quote:

Originally posted by girl mark:
For the purposes of comparison for this thread, could we (americans anyway) maybe all start doing this test using Heet brand methanol (auto parts store dry-gas) just to make sure everyone's using the same chemical and to take storage/water absorption/whatever factors out of the methanol side of the picture more or less?

Mark

Just this morning I stopped at a new O'Reilly auto parts store and picked up a couple of bottles of "HEET" in the yellow bottle. I just finished testing the specific gravity of this HEET brand methanol.

The specific gravity tested at 0.794 gm/cc. This compares exactly to the specific gravity of the methanol used in the testing reported above. I also retested my methanol today and the SG, like before, was 0.794 gm/cc.

The testing was performed on a Mettler/Toledo model KEM DA-100M Density/Specific Gravity Meter. The meter was last calibrated on 7/5/06 and is recalibrated monthly (I previously said bi-yearly).

I have tested the SG of recovered methanol on several occasions with this same instrument and some of the "first flushes" from the condenser have tested as low as 0.792 SG.

Hi Tilly,

Just got in to check the forum, with regards to the CG test, I will need to ask my friend on how it was tested.

AFH

Hi to you all
Dear High Compression II

According to my caculations.
If your measurement was exact,
then it should be 0.66 ml
instead of the 0.75 ml.

Please forgive if I am wrong.

aiad7

Q. on using the results for reprocessing

Hypothetical question...

I get 0.5ml of oil dropout from a 3ml washed, dried sample, in 27ml Methanol.

This is a droput of 16.5%

Would this mean that in a 100 litre batch I would have 16.5 litres unconverted oil (mixture TD,DG,MG)?

Would I then reprocess my batch with quantities of methanol and NaOH according the remaining unconverted volume?

In other words, reprocess with 5g NaoH x 16.5 = 82.5g NaOH ...

22% of 16.5litres of methanol? = 3.6 litres Methanol.

Would it also be sensible to draw off this droput and titrate to adjust NaOH qty. ?

Or use the starting stock titration as a guide?

Perhaps we can find a rule of thumb to replace the 5g/litre & 22% /litre meth, to be more appropriate to reprocessing the remaining unconverted oil.

I guess the TG|DG|MG ratios will be markedly different, compared to the starting stock.

ive done a few 1 ltr tests now using Jans method
here is what i have found
titration of waste oil was 2+ base

sodium base set to 5g: 200ml methanol
potassium set to 7g: 200ml methanol

sodium gave oil
potassium gave oil

so i did another set of tests

sodium base set at 6g: 200ml methanol
potassium base set at 8g: 200ml methanol

sodiumm was 100% good no drop out at all of oil
potassium was cloudy but no drop out of oil

a little unsure of why the potassium was cloudy i did another 1ltr test and it was cloudy again

so i did a potassium test with 250ml of methanol
and it was 100% clear no drop out of oil.

plugly

Hello Pluggy, excellent information

That sounds very promising.
If I remember correctly, Neutral's test that showed the biodiesel just scraped into ASTM conversion with 5g NaOH for new oil was actually using 220ml methanol, not 200 as most of us use.
Also, neutral alway said he thought there should be a further adjustment to the NaOH for the extra water produced as the FFA content increased.

What was the purity of the KOH?

the KOH im not sure of the % i believe it to be 90%
im sure if u have a cloudy 1ltr test add 50ml to it and shake it should clear on the next Jan test
plus if you get a fail on oil depending on how much you get e.g the droplet the size 3mm just add 50ml with 1g it should make the test pass

btw Tilly all the things you have done have helped me with finding answers to this test with out them i would have been stuck.
Keep up the great work

plugly

Hello Plugy

Yes, if you are trying to make high conversion biodiesel, my tests have shown that if it does not pass the "test" the first time, it always passes the "test" if you re-process with 1g NaOH in 50 ml methanol.

KOH often comes in the 90% purity flavour. Check to make sure.

Hi Tilly,

The GC test was accordingly capilary GC test, if this makes sense to you.

Should there be any specifics in a GC test that I might need to know more about?

Regards,
AFH

Hello AFH

Thank you for that information. I do not know much about GC tests.

