at most Wal-Marts and just about any truck stop. Mix well. Some sources say this step must be done at warm temperatures (like around 60F) to be maximally effective.
3. Cold processing. That's where you "refrigerate" your mix for a few days (which in my case usually means leaving it outside for a few days) and then siphoning out the liquid portion the next day and leaving the crystallized sludge portion for summer use. If I don’t get 3 days of good cold weather, I throw a couple of cubies in the freezer for 24 hours. A longer chill period is much more effective than a short one. It's amazing how much more junk precipitates after a full day in the freezer compared with just overnight. Then I let it warm up a bit to clarify the liquid fuel and really settle the waxes. This improves yields a little. Make sure you do this so you can go right to the siphoning step without disturbing the jug. Siphon the clear stuff out and you’re good to go. The finished product of course is no longer B-66, but something less than that, depending on 27 different things.
I use a siphon with a “J” shaped bend on the end that I made out of 2 copper 90’s. It makes it much easier to siphon from the top down and not disturb the waxy sludge on the bottom. The colder you chill the mix, the better the anti-gel performance in cold temps, and the lower your yield. Interestingly, the precipitated sludge has more BTU’s per liter, so you may notice slightly reduced performance on the winter blend. The “sludge” makes great summer fuel.
That's it for the fuel. Of course, there are other factors as well:
1. My car always sits in a garage overnight, along with my wife's car. This helps retain heat. Perhaps your car is exposed to the full fury of winter temps overnight…
2. I added a 120V coolant heater to my VW and use it religiously at or below freezing. So my engine does not start off stone cold in the morning. This increases under-hood temperatures and also makes my heater work right away, which is a nice bonus.
3. TDI engines like mine use a continuous fuel loop, so excess fuel (which is hot) gets returned to the tank. If it's cold out, it routes that hot fuel through the fuel filter canister. If your diesel doesn't do that, you could have a problem with wax crystals plugging the filter.
4. I have a Neoteric brand 12V fuel line heater activated by a rocker switch on the dash. This is in the fuel line just prior to the fuel filter.
5. Never fill the tank right full, so if you have a sudden -20F cold snap, you could dump a bunch of kerosene or winterized diesel in there, along with some more anti-gel additive. You’d at least stand a chance then.
6. I keep a quart jar of winter blend fuel outside on the way to the garage. That gives me a visual check of what's going on in the tank.
7. In some previous model years, they had a problematic fuel pickup in the tank that would plug with even trivial amounts of crystallization in the fuel. The newer design eliminates that problem. Who knows what your pickup looks like.
I am thinking about setting up a coolant loop to heat the fuel tank, like the SVO folks do.
(I have since discarded this notion, since my formula has been 100% successful the last two winters.)
Please note that you should mix your blend for worst case scenario temperatures plus a fudge factor of several degrees. You should not look at the forecast for tomorrow and mix your blend for that exact temperature. Or maybe you like living on the edge???
Here’s the charts and links I promised…
Try this newer link (good as of 2/1/07):
http://www.duffscience.com/bd_calculators.htm
The following numbers are all based on mixes with biodiesel made from new soy oil. YMMV
% BioDiesel %Wint.D Gel temp in F
10 90 2F
20 80 4
30 70 6
40 60 8
50 50 10
60 40 13
70 30 17
80 20 21
90 10 25
100 0 32
% BioDiesel %Kerosene Gel temp in F
10 90 -28
20 80 -23
30 70 -17
40 60 -11
50 50 -5
60 40 2
70 30 9
80 20 16
90 10 24
100 0 32
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