dieselcruiserhead
16 Years on ExPo. Whoa!!
I couldn't really think of a place to post this and I'm writing up the directions for a fellow member so I thought I would just post them here and make them 'interactive' so basically if I forget something or people have questions you can post them up here...
-- Biodiesel brewing is a chemical process where you are basically after a section of a molecule called a triglyceride. You then introduce an alcohol to the triglyceride and this creates the biodiesel molecule. Vegetable oil is basically the most easily available source of the molecule but just as biodiesel can be brewed from 20 gallion things (animal lard, etc) the most abundant and easy to control source is vegetable oil and the triglyceride is basically the fat portion of that molecule. We use "lye" to break apart the molecule, and the easiest to introduce/use alcohol is methanol (which is basically race car fuel) but biodiesel can also be brewed from several different types of oil.
In our case the reaction is simple:
1) Add oil to your processor and determine how much oil you have in liters. 1 gallon of oil x 3.84 = how many liters you have.
2) heat the oil to 120-140 degrees F. At 140 F methanol boils so definitely keep it below this tempurature. Even at 120-140 you will have significant boil-off of your methanol so keep this in mind... If you have a sealed processor one thing that comes to mind once you've added your methanol/lye methoxide mix is to close the vent to keep methanol from boiling off but this is a 'do as you see fit' recommendation.
3) pull a very small portion of the oil out once it's heated and mixed, to do a titration. This can be done as step 1 and it doesn't need to be heated (lots of people titrate before they even collect the oil to see if its of any value). Titration basically measures how 'spent' or used the oil is, and this determines how much lye to use. Here are directions of titration:
Always wear safety equipment. Don't breath or touch this stuff. Biodiesel is nontoxic after you've washed the methanol and glycerine/lye out, not before.
For the reference solution:
1. add 1000ml distilled water
2. add 1 gram NaOH or KOH
For the titration:
1. add 10 ml isopropyl alcohol
2. add 4 drops phenolphthalein indicator solution
3. “blank” the jar with a few drops -OH reference solution – swirl and add until the purple stays
4. add 1 ml oil (be exact)
5. measure 10 ml -OH reference solution – swirl and add until the purple stays.
6. note how many ml -OH reference solution you used.
This will be the grams (Na or K)-OH added on top of the catalyst amount to strip the free fatty acids. The base amount of KOH (potassium hydroxide) is 6.5 grams per liter. So if your oil titrates at 5 grams per liter, then you add 11.5 grams per liter of lye for each liter of vegetable oil you have.
I forget what the base about of NaOH (basic "red devil lye") is but brewing with KOH lye is much better. A little more expensive but your biproduct glycerin is always liquid, it desolves easier into your methanol, and generally brews better. KOH is about $55 a 50 lb bag of KOH flake from a good inexpensive industrial chemical supplier found in any large city.
4) In a seperate container collect 22% of whatever your total oil volume is methanol. So if you have 100 liters of oil collect 22 liters of methanol in a seperate container.
5) Very carefully, in an open vented area with respirator and goggles on, add the lye amount you calculated in step 3 into the methanol. For example if you have 100 liters of oil and it titrated at 5 grams per liter and you are using KOH lye (which has a base level of 6.5 grams per liter) then you add 11.5 grams per liter of oil. So for those 100 liters of oil add 1150 grams of KOH into your methanol.
It will get warm and fizzle. If you use KOH-type lye it will fizzle and should dissolve into the methanol easily with minimal rocking of the container, no stirring required. If using NaOH lye you will need to mix it thoroughly which is also more dangerous to you.
Once dissolved this forms a new chemical called methoxide.
6) Very slowly and/or thoroughly add your methoxide to your oil once the oil is at temperature. Again with respirator on in any open-vessel type processor where you can easily breathe the fumes as the heated methoxide and methanol fumes are flammable and dangerous to your health. If you add your methoxide too quickly to can pool and stay at the top of the vessel particularly in a sealed vessel like an appleseed-type processor.
Once added mix the mixture throughly for at least 1 hour (two recommended, more than 2 hours not needed) using some sort of electrical mixer. I have seen all types of mixers including electric trolling boat motors, electric inline pumps that pull from the bottom and add to the top.
One thing to consider is to also turn off your heat at this step though this is not necessary now either.
7) Internal notes to self for this step: The reaction is now happening. At this point you can pull a small sample out of the processor into something like a glass mason jar and watch the glycerin fall out of the mixture, yielding biodiesel on top and by-product glycerin on the bottom. The reaction happens easily and quickly for the first 90% of the reaction but the last 10% is stubborn and any unreacted oil will clog filters, possibly damage engines, etc, so you want to make sure the reaction is complete and thorough. We actually only need 16% methanol (or that is all the reaction consumes) and a lesser amount of KOH/Lye, and less than an hour to stir, but that last 10% is stubborn and needs these factors to thoroughly complete the reaction, though I'm told the wash phase will also pull out unreacted vegetable oil out of the biodiesel product.
