DVA,

quote:

I tried doing the 3/27 test with another sample taken from the same batch as the one mentioned above. This time though, I heated the sample (100 cc) to 75c for 15 minutes before taking out the 3 cc for testing. The result was the same.

What was that result again?

I am aware that people observe glycerine dropping out of BD over time.

quote:

By 'clear visible line of seperation' I take it that you are refering to the line of seperation between the bio and the glycerine layer during reaction. This seem a little odd to me as the glycering tends to fall out over an extended period (weeks ?) after the seperation line becomes visible.
This can easily be demonstrated if, once the line has become visible, you pour-off all the bio from above it into a new jar. A new seperation will soon become apparent as the glyc' continues to fall out.
regards
dva

Yes, glycerine settles and then I do the test. About 15 min. after I take the sample from the running processor. The result has matched the washed and dried result EVERY TIME. The only "exception" is that in a few cases (less than 5) I see better results with washed and dried. These are on the ones which are right on the cusp of pass/fail. I done over 200 tests and counting...

That is the data I can collect. So far. Now, if you are looking for an explanation of that result, it seems that glycerin is soluable in methanol. It falls out of BD, but not methanol.

Someone, sorry, I forget who, did a test showing this.

Personally, I like to try, at least initially, to keep the observed data seperate in my mind from the explanation. Seems to help me anyway.

Andrew

Andrew Morris,
re,

quote:

What was that result again?

Page 19. posted 2nd June.

regards
dva

DVA,

I am still not sure I understand the result you are pointing to and how it relates to 3/27.

I re-read that post and see that you are testing when glycerine fall out of BD, right?

How exactly does that relate to 3/27?

Andrew

sorry guys, got a question about 27/3 test and ethylesters:

does anyone knows how to calculate the good ratio (ester/methanol) for an ethylester ?

Bob,

Can you please explain a little more about what info you need?

Andrew

yep

i'd need to test the quality of my ethyl ester but guys told me the 27/3 test wasn't fitted for ethylesters (solubility difference with methylesters) and that the good ratio to test ethyl ester was maybe 27/4 or anything else...

what do you think of this ?

Bob,

Thanks for clarifying.

I have done exactly 0 personal research with ethyl ester. So, I will guess, and hopefully someone who does make ethyl ester will chime in...

I think (guess) the the 3/27 test using methanol should work the same, or almost the same with ethyl esters. The triglycerides are what we are really testing in this test, and they are the same, regardess of which alkyl group is used in the ester. Same goes for mono's and di's.

What could mess it up is co-solvent effects, if ethyl ester is better at keeping TG, DG and MG in solution than methy ester. Don't think so, but very well could be.

I suggest that you test the test...

Make a sample batch that you know is good conversion - use enough excess of cat and alk and mix enugh to be sure. Wash and dry. Test. Then make a sample batch you know will be under reacted. Not enough alk and cat should do it. Wash and dry. Compare the results. Let us know what you see.

Also, I suggest posting a question with a heading about ethanol, so you get the ethanol users to respond.

Keep us posted with what you figure out though.

Andrew

thanks Andrew

first: finding methanol

then: i 'll tell you the results

ciao

bob_isat

A short thread about clear or cloudy test results.

Andrew

This is what a FAILED 3/27 test looks like...


Thought some would enjoy.
-Graydon

Graydon,

Tell us whose fuel that was, OK?

Andrew

I hate to sound like a broken record but I am asking for samples of people's biodiesel so that I can make a correlation between volume of dropout and the percent conversion of biodiesel.

It is a senior project for my college graduation and I'd be glad to give the results of the D6584 test since I will be using it go get conversion. If anyone would be willing to donate, go to my thread here . It has the Chain of Custody Form I'm using. Thank you to anyone who donates. I will add you as part of my senior project and your name will be added to the poster and senior project section.

Bump

This thread should be a sticky

I'm not sure if this fits in here or not but is specific gravity a good indicator of conversion? If it is, what should it be? If not, why not? Then again, the 3/27 test is so easy why bother?

Hello Keith

No, SG is not a good indication of conversion.
The SG of different oils vary and even the same type of oil from different batches.
This leads to a variation of the SG of the Biodiesel produced.

So while biodiesel from one batch of oil might have very high conversion and an SG of 0.87, Biodiesel made from another batch of oil might have an SG of 0.87 and not have acceptable conversion.

Also, the difference in SG between unreacted oil and biodiesel is not very much.

A much better test is Viscosity. You can gain a LOT of information by comparing viscosity.
HAve a look at the World Famous Dr Pepper Viscosimeter (Pat Pend) for more information.

Hello Superorb,

This is the 3/27 test. Go to the first page.
This thread should be a sticky.

Okay,
I have to chime in here. I have been reading this thread all day, well on and off. I started from the beginning and got to page 11. That is king of where the new information seemed to start running out.
I am working at the University of Central Oklahoma and we have been making bio-d for a while now and have just recently started using this test. We are using the 18/2 method because that is what fits in our test vials.
We are starting with some pretty nasty stuff, most of it is titrating over 100 (we are using the drop method, not the milliliter method).
We have yet to make a small batch that will pass this test. I am currently working on a sample that I have reacted 3 times and it will not pass the tests. Each time we get a little less precipitant, but it is still there, as well as cloudy top layer. The reactions are using a base of 5 + titration, and 22% methanol (after reading sounds like we may need to go to 25%).

Any ideas? Can provide pictures if you wish.

We have made and used over 800 gallons with no problems, but are looking to make a better quality product.

Thanks for any and all replies.

If you are having issues with conversion, consider doing a search for base/base process, or read this article on CBT.

This process will give higher conversion for the same amount of methanol.

Remeber, when doing 3/27, control the temp. I like 68F.

Here is another tid bit of information. I would love to hear your thoughts.

I just sacrificed one of the "Reference" vials of our pHlip test kits. We have been using this test for a while now and we have several laying around.

I used the biodiesel on the top to do one of these test on.
Guess what? IT FAILED!!!!! The meth was clear but it did not dissolve. I wonder how good their test actually is if the biod-d their using as a reference will not pass this test.
Your thoughts?

(I also posted this as a new topic to see what sort of other reply I get.)