Titration - I bought a 1 liter bottle of aquafina... I assume that this is an accurate enough measure of 1 liter for the water/lye solution?

When I did the blank titration, I had some confusion about the colors. First, it never turned any shade of yellow - it was 100% as clear as water. Then when I was adding the phenol, I wasn't sure if I should stop at a slight purple or keep looking for the deeper purple that came with more phenol.

Ultimately, I didn't get a consistent result from one titration to another so I continued with the base amount of KOH (7.5g of 93% pure). I figured this should be right since I used fresh vegetable oil.

I washed it tonight and managed to end up with the picture below. I switched to using a mason jar on the 4th or 5th wash because the dr pepper bottle was collapsing and getting to be a pain.

So my three questions are...

1. Titration - did I do something wrong for it to not turn yellow? Should I get some oil samples of various levels of nastiness to practice titration?

2. Can I get a "check-mark" on the fresh oil practice and try making some 80 liter batches or do I need to do the dr pepper batch a few more times? I should note that I haven't acquired the first part for an 80 liter processor yet so a large batch isn't going to happen tomorrow.

3. Are there any other tests I can do besides the "clear water after washing" test?

wash6.jpg (43 Kb, 46 downloads) Final wash

To answer your questions:
No, a one liter bottle of Aquafina is not only inaccurate, there are other things in the water as well. Use distilled water, one liter and one gram of NaOH (or KOH) measured to a minimum of 0.01grams. An accurate titration solution is critical to good results because a tiny error here is multiplied in bigger batches. Also, phenol red is not the preferred indicator. It indicates at a pH higher than what we want. It works, but not well. Phenolphthalein is the preferred indicator. Turmeric is a close second. To blank your solution, add the 4 (or so) drops of indicator to the IPA, then one or two drops of the titrating solution should bring about the color change. THEN you add the oil. Careful measurement of one mL of oil is critical too.

2 Depends, do you feel confident to make an 80 liter batch? Go for it, if you mess it up, it will be a valuable learning experience. After all, we learn more from our mistakes than our successes.

3: The 3/27 test will give you a good indication of you conversion. It is well explained on this forum. Also called the Warnqvist test. HTH

quote:

Originally posted by wupulamp:

1. Titration - did I do something wrong for it to not turn yellow? Should I get some oil samples of various levels of nastiness to practice titration?

2. Can I get a "check-mark" on the fresh oil practice and try making some 80 liter batches or do I need to do the dr pepper batch a few more times? I should note that I haven't acquired the first part for an 80 liter processor yet so a large batch isn't going to happen tomorrow.

3. Are there any other tests I can do besides the "clear water after washing" test?

1) Check out these Video's on Titration.

2) Make some more Dr Pepper Batches.

3) You can find a full list of Homebrew Tests here

quote:

Originally posted by Joe_M:
phenol red is not the preferred indicator. It indicates at a pH higher than what we want. It works, but not well. Phenolphthalein is the preferred indicator.

Actually, I used Phenolphthalein 1% from NebraskaBioPro.com. Are the directions here ( http://www.biodieselcommunity.org/titratingoil/ ) not accurate for Phenolphthalein?

RickDaTech - I tried looking at those videos - can't play WMVs on my Mac - I'll look for a converter or something tomorrow. Thanks for the link though.

Phenolphthalein is good and so are the instructions. You may or may not get a yellow color depending on the oil you use. You add the titrating solution until it changes color and the color change is persistant for 15 - 30 seconds. A light pink is good if it stays light pink for at least 15 seconds.

Not to speak for Joe, but I think he was trying to indicate that when mixing your titrating solution, accuracy is very important. If you get the titrating solution off by a little, it can throw your titration off by a lot.

The yellow I was looking for was with just 10ml of ISO and a few drops of phenol (on the blank titration). I used ISO Heet and kept adding phenol (I think I got up to 25 drops on the first try) but never got a yellow color.

I'm going to check with the pharmacy today about some ISO so I don't have to use the ISO Heet - maybe that will make a difference.

Wupulamp,
Sorry, in your first post you used the word 'phenol'. That usually means phenol red, now I see you were using it as a short term for phenolphthalein. You know that old saying about what you get when you assume.
Rick is correct, very careful and accurate preparation of the titrating solution is critical. As for the yellow, phenolphthalein does not turn yellow. It is colorless in acidic solutions and turns pink in basic. You don't keep adding drops of the indicator, you add drops of the titrating solution (lye water) until it turns pink. A few drops of the phenolphthalein in the 10 mL of IPA is all you need. Drug store IPA is usually 70 or 90%. Occasionaly you can find 99. That is what I use. Gas line antifreeze (such as IsoHEET) are 99% as well, the only problem is sometimes it can be acidic and takes more titrating solution to neutralize it. That's why the blanking is important. It assures you are not getting a higher reading from your oil due to acidic IPA. HTH

Breaker, breaker!
I followed the link from Rick for the tests. Whew! Should I perform ALL those tests? So far I've made a 1 liter batch and it turned out kind of cloudy. Did the 27/3 test and the meth stayed cloudy for hours but finally cleared up with just a bit of oil (maybe 5 drops) in the bottom. I heated the BD (poped and fizzed for a while) and plan on titrating it as before to see what happens.
What tests would you consider "crucial". I want to get some of this in my truck but am hesitant--don't want to hurt anything. I will be mixing with regular diesel so maybe the purity doesn't have to be paramount?
Also what temp do you heat the oil to before titrating? How about before mixing?
Thanks to all.
John