quote:

Originally posted by Tilly:
Hello Rick

Of course the instructions do say to perform the procedure at Room Temperature

But you are correct, as with the Phlip test which costs $5 and does not guarantee ASTM Quality biodiesel, passing the Warnqvest test does not guarantee ASTM conversion.

I feel that if a commercial manufacturer is relying on either the Warnqvest Test or the Phlip test as his sole means of determining whether he has ASTM standard fuel then his operation is not nearly up to scratch and deserves to get bitten on the backside.

As far as I know, there is only one correct testing regime for checking whether your fuel is of ASTM standard or not, and I do not believe either the Phlip test or the Warnqvest test is mentioned in any of these tests.

Hi Tilly, we seem to agree on more than you thought.

Rick,

quote:

It's close enough for homebrew most of the time

If people are passing 3/27 with fuel that is uwashed, and allowed to cool to 68f or cooler and allowing the test to settle for 30 min., then they are probably getting pretty close or under ASTM. Of course, variations caused by feedstock, how much washing improves each batch, and the mono/di/tri ratios will lead to some margin of error.

Which do you think would be better, to run tests and see at what temp. the three samples I have GC data on fail, or to change the ration of BD to methanol? I am leaning towards testing temps.

Tilly, your thoughts?

Andrew

Hello Andrew

That would be a start.
You also need to know the purity of the methanol you are doing the test with to be meaningful.

Tilly,

quote:

You also need to know the purity of the methanol you are doing the test with to be meaningful.

Yes, for it to meaningful to others, particularly people who can't get HEET.

It is meaningful to me, as it is, since I can compare to the known samples using the same methanol and temp.

Andrew

Hello Andrew

quote:

Originally posted by Andrew Morris:
Tilly,
Yes, for it to meaningful to others, particularly people who can't get HEET.
It is meaningful to me, as it is, since I can compare to the known samples using the same methanol and temp.
Andrew

Yes, if that is all you are concerned about and until you run out of that particular batch number of HEET or until you open it up too many times.

Tilly,

Yes, since there may be variations in HEET, I re-do the refferance sample test each time. Gladly, the test on costs a few cents.

Andrew

So I just did my first 3/27 test, on a batch that I expected to fall a bit short (and it did 98% conversion or so), and came up with some interesting results (and a few questions).

If one is using 3ml of BD for the test, then I am assuming that one can take the rough volume of the precipitating oil in mm**3, and use that as a guide to conversion percentage (precip volume / 3000 * 100 = percentage unconverted).

Is this the general consensus on this? If so it would mean that a volume of 7.2mm**3 or less would roughly be ASTM. Not a very large drop on the bottom of the jar.

ASTM aside, is there a general conversion figure that homebrewers can feel comfortable using in DI or IDI engines without anxiety?

Another point of interest, I first did the test with methanol that was at roughly 20F (right from my drum in the shed). Plan was to warm it up, but interestingly the methanol cleared very quickly, but a bunch of "snow flakes" appeared on the bottom. No doubt solid BD or other fats. As the mixture warmed I could dissolve the precipitate and do a normal test. I mention this only as it seemed it might has some potential for testing cold weather properties of BD more quickly than putting samples in the cooler.

Steve,

quote:

If one is using 3ml of BD for the test, then I am assuming that one can take the rough volume of the precipitating oil in mm**3, and use that as a guide to conversion percentage (precip volume / 3000 * 100 = percentage unconverted).

Is this the general consensus on this? If so it would mean that a volume of 7.2mm**3 or less would roughly be ASTM. Not a very large drop on the bottom of the jar.

I think all would agree that the presence or absence of fallout relates to the degree of conversion. The amount of fallout, in my oppinion, does not relate directly, as a percent of the original volume, to the percent conversion. I have not seen data to support such a relationship. Others may disagree.

This test is very temp. dependant.

Andrew

Hi Tilly
Can you explain to me the science behind this variation on the 3/27 test? Capn Andy's Forced Failure Test

I am unclear how cooling a test changes the conversion. Sounds like voodoo to me.

fatkid,

I am looking for someone who is both skeptical and open minded to test it.

Make two batches that will both pass. Do something to one which should make it clealy more converted. Chill and test. See if the one which you think should be converted better has less fallout at low temp.