8) Turn off mixer after those 2 hours, and let it sit for at least 8 hours preferably 24 hours or a full day as more and more glycerin will continue to fall to the bottom of the processor. It is normal ot have a little unreacted methanol sitting at the very top of the biodiesel (appearing to look like a thin layer of water almost) and that is OK. Also consider turning off your heat as well unless it is quite cold and your product will freeze of gel (below 40 F).
9) Drain off the glycerin layer our of your processor. If you The technique for this varies largely by type of processor you have but what is important is when the switch occurs it will be quickly, and you will see a quick transition in your drain tube from molassis-like glycerin to quick-moving fairly clear biodiesel. The color of the bioidesel varies considerably from dark amber (fairly 'spent' oil) to light colored from oil from Asian restaurants that is fairly new/unused. If you processor has solid glycerin from using NaOH simply turn on your heat again and it will return to liquid form.
10) Pull the biodiesel out of your processor and put into wash tank unless your processor uses your processor also as a wash tank. At this point the biodiesel can be run but can do long term damage to your engine because of invisible contaminents and residual methanol. Some of the contaminents can be filtered out but not all and it is highly recommended to bubble wash your fuel to have it meet ASTM certified biodiesel spec (which is fairly easy to reach once you have bubble washed).
Add about 1:1 ratio water to your biodiesel so 100 liters of oil, add 100l of water to it. The biodiesel is sensitive to violent introductions of water so try to add it "softly" so slow water induction rate or even mist it in. The water is molecularly heavier so it will go to the bottom of the tank and sit there and will already begin to start having a lightly milky appearance to it.
From here, use a bubble washer, which is fish tank pump with some sort of porous gizmo at the end that yields nice small bubbles and turn this on for at least 24 hours. The more small bubbles you have and basically the bubbles bring water to the surface, the water falls, and something about the ionization of the water pulls any contaminants and left over methanol and unreacted oil out of the biodiesel into the water until the water gets saturated. If you start getting emulsification aka "mayonaise" at this step no matter what it means you didn't mix your methoxide and oil throughly in the reaction process. If you introduce the water in too quickly/violently it can also lead to emulsification.
After the water is saturated (24 hours again) discharge of the water (drain is OK) and add another 50-100 litres. This water will have difficulty getting saturated and should stay a light milky color versus the thick milky color of the first batch after 24 hours of washing. Once you turn off (you do not have to discharge this water if you don't want to, you can re-use it for the next batch if your setup allows for this) you must add heat to the biodiesel around 80-90F recommended (if this is your room temp then no heat required) and let it sit another 24 hours to "dry." Once dry, you biodiesel is ready to be run!
I'm going to bed now, photos to come tomorrow..
EDIT never did snap photos before I shipped it off. Sorry about this, perhaps someone can take or post pics?
-- Biodiesel brewing is a chemical process where you are basically after a section of a molecule called a triglyceride. You then introduce an alcohol to the triglyceride and this creates the biodiesel molecule. Vegetable oil is basically the most easily available source of the molecule but just as biodiesel can be brewed from 20 gallion things (animal lard, etc) the most abundant and easy to control source is vegetable oil and the triglyceride is basically the fat portion of that molecule. We use "lye" to break apart the molecule, and the easiest to introduce/use alcohol is methanol (which is basically race car fuel) but biodiesel can also be brewed from several different types of oil.
In our case the reaction is simple:
1) Add oil to your processor and determine how much oil you have in liters. 1 gallon of oil x 3.84 = how many liters you have.
2) heat the oil to 120-140 degrees F. At 140 F methanol boils so definitely keep it below this tempurature. Even at 120-140 you will have significant boil-off of your methanol so keep this in mind... If you have a sealed processor one thing that comes to mind once you've added your methanol/lye methoxide mix is to close the vent to keep methanol from boiling off but this is a 'do as you see fit' recommendation.
3) pull a very small portion of the oil out once it's heated and mixed, to do a titration. This can be done as step 1 and it doesn't need to be heated (lots of people titrate before they even collect the oil to see if its of any value). Titration basically measures how 'spent' or used the oil is, and this determines how much lye to use. Here are directions of titration:
Always wear safety equipment. Don't breath or touch this stuff. Biodiesel is nontoxic after you've washed the methanol and glycerine/lye out, not before.
For the reference solution:
1. add 1000ml distilled water
2. add 1 gram NaOH or KOH
For the titration:
1. add 10 ml isopropyl alcohol
2. add 4 drops phenolphthalein indicator solution
3. “blank” the jar with a few drops -OH reference solution – swirl and add until the purple stays
4. add 1 ml oil (be exact)
5. measure 10 ml -OH reference solution – swirl and add until the purple stays.
6. note how many ml -OH reference solution you used.
This will be the grams (Na or K)-OH added on top of the catalyst amount to strip the free fatty acids. The base amount of KOH (potassium hydroxide) is 6.5 grams per liter. So if your oil titrates at 5 grams per liter, then you add 11.5 grams per liter of lye for each liter of vegetable oil you have.
I forget what the base about of NaOH (basic "red devil lye") is but brewing with KOH lye is much better. A little more expensive but your biproduct glycerin is always liquid, it desolves easier into your methanol, and generally brews better. KOH is about $55 a 50 lb bag of KOH flake from a good inexpensive industrial chemical supplier found in any large city.
