Been doing some simple variations on the test.....

A sample of 'instant clarity' fuel was added first at 3mL to 27 meth...

Perfect clarity instantly.

I increased the test-fuel amount, ending up at 20 mL in the 27 meth....Still perfect clarity, and over ten mins so far, nothing 'settled out'

Wonder what this may tell us....?

I've done similar tests with similar results. I went up to a 50/50 blend before running out of space in my beaker.

Try it with pure triglycerides (new veggie oil) next. The results are interesting.

i think what you have found out is that no matter how much methanol you use if the bio is good its clear if the bio is bad it will give droplets and if its cloudy you have to much sodium or potassium in the meth oxide mix

plugly

Do you guys think 10% too much catalyst would cause the test to cloud?

I'm using KOH and following standard procedure to compensate for the 90% purity...but I've heard the "impurity" is actually NaOH. So it would seem there's really no reason to compensate because the NaOH serves the same purpose in the reaction...let me know what you think.

to much of either KOH or NaOH makes the test cloudy on a 1ltr test i used 11grams of KOH instead of 10 and it gave me a cloudy result and 9 grams gave up oil

plugly

quote:

Originally posted by sharpdan:
Do you guys think 10% too much catalyst would cause the test to cloud?

I'm using KOH and following standard procedure to compensate for the 90% purity...but I've heard the "impurity" is actually NaOH. So it would seem there's really no reason to compensate because the NaOH serves the same purpose in the reaction...let me know what you think.

I've seen it here over and over if you use the same koh for the titration as you do for the reaction you dont have to compensate.

plugly and RickdaTech:

plugly, how sure are you that the cloudiness is due to excess catalyst? I performed a Jan W. test on a final sample that had been created using a base/base/ two stage process, washed and dried. A 5 ml sample of biodiesel was mixed with 45 ml of methanol from a new bottle of HEET that was opened just for this test. The alcohol turned hazy and stayed hazy. After 10 minutes there was no oil, nor were any micro droplets visable, but the haze remained.

This same sample of biodiesel was titrated to both the phenolphthalein and bromophenol blue end points before and after washing and drying. The PTN end point was zero in both cases, indicating no residual catalyst either before or after washing. The Bromo blue end point was 3.5 ml of 0.01N HCl acid before washing and 0.0 ml after washing. Five (5) ml samples of the biodiesel were evaluated in all cases. This means the wash was completely effective in removing the soap.

Based on this single experience, backed up by some lab data, the cloudiness in the methanol could not have been caused by catalyst or soap.

Since there was no oil accumulation in the methanol, I decided to run the pHlip test on a sample of the washed and dried biodiesel.

The results of the pHlip test were: Indicator color remained cherry red with no turbidity present, there was no turdity in the biodiesel, and a partial mirror surface formed at the interface of the indicator and the biodiesel. The interface was marred by some very small and small globules that covered about half the mirror surface.

My analysis says this sample contained no catalyst, contained no soap, contained no triglycerides, but did contain a small amount of mono- and di- glycerides.

The fact that the PTN titration indicated no catalyst present prior to the wash would mean that not enough catalyst was used to drive the reaction to completion. All the test data and observations support this conclusion. (Why there would be any FFA in the second base stage to form soap raises a whole series of additional questions. Neutral is probably exactly correct when he hypothesises that the catalyst will continue to react to form soap as long as catalyst is present. But, I can leave this subject till another time.)

The sample is probably not full ASTM conversion, but damned close. I am considering sending a sample to Magellan Monday morning to have a GC test run. If I do I will report back with the results.

My opinion is that we can learn a lot from both tests if we learn to properly interpret the data. Both the Jan W. test and the pHlip test provide useful and meaningful data.

Hi guys,
I've been using the Jan's methanol test for about a year with very good results. In fact I only use my titration to get a "starting point". Then I do a graduated series of test batches, using methanol tests on each, to figure out the amount of NaOH for my 50 gallon batches. You will be suprised how often you get an incomplete reaction with the standard " titration + 3.5 or 4 or 5 grams" of caustic. This is because there is no way to know exactly what you are starting with. Since the 3.5 or 4 or 5 grams is based on an average amount of short, medium, and long chain triglycerides in the oil, it can never be truly accurate. It is, quite frankly, a guess. If your oil is mostly short chains, there will be more individual molecules to react, so a titration + a set number (3.5 or 4 or 5) will be under reacted. The opposite is true for a predominance of long chain triglycerides. When a reaction is either overkilled with lye or under reacted, everyone blames the titration accuracy. The best, most accurate titration in the world plus what is litteraly a guess, an estimation, cannot possibly give 100% accurate results. The methanol test gives us the necessary feedback loop to make very good fuel without the nasty surprises. I tried to post this explanation to JTF about 6 months ago and The BioGod Himself (All Hail the Magnificent!) implied (outright told me) I was a moron!
Anyway, I have never seen any evidence of the lye amount causing a false bad test. Any water in the methanol or biodiesel will cause a bad test though. Therefore I only use virgin methanol for the methanol test. Happy Biodieseling! Chris Rice

all i can say is this ive done nearly 20 1 ltr tests using different amounts of methanol and KOH to get all the info i need and when i add more KOH than needed i get cloudy test if you wish not to believe its that just add more methanol or mix a cloudy 1 ltr batch with glycerin it will clear all depending on how much over you have added over but it will clear in end.
i have wvo that is 10gram KOH i did a batch with 2x the amount of KOH thats 20grams way over the top it was cloudy but by adding just glycerin i got it to clear took a bit of the stuff BUT IT DID clear.
even with all the KOH it passed the test till i removed the methanol
the test will pass all stages until you remove the methanol then it will fail the Jan test.

