Hello,

I made from 34 gallons of used Soy Oil, 22 gallons of bio with KOH which I had to reprocess a second time to get it to pass 27/3 (1 ml/1 gram for reprocessing.) No water wash, demethed the bio by itself, bubble dried down to .1% methanol (measured with a breathalyzer) and let settle for 2 weeks. Drained remaining glycerin, then ran it through 10 gallons (by volume) of hardwood wood chips (supplied by a furniture and milling place so wood type unknown but definitely hardwood) for 4 hours (probably 3 cycles) and then 4 hours through a Thermax resin column (4 inch wide, 24 inch deep of resin - column is 4 feet high)

Got all that?

OK, I haven't measured the soap content yet as I need to get some HCL but will today and post numbers later. However, on a shake'em test, the bio after the wood chips came out clear with perhaps the slightest (and I mean barely visible) haze in the water. The bio that came out of the Thermax resin column, after a shake'em test, the water was crystal clear and the bio was also crystal clear after separation and just a few minutes in the sun. I was happy!!

However, did a pHlip test (little red bottle enzyme test) and its results showed I had excess catalyst. (The top bio layer was cloudy.)

Any thoughts?

Here are some assumptions that are implied with dry washing which might not be totally correct. The other option is I totally screwed up like using a syringe that had had catalyst in it in the past.

1. All (most) excess catalyst will fall into the glycerin and not remain in the bio.
2. All (most) remaining catalyst will be converted into soap.
3. Flip test are accurate for dry washed biodiesel.
4. Wood chips remove soap as opposed to break apart Catalyst+Glycerin (which is soap)
5. Anything else?


I will attempt a 5% post wash and run a flip test on that and see if my catalyst problem disappears. My hunch is that if your using KOH, you will need a 5% prewash on bio to make the wood chip and/or resin tower make ATSM (well close) level fuel.

I guess my question is, has anybody run a good test ATSM, CG, Enzyme, or pHLIP on KOH made biodiesel
that has only been run through a dry wash?

Thanks
Doug

This message has been edited. Last edited by: Doug Weiner,

Doug,

quote:

I made from 34 gallons of used Soy Oil, 22 gallons of bio

That is lousy conversion. I think you need to figure out why you had such bad conversion then try to troubleshoot the rest of your process. What was the titration of the oil?

I have never heard of Flip tests. Are you sure it's not pHlip tests?

you are right pHilip.

What should the conversion rate should be?

Doug,

I would be very disappointed if I had a conversion rate below 90% with oil that titrated at 4 NaOH or lower. I normally expect 32 gallons BD out of 34 gallons of oil.

If I do the AE process prior to base transesterification, it will be near 100%. If I do the 80/20 90/10 2 stage base process, I expect 100%. You need to figure out what is going wrong with the conversion and then proceed to the drywash.

I can't help you with the pHlip test, as I have never used it. I test for soap occasionally, but it is to make sure that I am not slipping up in my gut hunches. I haven't been proven wrong yet on my gut hunches.

I think Jon Heron from Canuckland does the pHlip test. Maybe he will chime in.

Hi Doug,
I have done phlip tests on push/pull and WBD batches with great success, no signs of excess caustic, glycerides or acid in either one. However I use NaOH instead of KOH if that makes a difference?
Have you looked at THIS detailed PDF of the the phlip results? A slight haze is normal for on spec fuel, with excess caustic the test will be opaque and look like crap, see attached photo from the PDF.
Good luck!
Jon

Oops, the pic didn't work its too large but look in the pdf and it shows what caustic contaminated bio looks like in the test specifically...
Jon

Eurocab,

I am confused about your numbers. Where does all the glycerol go in either process? I was under the impression that you see about an 80% return from wvo to bio. If I am mistaken, please point me to threads about this.

Doug

Jon,

You might be right about the haze. However, when I water washed last time, I got near mirror finish and clear bio on top. I think I misread the little piece of paper in my kit about excess aklaine and see more clearly in the power point presentation. My PH is good as the purple color didn't change. So basically, no extra catalyst. However, my Bio is turbid which perhaps means some soap. I will have to get the HCL soon.