Plugly, good information indeed. You've seen how changing two variables affects the apparent conversion. However...

Has anyone done tests to see the effects of changing time of processing, without changing the chemical recipe? I.e., if 20% methanol and 7.7g/l of 90% KOH plus titration is a recipe to rely on, but doesn't come up with good conversion, is it possible that simply leaving the processor running for an additional half hour would be successful?

quote:

Originally posted by plugly:
ive done a few 1 ltr tests now using Jans method
here is what i have found
titration of waste oil was 2+ base

sodium base set to 5g: 200ml methanol
potassium set to 7g: 200ml methanol

sodium gave oil
potassium gave oil

so i did another set of tests

sodium base set at 6g: 200ml methanol
potassium base set at 8g: 200ml methanol

sodiumm was 100% good no drop out at all of oil
potassium was cloudy but no drop out of oil

a little unsure of why the potassium was cloudy i did another 1ltr test and it was cloudy again

so i did a potassium test with 250ml of methanol
and it was 100% clear no drop out of oil.

plugly

Hello George,

Yes, that has been done. It depends on the temperature.

quote:

Originally posted by Tilly:
Hello George,

Yes, that has been done. It depends on the temperature.

Well, I knew that temperature represented yet another variable, but I gathered that without a pressurized reaction vessel, you were somewhat limited on temperature because of methanol boiling.

Anyway, if it has been done, what were the results? And at what temperature?

Hello George

Neutral did some tests with GC and I did some with viscosity.

The "Rule" I use is 1 hour at 50deg C,
I think it was actually around 50 minutes, I'll see if I can find the tests.

quote:

Originally posted by Tilly:
Hello George

Neutral did some tests with GC and I did some with viscosity.

The "Rule" I use is 1 hour at 50deg C,
I think it was actually around 50 minutes, I'll see if I can find the tests.

Sorry to be a pest, but this isn't exactly what I'm asking. My question revolves around Pugly's changing of variables (catalyst and methanol) and their effects on conversion completeness.

Picture this scenario: suppose you use the Warnqvist test, find that you haven't achieved a complete reaction with 20% methanol and the "proper" amount of catalyst. Could you then simply turn the reactor pump back on for some length of time and get the same results that you would have had you added more reactants?

Suppose further that we found you could completely react the oil by adding x% more methanol and n grams more catalyst, then reacting for 30 minutes. Could you, again, have achieved the same results merely by reacting the oil for 60-90 minutes longer, not having added any more reactants?

I think any answer would be an educated guess, the only way to find out for sure would be to try it.

from what ive seen time dont really effect the out come when the jan test failed it didnt matter if it had sat for a day or an hour it failed only when i changed the amount of chemicals have the results changed heating and other elements have not mattered but if anyone thinks they do please do the tests and post your results would be good to get other test results to view and compare

plugly

Hello George

No, tests show that at 50deg C, the reaction is finished in about an hour with refrence to the amount of chemicals being used.
If the NaOH were not being consumed in a side reaction what you say would be true.
This assumes you mix properly. Further mixing makes no improvement.

quote:

Originally posted by Tilly:
Hello George

No, tests show that at 50deg C, the reaction is finished in about an hour with refrence to the amount of chemicals being used.
If the NaOH were not being consumed in a side reaction what you say would be true.
This assumes you mix properly. Further mixing makes no improvement.

Got it. That makes sense...thanks!

Did a 'Time-Test' on my last batch.....

I do a 'equal-half' meth, Two-Base reaction.

(My NaOH for each half is different....
1 St Base- 6.5 grams, Plus titration, X 1.2 Divided by 3, then times by 2. This NaOH then mixed in 13% meth approx.

Second-base, after draining glyc from first-base, is a straight 5 grams NaOH in 13% approx meth.....)

After the first base, the fuel failed the test dismally...--No real surprise there!

After 10 mins into the second base, near clarity was the result..

At 15 mins, perfect clarity of the meth-test resulted.

The reaction is at 62 degrees C, 1600-1800 litres, pump mixed. My normal reaction time is around three-quarters hour for both bases. The test shows I can 'trim' the time of second base to around 15 mins, plus 5 mins for 'luck...'

Great test, I love it!