By the way, I based the idea on the observation that at colder temps, fuel fails while the same fuel passes fine in the warm. Example: Test in the afternoon, pass. Test the same fuel the next morning, fail. Lots of people report this. Most things are more soluable at higher temps. This is why we heat to wash. Hot water holds more soap. It is also why the test tells you to do it at room temp.

So, please test and give data that supports or contradicts the testing. That is what is great about the boards.

Andrew

quote:

Originally posted by Andrew Morris:
fatkid,

I am looking for someone who is both skeptical and open minded to test it.

Make two batches that will both pass. Do something to one which should make it clealy more converted. Chill and test. See if the one which you think should be converted better has less fallout at low temp.

By the way, I based the idea on the observation that at colder temps, fuel fails while the same fuel passes fine in the warm. Example: Test in the afternoon, pass. Test the same fuel the next morning, fail. Lots of people report this. Most things are more soluable at higher temps. This is why we heat to wash. Hot water holds more soap. It is also why the test tells you to do it at room temp.

So, please test and give data that supports or contradicts the testing. That is what is great about the boards.

Andrew

I agree that this test should be run. Preferably by several people. I'll put it on my list o' things to do.

However, one thing I'm still puzzled by theoretically: if it is merely a matter of solubility being influenced by temps, then increasing the ratio of biodiesel to methanol should similarly push the envelope, shouldn't it?

Here are two test results from the same batch of BD (hope the pic comes thru).

On the left is a pHLip test. Basically clear results with one bubble at the interface layer. Otherwise the interface laye is clear. FWIW the layer at first had a bunch of bubbles, but over the next 10 mins they all popped but this one. It too popped several hours later.

On the left 3/27 test results. All clear except for a tiny (smaller than a bb) size clump of "stuff," visible at the bottom in the center nearest to you.

Thought it might be useful to post the results of these two tests on the same BD.

PICT0148.JPG (111 KB, 86 downloads) Test results pic

George,

quote:

However, one thing I'm still puzzled by theoretically: if it is merely a matter of solubility being influenced by temps, then increasing the ratio of biodiesel to methanol should similarly push the envelope, shouldn't it?

It seems that it should, but so far I don't see the nice gradual change I see with temp. I will look again, when I have a chance.

Andrew

Steve777,

Pic is good. The bubble on phlip is meaningless. So says Randal. The clarity of the fuel layer is key, along with the shiny interface.

What temp. was that 3/27 and how long did you let it settle? Also, with what methanol?

Andrew

Okay, I think I am beginning to understand, maybe use the 3/27 as more than just a strict yes/no test but rather try to say something more to some sort of 'degree'of conversion-sorry for the pun. My only problem with the logic at this point is that the assumption is that solubility will remain constant between two samples of different conversion. I would think that you would have to establish first that solubility between samples of disparate conversion would be identical. If it works this would be nice addition to the general test.

All liquids in the 3/27 were at 50F approximately. At the point the pic was taken it had settled for several hours...

quote:

Pic is good. The bubble on phlip is meaningless. So says Randal. The clarity of the fuel layer is key, along with the shiny interface.

What temp. was that 3/27 and how long did you let it settle? Also, with what methanol?

Andrew

Steve777,

quote:

All liquids in the 3/27 were at 50F approximately. At the point the pic was taken it had settled for several hours...

Your fuel is pretty well reacted then, but I guess you knew that.

Andrew

quote:

Originally posted by fatkid: (SNIP) My only problem with the logic at this point is that the assumption is that solubility will remain constant between two samples of different conversion. I would think that you would have to establish first that solubility between samples of disparate conversion would be identical. If it works this would be nice addition to the general test.

Fatkid,

If I understand your problem, you're saying that there is an underlying assumption that has nothing to do with whether the samples have different conversion or not...just that insolubility of glycerides is a constant over time?

This is an assumption, but it seems a valid one if you control the variables: temperature, purity of methanol, etc.

George and Fatkid,

quote:

ust that insolubility of glycerides is a constant over time?

This is an assumption, but it seems a valid one if you control the variables: temperature, purity of methanol, etc.

Agreed, and, in particular, IMO, feedstock needs to remain constant if you want to compare batch to batch using this method.

Andrew

By feedstock remaining constant, do you mean soy v. canola, or titration, or what?

I'm not understanding something (as usual). Are you saying that a 99.9% conversion feedstock A would pass Warnqvist at 68F, but the same conversion feedstock B might not pass at the same temp? If it is glycerides that precipitate out, why would where they came from matter?