4) In a seperate container collect 22% of whatever your total oil volume is methanol. So if you have 100 liters of oil collect 22 liters of methanol in a seperate container.
5) Very carefully, in an open vented area with respirator and goggles on, add the lye amount you calculated in step 3 into the methanol. For example if you have 100 liters of oil and it titrated at 5 grams per liter and you are using KOH lye (which has a base level of 6.5 grams per liter) then you add 11.5 grams per liter of oil. So for those 100 liters of oil add 1150 grams of KOH into your methanol.
It will get warm and fizzle. If you use KOH-type lye it will fizzle and should dissolve into the methanol easily with minimal rocking of the container, no stirring required. If using NaOH lye you will need to mix it thoroughly which is also more dangerous to you.
Once dissolved this forms a new chemical called methoxide.
6) Very slowly and/or thoroughly add your methoxide to your oil once the oil is at temperature. Again with respirator on in any open-vessel type processor where you can easily breathe the fumes as the heated methoxide and methanol fumes are flammable and dangerous to your health. If you add your methoxide too quickly to can pool and stay at the top of the vessel particularly in a sealed vessel like an appleseed-type processor.
Once added mix the mixture throughly for at least 1 hour (two recommended, more than 2 hours not needed) using some sort of electrical mixer. I have seen all types of mixers including electric trolling boat motors, electric inline pumps that pull from the bottom and add to the top.
One thing to consider is to also turn off your heat at this step though this is not necessary now either.
7) Internal notes to self for this step: The reaction is now happening. At this point you can pull a small sample out of the processor into something like a glass mason jar and watch the glycerin fall out of the mixture, yielding biodiesel on top and by-product glycerin on the bottom. The reaction happens easily and quickly for the first 90% of the reaction but the last 10% is stubborn and any unreacted oil will clog filters, possibly damage engines, etc, so you want to make sure the reaction is complete and thorough. We actually only need 16% methanol (or that is all the reaction consumes) and a lesser amount of KOH/Lye, and less than an hour to stir, but that last 10% is stubborn and needs these factors to thoroughly complete the reaction, though I'm told the wash phase will also pull out unreacted vegetable oil out of the biodiesel product.
8) Turn off mixer after those 2 hours, and let it sit for at least 8 hours preferably 24 hours or a full day as more and more glycerin will continue to fall to the bottom of the processor. It is normal ot have a little unreacted methanol sitting at the very top of the biodiesel (appearing to look like a thin layer of water almost) and that is OK. Also consider turning off your heat as well unless it is quite cold and your product will freeze of gel (below 40 F).
9) Drain off the glycerin layer our of your processor. If you The technique for this varies largely by type of processor you have but what is important is when the switch occurs it will be quickly, and you will see a quick transition in your drain tube from molassis-like glycerin to quick-moving fairly clear biodiesel. The color of the bioidesel varies considerably from dark amber (fairly 'spent' oil) to light colored from oil from Asian restaurants that is fairly new/unused. If you processor has solid glycerin from using NaOH simply turn on your heat again and it will return to liquid form.
10) Pull the biodiesel out of your processor and put into wash tank unless your processor uses your processor also as a wash tank. At this point the biodiesel can be run but can do long term damage to your engine because of invisible contaminents and residual methanol. Some of the contaminents can be filtered out but not all and it is highly recommended to bubble wash your fuel to have it meet ASTM certified biodiesel spec (which is fairly easy to reach once you have bubble washed).
Add about 1:1 ratio water to your biodiesel so 100 liters of oil, add 100l of water to it. The biodiesel is sensitive to violent introductions of water so try to add it "softly" so slow water induction rate or even mist it in. The water is molecularly heavier so it will go to the bottom of the tank and sit there and will already begin to start having a lightly milky appearance to it.
From here, use a bubble washer, which is fish tank pump with some sort of porous gizmo at the end that yields nice small bubbles and turn this on for at least 24 hours. The more small bubbles you have and basically the bubbles bring water to the surface, the water falls, and something about the ionization of the water pulls any contaminants and left over methanol and unreacted oil out of the biodiesel into the water until the water gets saturated. If you start getting emulsification aka "mayonaise" at this step no matter what it means you didn't mix your methoxide and oil throughly in the reaction process. If you introduce the water in too quickly/violently it can also lead to emulsification.
After the water is saturated (24 hours again) discharge of the water (drain is OK) and add another 50-100 litres. This water will have difficulty getting saturated and should stay a light milky color versus the thick milky color of the first batch after 24 hours of washing. Once you turn off (you do not have to discharge this water if you don't want to, you can re-use it for the next batch if your setup allows for this) you must add heat to the biodiesel around 80-90F recommended (if this is your room temp then no heat required) and let it sit another 24 hours to "dry." Once dry, you biodiesel is ready to be run!
I'm going to bed now, photos to come tomorrow..
EDIT never did snap photos before I shipped it off. Sorry about this, perhaps someone can take or post pics?
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