For the first time in ages, I looked at the JTF site and found Jan's entry there about the test..
Here it is...
Jan Warnqvist uses this test:
"Take exactly 25 ml of biodiesel and dissolve it in exactly 225 ml of methanol in a measuring glass.
"The biodiesel should be fully soluble in the methanol, forming a clear bright phase. If not, there is pollution in the biodiesel. Each ml of undissolved material corresponds to 4% by volume. Is there any undissolved material at the bottom of the measuring glass? If there is, your reaction is not complete and this is causing you trouble with the water test.
"This method does not cover every aspect of quality, but it gives a hint. It is valid only for biodiesel made from vegetable and animal oils. It is not valid for biodiesel made from oils with a very wide fatty acid pattern, such as fish oils."
"Each ml of undissolved material corresponds to 4% by volume....."
This looks interesting...Could do something with this, Just need to accurately measure against my known 78% stuff, and see how it works out, then make some 'blends' of 78% and my 'good' stuff to assess if a practical easy and quantifiable test for esters is possible using this proceedure.
Unfortunately, it doesnt go on to say exactly what the 4% is....
I'm always stunned by shade tree chemists and their discoveries.
Do you suppose they wake up at 3:00 a.m. screaming "eureka!!!" ???
Though your argument is very clever, I don't think it will lead to the results you desire. gandhi
OK so, if I have a little BB sized bit of bio at the bottom of the jar does this mean If my oil titrates the same next time I should kick the koh up a little and process a little longer?
That's the way it looks to me.
I asked this question in another thread but got no replies so I'll ask it here..
How important are the volumes? Is it really important to measure out a perfect 27ml of meth and 3ml of bio? What if I get 28ml of meth? or 2.9ml of bio? And why is it so important?
If I can not get exact numbers, which of the 2 evils is better? To much or to little?
I'm going to the shop now and going to try this test..
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Looking at the way the test works...(I guess, Not really sure here....)
Good 100% Esters (something very difficult to make....)
3 mL of 100%, should dissolve completely in 27 mL near pure meth with none left over, which would otherwise 'come out of solution' IE, its a 'Saturated Solution'
IF for some low conversion reason or impurities, this upsets the ballance, and the 'Impurities' such as the Glycerides will cloud the meth, and will settle out over time, (Say, an hour or so, depending on how much glycerides/impurities are present) leaving only the esters in solution with the meth....
I guess the measurements are pretty critical, I used the same sort of gear for measurement as Tilly recommended, but used a glass syringe of 1 mL capacity, three times for the 3 mL, I used a 20 mL syringe for the meth in two stages, all placed in a 50 mL glass precision measure vessel with a bulbous base (I have quite a few of these, They make excellent vessels for titration and experiments like this!) Any convenient CLEAN glass vessel could be used to hold the mixture under test...
5 mL syringes for childrens meds measurement are cheap and easy to get, and I believe you can easily get larger fairly easily too...
There are least two reasons why you should try to accurately measure the recipe amounts: reproducibility and comparability.
If the recipe calls for 27 ml you should try to measure 27 ml. It is understood, when giving a volumetric measurement for home brew biodieselers (sp?), that the laboratory skills will differ from home brewer to home brewer. So in that regard the measurement should not be interpretted as exact to 3 decimal places.
In your set up you should select an appropriate measuring device and measure 27 ml to your standards. Don't worry too much, you will probably never hit it exactly. Each time you measure 27 ml there will be a slight variance between 27 ml and what you actualy measured. And the variance is just about as likely to be slightly over as slightly under. If you could plot the variances over time you would see that the average measurement is very, very close to 27 ml. You may be very skilled in a lab setting and you would find that your average variance is very small (if you could measure variances), say 0.2 ml. Someone less skilled in the lab may find his average variance to be 1.5 ml. But both home brewers' average measurements would be very close to 27 ml because the variances are both above and below your target measurement.
Comparability is also important. By exercising care in measuring and always using the same recipe, then you know that different results you obtain from different biodiesels samples are based on your BD and process and not your lab technique.
Also, when several different people run the test and report the results here, then there is good probability that different results are based on differences in oil and BD, not lab technique.
For instance: in the above post, fabricator said he observed "a little BB sized bit of bio". Although he did not say he used 27 ml of methanol and 3 ml of BD, that is the assumption. If he had used 225 ml of methanol and 25 ml of BD and reported "a little BB sized bit of bio", then he would have been describing a process that was lot more efficient than the one he reported on.
I hope this helps.
OK! I tried this on a batch I just got through with. I used 27 ml of meth, 3 ml of bio. When I swirled, it immediately cleared up. Nothing has dropped out as of yet. One thing interesting though, I brought it into the house at about 74 deg and it clouded up just a bit from where it was. It was in the 80's in the shop where I did the test. Anyone seen anything like this? Is it anything to be concerned over? Like I said, so far nothing has dropped out. I will keep watching it. The oil is soybean.
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When I swirled, it immediately cleared up. Nothing has dropped out as of yet. One thing interesting though, I brought it into the house at about 74 deg and it clouded up just a bit from where it was. It was in the 80's in the shop where I did the test. Anyone seen anything like this? Is it anything to be concerned over? Like I said, so far nothing has dropped out. I will keep watching it. The oil is soybean.
The methanol may have pulled in some water from the air?? Leave it set a few hours and see what it looks like then.
This test came at the perfect time, I have had some issues with my fuel filters, nothing real bad but have still had to watch the gauge and change the filters after a couple thousand miles.
Now for the problem........
I did the test on a couple batches, the ones i did the 5%glyc prewash on didnt pass, the methanol turned kinda cloudy and didnt clear right away, after setting for several hours i had a little oil on the bottom, just kinda whispy.
