My first KOH acid base test batch is about to make me cry.....

I've got 30 gallons of oil, dried in centrifuge (pan tested - it is VERY dry)

I put 200ml of ROOTO (93% H2SO4) into 3.5 gallons of Meth - that's about 1.5 ml per liter acid and 10% meth.


The oil titrated at about 11 before the acid was added (at least the batch before it did, and it's the same oil)

I mixed it up for about 3 hours and let it sit 24 hours and it titrated at about 6.5. I added another 50 ml EDIT: acid (not oil) and mixed for 2 hours. Then it titrated at 4.5. I figured that's good enough.

It was a milky brown color after the acid was added, whereas it started out a clear brown. Is this milkyness normal?

I took 500ml of the 4.5 titrated oil and acid/meth and added 50ml of Methoxide (KOH at 4.5 +5 = 9g per liter) and added it to the oil which was at about 120F.

Mixed vigourously and let sit for 10 minutes then mixed again, 3 times in all. Now it looks like this - see pic. There was some glycerin settling out, but it's not returned after the last agitation.

I'm wondering if the water in the ROOTO is the problem and it's made soap? Or maybe I had a little bit of soap left in the appleseed after the last batch that is messing things up?

Or maybe I haven't put enough methoxide in, or perhaps I didn't leave the acid in long enough to let it completely react and now it's messing things up?

HEEEELP! I made a massive batch of soap last weekend, and now this.. At least I didn't do the whole 30 gallons! Yippeeee!

the base for KOH is 8 not 5..5 is for NaOH.

just mix the difference in 1 gallon of methanol and mix in with the rest.

you have a major under reacted batch.

-dkenny

AHA, that would sort of explain it a bit...

So it's 8 g/l of KOH as the base, then add the titration.

So, for this batch

120 l oil

4.5 titration x 120 l = 540 g KOH

plus

8 g/l x 120 l = 960g

= 960 + 540 = 1500 g of KOH to add to the methanol. I'm only 300g off - I put 1200g in. Is the reaction that sensitive? I'm guessing yes.

I put that jar of stuff in a water bath at 120F and this morning it has separated to dark brown at the bottom, then that murky milky brown in the picture above, and on the top is a light brown milky stuff.

Does that confirm the under reacted diagnosis? I was following the Girl Mark post, maybe I didn't see it was for NaOH

300g low is around 20% so if a big difference.

try another sample using correct amount. then you'll be able to see the difference

-dkenny

Dkenny,

Where do you get 8g/l of KOH from? Everywhere I've looked it's 5g/l.

I titrated the remaining oil, and it is down to 3ml. YAHH! Acid esterfication works!

Hello to every body, Im new to all this, and having lots of trouble with it and I see there is doubt about if its 5g/l or 8g/l of KOH, Im using 5g/l and its not going so good.

its been that for a long time.

5g/l NaOH = 7gKOH but adjust for purity
7/0.9 = 7.77 rounded up to 8.

sites like JTF still have it wrong with the old values of 3.5g/L NaOH which would 4.9g KOH

-dkenny

I did another test batch, now that the acid treated oil has had a chance to sit for a few days.

It titrated at 3ml, so that's great - all the way from 11. It is 120l (30 gal) and I put in total 250ml H2S04.

For this test batch I did

50ml KOH at 9g/l (I had already mixed this up so I just used it).

500ml oil.

After 30 minutes it has separated well. But the BD is still quite dark. Is that because the acid burnt the oil, or maybe it is not completely converted. How to check?

I just did a 24/7 test on the BD - it is under reacted (good call DKenny).

I've put another 10ml of methoxide in it and shook it up and in a water bath at 120F to see how it goes.

I always use 7g/L as my base and I use KOH exclusively. I thought you didn't have to adjust for purity if your stock titration solution was made with same KOH that use a catalyst? Or is it just the titrated amount that doesn't need to be adjusted?

its the titrated amount that doesn't need adjusting. the base needs. it also depends on how good is you oil?