As most of you know, I have a contamination problem and its causing massive headaches when I wash. I reacted a new batch of oil that came from a NON contaminated source. I am now washing this batch and its showing some signs of contamination.. I'm thinking it was residue from the problem oil left in the reactor, transfer lines, etc etc. The symptoms are not nearly as severe as the problem batch but they are there..

Anyhow, what I am finding is that I am getting crystal clear water out the bottom of my wash tank.. You would think its time to dry yes? NOPE.. I tried drying a 250ml sample on a hot plate.. I had to heat it to 200 degF and stir the crap out of it just to get it to clear up and there are many droplets of water at the bottom and floating around.. So I poured it from beaker to beaker to simulate spraying.. still water in there..
In the barrel between the water and bio is also plenty of the dreaded white stuff.. Soap? About 6 inches of it in my barrel between the biodiesel and the crystal clear water below it on the problem batch and about 1 inch in the new batch. I used the misting nozzles and let them go for about 8 gallons.. all the water at the bottom is clear as a bell, just as it was when it went in.. The bio on top is very light colored orange juice and does not look like its done. (not the darkish stuff I'm used to seeing when its ready to be dried) So, the water is not removing whatever is causing the problem..

Would this work? I want to add 2 Liters of methanol to the batch.. maybe the meth will help whatever is in there dissolve back into solution and let the water carry it out.. By the way, my batch in the wash barrel is about 35 gallons.

Any ideas? Suggestions? Comments?

Hello Murphy
In my experience, If you take your biodiesel straight from the washer to the stove top there will be a lot of water drop out to the bottom of the pan.
The biodiesel will also cloud back up when it cools.
In my experience it takes heating a second time before it will stay clear.

What's the difference between heating once for a half hour or twice for 15 minutes? Or did I misunderstand what you're saying?


Also, as for the problem oil, will the methanol trick work to redisolve the soap so that the water can carry it out? I have 6 inches of emulsified oil/soap and absolutly clear water at the bottom of it..

Hello Murphy

I do not know, I never tried it. I always let the sun do the job.

Hi Murphy

I suspect you have an incomplete reaction AND may be washing too aggressively.

If your water is clear you have removed the soap successfully.

Titrate again using the SAME batch of lye you reacted with to make a FRESH 0.1% lye solution.
Do you get a higher titration number than you expected?

Have you tried a VERY gentle wash?

quote:

Originally posted by GrahamLaming:
Hi Murphy

I suspect you have an incomplete reaction AND may be washing too aggressively.

If your water is clear you have removed the soap successfully.

Titrate again using the SAME batch of lye you reacted with to make a FRESH 0.1% lye solution.
Do you get a higher titration number than you expected?

Have you tried a VERY gentle wash?

Graham,
Thanks but all that is a mute point.. I've eliminated all those possibilities. I made a 1L test batch of Non-contaminated oil, and a 1L test of my contaminated oil. The Non-contaminated batch came out perfectly and the contaminated oil did exactly what it did in my wash tank..

I also did another test.. Using known good raw WVO, I mixed 250ml of the WVO with 250ml of water. Shook the crap out of it. I had perfect seperation in just a few minutes with a clear sharp seperation line with the non-contaminated oil.. I did this experiment with 4 different WVO pickup locations. (Call em my Favorite 4) I also did this same experiment with the container of problem oil I have and I got a huge emulsion. There was about 150ml of oil on top and the rest was yogurt and stayed that way. 10 days later, it is still the same. It has not broken.

You know what is really bugging me about all this? Every time I talk about this problem oil, all the experts revert back to thinking its something I did wrong as if I'm a "first batch newbie" or something. While I realize anyone can make a mistake, I've been trying to solve this problem for 2 freaking weeks and have done about a gazzillion experiments to try to fix it. The very first thing I did when things went wrong was to revert back to revert back to the basics, check chemicals with 1 Liter batches and double and triple check my work.

Would the methanol idea work?

Murphy,

What did the problem oil titrate at?

What did the good oil titrate at?

Did you try the Jan Warnqvist test?

quote:

Would the methanol idea work?

Murphy, why not scoop out a liter of the problem stuff and do a test batch on it and see how it turns out?

Steved,

Thanks! Is there any special requirements to ship vegetable oil?

I would love to see someone take a crack at this stuff..

I'm going to try a few more experiments tonight.
Experiment 1:
Mix glycerin into wash tank to break emulsion and re-wash the batch. My only concern with this technique is that while it may break the emulsion the batch will need to be re-washed and if whatever caused the emulsion is still in there, I'm just going to end up with the same problem again.