I did a load of the same oil and it titrated the same , HOWEVER this time i didn't do the 5% glyc prewash. When i tested this it was clear as a bell and nothing dropped out....
Anybody had any issues with the bd from the 5%glyc prewash using this test????????
This was the only varible i could think of and i dont like it very much.
I have about the same results, and I used the prewash also, I dont have any that was not prewashed to try it on though, my bio is clear as a bell, I have had a few jars full for two months still crystal clear with nothing at the bottom of the jar.
When i did the test on the new, No prewash, the methanol only was cloudy when i swirled it around.
I heald it up to the window and could see the barn through the side of the jar, it looked as clear as it did when i first put the methanol in the jar.
The only 2 batches of bd that i have left that i did the prewash on clouded up and i could not see through the side of the jar.
Murphy, I think you chickened out doing the prewash on your first batch?? If you still have a sample of that, have you tried a test on it??
And how did your bio do that was prewashed??
As a matter of routine, I use the pre-wash at around 5% on all batches...
My 'good' fuel is crystal-clear, and my not-so-good fuel is cloudy....
Both were Pre-washed....
Was your BioDiesel dried before doing the 'Meth-Test'?
The Pre-wash will leave some moisture in the fuel and could give the clouds you see if it was straight from the reactor Post, Pre-wash, prior to washing/drying...
I still have a sample of it sitting in my front window.. It went from an iced tea look to a yellowish color over the past month.. Its in an open top container.. Its clear as a bell.. I even froze it once to see what would happen..
I did not get a chance to try out this new test..I wanted to do it today but was caught up on a bunch of shop cleaning and organizing. I have to stay clean and organized or I can't get anything done.
I'll be trying this test Sunday on 2 pre-wash samples and my first non-prewash large batch sample.
I'm beginning to come to the realization that if you have good heat, good circulation and use the correct amount of chemicals, ASTM fuel is almost a gaurantee so long as you wash and dry the crap out of it.. While this might be a false assumption, it seems to me from reading this forum that when people have problems it almost always goes back to something they took a short-cut on or didnt do correctly..
I'm a bit anxious to try this test.. and a little pissed off that I didnt get a chance to do it today..
I also had to titrate about 2 dozen oil samples I've gotten from potential sources over the past month or so.. I dont like talking to the manager/owners without knowing if I even want thier oil... Someone posted in another thread "what's the worst titration you've had" and I responded something like 5 koh.. Well, I got one sample today were the oil was very clear, smelled good, no crap in it and was very liquidy.. I stopped adding my solution when it went past 15. I knew I'd blow it off when it went past 5 or 6 but was curious.. got to 15 and just said screw it.. Blanked my titration and did it twice just to be sure everything was ok.. What a good way to get experience.. You just can't tell by looking at oil..
I got a sample from a mexican place also.. Titrated at .4 and .5.. I'll have to go there this week!!!
All i've been able to think about the past day or two is trying this new quality test.. Just havent gotten to it yet but I will sunday for sure.. (I think)
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Hi HC11 ,The bd i tested were all washed well and dried. They are all crystal clear and the truck runs great except for the issue with the filters.
I use a 10 micron goldenrod hooked to a 2 micron bio tech filter and circulate the cold bd through this setup for an hour or 2, and it gets filtered again before putting in the truck, 2 micron.
Murphy, I am very careful in my process, from dewatering the oil to doing the titrations, at least 3 times,allways do the blank and keep doing it till i get numbers that match.
I dont take shortcuts, except ones that are proven, like the prewash. It makes washing sooo easy. I hope i am wrong about the prewash, that is why i started doing the batches without the prewash, to see if the problems ends..... That is why i am happy this test came along, at the perfect time.
When i bought my KOH, the mfg said it was 90% and that is what i have figured on, maybe it is not?
I will wait to see how this shakes out, and what is happening with the other homebrewers using this test.
Thankyou Tilly for posting this.
I've tried the test and so far I like it. Be sure to watch the quality of your methanol. Small ammounts of water in the methanol make drastic changes in the results.
I received this e-mail from Jan Warnqvist.
I am complimented by the attention of this simple test.
First one question that came up: Wide fatty acid patterns. this test is based upon that the biodiesel mainly consists from C18 fatty acid chains.
Fish oil has a chain pattern from C10 - C26, and since the proportional polarity of these chains are very different, it is more than likely that triglycerides consisting from short chains will enter the methanol phase and biodiesel consisting from very long chains will drop out of the methanol phase. in this case the test is of no value. I do not know the fatty acid composition of seal oil, oil from algae and so on.A question mark should also be put for high eurucic acid oils.
The test can be adapted for mass determination: 200g of methanol and approx 20 g of biodiesel. Stir and leave to settle in a flask with a tap in the bottom. Take out the settled phase and measure it on a balancer with high accuracy. The methanol insolubility is calculated : MIs = b/a where
MIs = Methanol insolubility in % by mass
a = the mass of biodiesel put in
b= the mass of the dropped out phase"
1mL (3% by volume) of distilled water added to a passing test was enough to cause a precipitate to fall out giving a false indication.
Has anyone recorded the temperature of the methanol in their test?
I redid the test using a more sensitive titration syringe with .01mL divisions and found it only took 0.49mL (1.8%) by volume to change the results from passing to failing.
One of Mickeys tests was performed with methanol at around 5deg C.
Temp does not seem to make much of a difference.
Ok so after I read Ricks post I redid the test being sure to be ultra accurate with my measurements. I went from a fail to a pass this time, clear meth with no fallout. So I guess the measurements are quite critical.
Great news!!!!!!!!!!!!!! you kids been busy while I was gone.
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