I think the interesting point is that the shake'em test indicates "no soap" when in fact there is some according to the pHlip test.

Thanks
Doug

quote:

I was under the impression that you see about an 80% return from wvo to bio. If I am mistaken, please point me to threads about this.

The yield from wvo depends mainly on how much soap is made. Any soap that is made represents lost fatty acid chains. So, with low titrating or new oil, yields can get close to 100%. Also, soap takes bio with it into the byproduct layer and out with the wash, if you use water.

Some claim over 100%, but that gets kind of hard to explain with balanced equations from what I have seen. Not saying it can't be. Just hard to explain.

I have seen 90-95% over time on low titrating oil, and I have a heavy hand with the catalyst.

HTH.

Andrew,

What size batches are you doing?

Lets take a 130 Liter batch (34 US gallons) done in a simple appleseed processor. At 5% you would only drain off 6.5 liters or 1.6 gallons of glycerin? I am amazed. Please others chime in as I find this hard to believe but if I am wrong please point the way.

Doug

quote:

What size batches are you doing?

Lets take a 130 Liter batch (34 US gallons) done in a simple appleseed processor. At 5% you would only drain off 6.5 liters or 1.6 gallons of glycerin?

Let me clarify:

If I start with 140 L, using 18% ME (25.2 L) I drain off about 27-30 L of byproduct. In my view, it is important to call it byproduct, since it is made up of several things, including glycerin, soap, ME, catalyst and BD. The raw, unwashed amount of BD is a bit over 135L, but keep in mind this includes some ME and some soap. Often end up with 130L +/- 2 or 3 of clean, dry fuel, as long as I am patient and wash gently. So, if I get 127L that is about 91% yield.

To further explain, in the reaction, three ME molecules replace a single glycerin backbone in a transesterification reaction. This creates 3 FAME molecules for each triglyceride of starting feedstock. So, the volume of the FAME is similar to the volume of the Triglyceride, unless there is excess soap production.

HTH.

Thanks for the good explanation. I need to re-measure the amount of oil I am putting in. That must be off to have such a large discrepancy.

I mean, if I pass 27/3, there is really nothing left to transesterfy right? So when you are done you have

Bio
Glycerol
Soap
unreacted Methanol
unused catalyst (must be close to negligible for volume.)


By my numbers,

I am putting in 34 US gallons of WVO.
7 US gallons of methanol for a total of 41 US gallons.
Drain off 8 US gallons of Glycerol.
Leaving me with 33 gallons of Bio with meth.
Boiled off the meth and I need to measure that, but lets call it 2 gallons for now, leaving me with 31 gallons of Bio plus soap.

When I measure my clear 55 gallon drum where my cleaned Bio now resides, I calculate that I produced 20.5 gallons. - according to my cubic calculator 12.5 inches in my 22 inch wide 55 gallon barrel = 4165 cu3 inches which is 20.05 US gallons).
For good measure lets say in the resin column there is still another 2.61 gallons.
Lets also say another gallon left over in the wood chips and pumps.
Lets put in another gallon in spillage.

That means I should have produced 26.5 US gallons and I am seeing 20.05. Thats a difference of 6.45 gallons. Is it really possible to produce that much soap!!! I have to think something is off with my numbers.

Doug,

Your method of measurement may be accurate -- I am not sure. To determine volume in a 55 gallon drum, I measure from the insede bottom of the drum up to the bottom of the lid and divide that into 55 gallons to get how much volume per inch of liquid.

As Andrew has pointed out, your volume can be greatly reduced by the amount of soap produced. Soap can be formed by processing wet oil, high titrating oil or using too much catalyst.

One mistake I have made in the past was adding too much catalyst. I processed the oil and did a 3/27 which showed poor conversion. I then tried to reprocess and lost a lot of product to soap. My initial mistake wasn't in having too much catalyst, but in mixing. I use two pumps to mix, but unknown to me at the time, one was turned off, so I added more catalyst.

Your numbers still sound amazingly low. On your next batch you might want to double check everything.