Experiment 2.
Mix in glycerin with the raw WVO before reacting it and see if the glycerin removes the contamination.

Should be interesting to find out if either of these work.

quote:

Originally posted by GrahamLaming:
Murphy,

What did the problem oil titrate at?

What did the good oil titrate at?

The problem oil titrates at 4 KOH.
The good oil titrates between 2.7 and 4.9 KOH depending on which of the favorite 4 I get it from.

Thanks Graham..

Have you tried the Warnqvist test?

quote:

Originally posted by 01stroker:

quote:

Would the methanol idea work?

Murphy, why not scoop out a liter of the problem stuff and do a test batch on it and see how it turns out?

Oh I'm so way past that... I've done about 2 dozen test batches on both known good oil and the contaminated stuff.
When I first started all this I had to analyize to find out if:

1. Did I screw up the math?
Answer = NO

2. Did I get a fresh batch of bad chemical(s)?
Answer = NO

3. Is this contamination isolated to my current WVO collection container or is it from one of my favorite 4 collection points.
Answer = Its isolated to my WVO collection container. (Note: Of the 200+ gallons of oil in the WVO collection container, there is about 30 or 40 gallons of oil from new sources)

4. Could this problem oil just require a more gentle approach to washing or does it really have a contamination.
Answer = It really has a contamination

quote:

Originally posted by GrahamLaming:
Have you tried the Warnqvist test?

No.. But I fail to see what that would tell me.

The only thing I can think of is that if there is a contaminant in the raw oil that is massively throwing off my titration results. Even so, I have done one other test that would make the Warnqvist test a mute point to prove there is a contamination.

Test 1:
Mix 250ml of known good WVO with 250ml of water and shake.
Result = Clear and sharp separation within a few minutes. Cloudy oil on top, cloudy water on bottom.

Test 2:
Mix 250ml of problem WVO with 250ml of water and shake.
Result = about 100ml or so of cloudy oil on top that phases into a yogurt emulsion on bottom that has so far lasted for ~10 days.

The way I see this, there is obviously a problem with the WVO itself and not my process. No matter what the Warnqvist test says about the quality of the reacted product, I have a problem in the WVO to begin with. Do you see this from a different perspective? If so, please let me know. I think I understand the Warnqvist test and what its doing (sort of) and fail to see how it would give me any answers.

Hi Murphy,

Don't do it then.

But if you look at the procedure, doesn't it look like it might help answer your question?

Another test I think might give some useful clues is the reprocess test.

Again, up to you if you do it.

Would I be right in surmising that you are every doctor's worst nightmare?

quote:

Originally posted by GrahamLaming:
Hi Murphy,

Don't do it then.

But if you look at the procedure, doesn't it look like it might help answer your question?

Another test I think might give some useful clues is the reprocess test.

Again, up to you if you do it.

Would I be right in surmising that you are every doctor's worst nightmare?

Graham,
Your insistence on having me do that test is giving me an "I'm a bit stupid" feeling. Obviously you feel that the test would give me some answers that I am not understanding. I thought that test was to determine the conversion quality of the reacted product. Can you please fill me in? Obviously I don't have the understanding of it that I thought I did.

The re-process test is a problem for me as I don't have any NaOH on hand. I keep meaning to visit JoeM to get some but rarely go down his way. I don't want to buy a 50lb bag of it when I'm only going to use a few grams every now and then. As you know, I use KOH. I've done very little research on NaOH sources. Isn't there one drain cleaner or something I can use?

I rarely ever go to the doctor. Its been about 4 years since I was sick enough to do that. However, are you suggesting I am hard headed? I'm not!! I just need an understanding of the how and why of things before I use them for answers.

Thanks for all your help.. Please understand I am not arguing with you by any means. From a processing point of view I've gained a bit of experience. From a troubleshooting point of view I'm still pretty much a newbie since I've had so few problems.

Thanks again for all your help. You have no idea how much I appreciate it.

Hi Murphy,

You've got a strange one here, and I think we're all a bit puzzled by it.

The more evidence we can get together, the clearer will be the picture.

I'm just trying to get as much evidence as we can, so we can have a better chance of solving this puzzle for you.

Here's what you want ...

Good conversion BD which can be cleaned and dried.

Simple.

So, let's first get an idea of how well your BD converted.

The Warnqvist and/or reprocess test will help with that.

Here's how the Warnqvist test helps...
Converted BD will dissolve in methanol.
Non solubles such as oil, monoglycerides and diglycerides will form a residual layer.

When we know how much is left, how much is not BD, we will have a rough idea of how big the problem is.

