Well guys I got one for ya. I recently re calibrated my reactor level gauge with a flow meeter and purchased a new set of 13lb cap digital scales. This showed my gauge had been off by 12ltr and old scales off by 40 grams on 2500g. I had adjusted my base catalyst amount UP to account for these variables and always passed 3/27 test with about 90 minutes mixing time.

My first 300ltr batch after the changes and it failed at 90 min, 120 min, and even at 4 hours still no good. The WVO was from the same tank I'd been using with no problems the past couple batches. The scales are on, methanol tested at 97% on the hydro and the NaOH was same as I had been using. I started with a base of 6g and oil titrated at 2.25 for a total of 8.25 and 22% methanol. This is all the same as the last batch that came out fine.

I removed all the glycerin and then pulled off a couple 1-ltr samples to reprocess.

First Reprocess
1ltr bio
35ml methanol
1.5g NaOH
Results, failed 3/27 with about 40% of the oil dropping out.

Second Reprocess
1ltr bio
50ml methanol
2.5g NaOH
Results, failed 3/27 with about 40% of the oil dropping out.

Both reprocess tests yielded less than 50 ml of new glycerin. Also the 3/27 tests were done with liquids at 68F. Even the reprocessed batches failed as bad as the original batch. So I'm lost as to what's wrong. I'm going to try and reprocess one as virgin oil just to see what happens but any suggestions on this would help.

In the pics below I did a 1/9 ratio in a test tube just for posting. What is strange is the oil seems to be in small beads on the bottom vs all together. I've not noticed this before and found it strange. Also did a shake test on some fuel from the processor, it separated quickly with no emulsion, not as I would expected on under processed fuel. Last I did another titration on the processed fuel, but as expected it took less than .25 ml solution to change, so it looks to be below virgin oil on ffa.

Any ideas on whats up here?

-Ken

Ken

-Ive had 3/27 that looked like that, little pinpiont drops that won't combine, your just on the cusp of passing. you said 40% dropout? that would indicate to me that the base reaction has a long way to go yet. the fact that you didn't have this problem prior to changing two parts of your regular process, would tell me you should relook at that part. somehow there has been a miscalculation here. Just my thoughts Tom

How are you measuring your oil and methanol? Have you checked these against a know measure?

Has you catalyst had a chance to react with CO2 or water in the air?

The oil from the same tank, is it nearer the bottom of the tank? Have you tested it for water?

Thanks Tom I'll try it agian at 3g lye and see what happens. Maybe let the test batch go for an hour, but its on a hotplate spinning at max so typically can pass in 20 minutes.

Andrew, I measure the oil in the reactor with a site gauge that was just calibrated with a digital flow meeter. Methanol tank has molded gauge on in it. If anything I went heavy on the methanol cause I was used to doing 315L batch, but not more than 24%. On the NaOH, that's questionable. It's kept sealed and no issues with it before, if anything I may not have gotten the lye mixed good enough before pulling it into the reactor. Pretty big flakes and takes a long time to blend. I have some Roto brand setting round that I could test a batch with using equal amounts to rule out the lye.

On the water, never tested but was settled for several month before being moved to a 300 gallon inside tote. Previous 2 batch with same oil, no issues.

-Ken

quote:

I measure the oil in the reactor with a site gauge that was just calibrated with a digital flow meeter. Methanol tank has molded gauge on in it.

I would suggest that you verify these measures with an outside, known measure. Gauges and meters can be wrong.

The possibility exists that the oil you ran is wet and or the catalyst is carbonized. Both can be checked.

Start by picking your favored suspect as the cause and work down the list, testing each variable. Good luck!

Ok after taking off a few days to go hang out with our neighbors to north of the lakes and watch some Red Bull air races, I came back and started hitting this issue again. Processed 2 more 1L test batches using 4g lye / 40ml methanol and 5g lye / 60ml methanol. Ran both for an hour on a hot plate stirrer, same results as before Failure with about 40% oil fall out...

Even switch to use some Roto lye I had on the shelf. No difference in the results between the types of lye used.

Checking centrifuged tube samples from each re process batch, I did log increasing glycerin fall out amounts on each. So this points me to believe the original batch had some water in it that slowed the reaction.

Since I was eager to move on, I reprocessed the 275L batch with 5.5 grams lye and 60 ml methanol per Ltr of oil as a last attempt to finish this up. When I was done I noticed the amount of glycerin fall out was much less than expected. Checking my methoxide mixing tank, I found the problem.

The lye I use now days is large flakes and take about 3 times longer to dissolve than fine pellets types. Seems my stirrer rod is not lifting the flakes up off the bottom of the tank and there was a cake of lye that never got mixed into the methanol. This would have been enough to throw off the whole process for starters, and the reprocess. So this batch is going down as total failure, some modifications to the meth mixer are under way and a fresh start tomorrow with a different batch of oil.

Cheers,

-Ken

quote:

little pinpiont drops that won't combine, your just on the cusp of passing. you said 40% dropout? that would indicate to me that the base reaction has a long way to go yet.

Tom and Andrew, thanks again for your input and I wanted to post this little follow up so anyone reading this later on will know what I learned about failing 3/27 tests.

I modified my air powered stirrer in the methoxide mixing container so it reaches the bottom of the tank. This fixed the issue with some lye not getting stirred up and forming small clumps on the bottom. Got ready to run another 300ltr batch but opted to do a 1-ltr test run first using the same titrated oil, methanol, lye as was going in the large batch. I even cranked up the oil sample to 260F to see if any water boiling showed up. All looked good.

Low and behold the 3/27 test FAILED again. Same thing, like 40% BD fall out in little beads.. Man I was stumped, never had this type issue in the past and I though the oil was contaminated.



Then I decided to perform the 3/27 test with some NEW methanol out of the 55 gallon drum I just purchased. The test sample passed the test with this methanol... So didn't the samples from above...

Seems I had left the cork out of my methanol "wine" bottle on the bench a while back and it collected moisture out of the air. Even though the hydro said 97%, this 3% water was enough to blow the 3/27 results. I processed 2, 300ltr batches back to back, both passed the test at 30 minutes mixing time, even though I run at least an hour.

So the lesson here is. When in doubt, throw it out... I learned that a while back with titration solutions, and now with methanol.



-Ken