i can do 100ltrs single stage batchs and my tests now pass every time start to finish

please read my other post on this test it will give the amounts of chemicals i used for all the tests these are important to getting all tests to pass

plugly

quote:

Originally posted by plugly:
well where do i start
i run a 1 ltr test batch using KOH
did shake left to settle then tested 27/3 it was crystal clear,
i then washed and dryed still crystal clear then did same test again 27/3 its hazey but no oil or bio in bottom of jar

is it good or bad

plugly

plugly, your report of 11 July 2006 on your results on dried and washed biodiesel look very similar to my recent report. I wonder what variable is introduced in the drying and washing stage that is not present earlier. Or are we missing something else that bears on the results?

My test results are similar to plugly's results. My testing was limited to good biodiesel and biodiesel contaminated with triglycerides and good biodiesel contaminated with underconverted biodiesel. I have not tested with bodiesel contaminated with only mono or di glycerides. The basic results are that it does not matter if your a bit off in measuring either the methanol or biodiesel, it will give the same results. If you want to measure how much falls out then you have to be very precise on how much oil you put in.

plugly, are you seeing the cloudy on finished washed and dried biodiesel made with extra caustic?

I have been able to get a solid precipitate to fall out from tests that go cloudy. After a couple of days it clears and has this very small sand looking stuff in the bottom. Don't know what it is.

Just pulling a possible theory out of my backside, if excess catalyst is present, it causes the reaction to start up again, possibly making more soap and releasing water that causes the test to go cloudy?

The pHLip test is not very sensitive to catalyst. It take a lot of excess to show up. It also takes a lot of catalyst to fail the ash test. The results you describe on the pHLip test indicate it is very near astm spec. It might actually pass GC testing.

quote:

Originally posted by plugly:

the test will pass all stages until you remove the methanol then it will fail the Jan test.

plugly

I should have read closer, how are you removing the methanol? By water washing or evaporation/boiling or zeolites or some other method?

I did a series of Jan W. tests on various samples lying around. After the last one, I just left the sample on the bench for a couple of weeks. As the methanol evaporated and/or absorbed moisture, bio started to drop out. Over time the volume of bio increased as if the meth were then saturated; then the meth and the bio sat side by side in the flask as the densities became equal; and finally the clear liquid was below the bio. No further changes took place so I drew up the liquid (water) into a syringe and found 2ml from an initial meth volume of 27ml. Maybe this is indicative of how much water can be absorbed.

quote:

Originally posted by fabricator:

quote:

Originally posted by sharpdan:
Do you guys think 10% too much catalyst would cause the test to cloud?

I'm using KOH and following standard procedure to compensate for the 90% purity...but I've heard the "impurity" is actually NaOH. So it would seem there's really no reason to compensate because the NaOH serves the same purpose in the reaction...let me know what you think.

I've seen it here over and over if you use the same koh for the titration as you do for the reaction you dont have to compensate.

You're right...I don't compensate for the titration amount because I make the titration solution with the catalyst I'm using.

However, it seems like common practice to compensate for the "impurity" in the base amount...

I guess the base amount may be a guess anyway...based on one of the other posts today.

Hi folks,

I'm after some help. What are your thoughts on these results? The bio is from a problem batch which emulsifies easily when washing.

quote:

Dissolve 3ml of bio into 27ml of Methanol in a 75ml jar with a cap.
Results = Clouded up when bio was added. As soon as I swirled it around it cleared right up. I ended up with a clear liquid with a slightly yellowish tinge to it. 1 hour later nothing had changed. No drop-out at the bottom, nothing in the middle, no particulate matter, nothing at the top.

The same results were had with 3ml bd and 20ml methanol.

The same results were had with washed but not fully dried bio.

This is from another post, thought you folks might be able to throw some light on what could be happening.

Graham,

Both the "3ml in 27ml" and the "3ml in 20ml" reactions indicate good biodiesel.

A bit of concern is raised by the "washed but not fully dried bio" comment. Most of the information in the previous posts says water in the sample will screw up the results. Maybe your sample was drier than you thought.

When this test is done on unwashed BD, does it give false pos., false neg. or OK results? Anyone compared unwashed results to washed and dried results?

Thanks,

Andrew

Hopefully this thread is not dead. I am somewhat new to BD homebrewing and read this topic from the beginning. Forgive my ignorance but when you guys refer to CG testing, what is this? It sounds like something that needs to be performed by a lab. What does CG stand for?

Thanks

Hello seldomseen

GC= Gas Chromatography.

Thanks for the definition. What does Gas Chromatography test for? Completion of reaction? Different levels of things in the BD?

Thanks