Now, we are pretty sure that not all your BD is BD, because something in there is causing the wash to emulsify. So, let's see if we can eliminate the most common cause of emulsion, which is mono- and di-glycerides.

How do we do this?

With a reprocess test - just a 1 litre batch would be enough.

1 litre of you problem BD, 1 gram NaOH dissolved in 50ml Methanol. Process at 50C for 1 hour. Let settle for a good many hours, and see if any glycerol settles out.

If you get glycerol settling out, you must have had glycerides in your BD.

Until you do one or both of these tests, you will have 2 pieces of the puzzle missing.

Your symptoms shout out 'incomplete reaction'.
You get emulsion, and you have clear wash water.
This is an easy problem to resolve if it is the case.

You can prove or disprove this by doing the tests.

I hope you only find it is incomplete reaction.

Keep an open mind.

I know you've done everything by the book, but there are so many variables in oil stock, we all get surprised from time to time.

Mostly the answers are simple ones and the problems we think are there, in fact, are not as great as we thought.

Occam's razor springs to mind.

I'm guilty of it, everyone's guilty of it. Sometimes we focus too hard on our strongest belief and it takes focus off the real areas we should look.

We want you to get good BD!

Graham,

Well, I did one of the two tests.. I'll be going to the store to pick up some lye this weekend but I got one test done anyhow.

Here is what I did and the results of the Warnqvist testing:
I should note at this time the following:
1. 75ml jar was cleaned with 90% iso alcohol and then cleaned and throughly dried with both a clean rag and compressed air.
2. I did each of the 4 tests below with samples from the same batch but in 2 different stages of processing. The first run (A) of 4 tests was from reacted, un-washed, un-dried bio. The second run (B) of 4 tests was from bio that had been washed and had 4 hours of settling time but had not been dried.
All results were the same.

***********
EDIT: 7/30/06 @ 10:33AM
Tests B, although was taken from wash tank, was dried on a hot plate at 140 deg and stirred till clear.
***********

Test 1a and 1b:
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.

Test 2a and 2b:
Same as 1.
Results = Same as 1

Test 3a and 3b:
Same as 1 except I used 25ml methanol and 3ml bio.
Results = Same as 1

Test 4a and 4b:
Same as 1 except I used 20ml methanol and 3ml bio.
Results = Same as 1

I should also note that I have done this test before when it was first mentioned in the forum. I performed the test on my very first 1L batch of bio I reacted in a pop bottle and microwave oven to keep it heated. (Yes I still have it sitting in my window sill) The liquid did cloud up and it took about 10 minutes or so for it to clear.. I had 2 or 3 small droplets of drop-out.

A couple other notes..
1. I weigh out 500gram batches of KOH and each sealed batch is usually a few grams over.
2. I always round up my KOH. IE: if my calculations come out to 1260 grams, I usually go with 1300.
3. I always use 22% meth. IE: 40 Liters for a 180 Liter batch size.
4. It takes 25 minutes to inject methoxide and the timer doesn't start until its all in.
5. I always process for a full 2 hours at a steady 130 to 138 degF.
6. My pump is over-sized. 1.5 HP 316 cast stainless.

I have a feeling that I have "surfactants" in my oil.. This may be the result of a contamination of some industrial type of cleaning compound.

And one other update.. I reacted a new 180L batch of known good oil on Thursday and started washing on Friday. It also formed an emulsion but not nearly as severe as the problem oil. This leads me to believe there was residue in either my collection sucker, reactor or wash tank. (mostly the collection sucker as I never cleaned it out)
Anyhow, I dried the batch today.. It took about 20% longer to dry than normal and I had to crank up the heat to 115 degF instead of my normal 105 degF to give it an extra kick. It was clear and dry in 3 hours.

The known problem oil batch is in my second wash tank. I'm letting it settle. I have a feeling its going to be another 3 or 4 days before its ready to be dried..(If ever)

Hi Murphy

It is strange that you had no drop-out, especially with the 'wet' bio in test 4a & 4b.

Let me think on this a bit ...

hmmm
well for starters to much KOH aint going to help you wash and 220ml per batch is a little light for KOH but thats just what my tests have proven to me.
i know that with KOH when you have to much you make water washing a real problem loads of mayo and if there aint enought methanol you just gonna leave the KOH sitting waiting for the wash
ive done this myself on a 15ltr test batch i only added 1 or 2grams extra per ltr and i learned what mayo was from doing this,the bio looked great just cant wash it.

plugly

Hello plugly

You said "220ml per batch is a little light for KOH but thats just what my tests have proven to me."

That is certainly a new concept to me. I think you need to recheck your titration and add a few g KOH for "Good Luck"