I need some help. Recently my oil went from an average titration of 7 to 15-20. I started using an acid pre treatment where you subtract your starting titration from your desired titration and then multiply by . 2 to get the amount of acid needed.
My first batch started at 15 and stopped dropping at around 7. The second batch started at 18 and ended at 7 despite using 2 more ml per liter trying to get the titration to drop below 7.
Now my third batch started at 10 and I decided to go back to the original recipe to see if that would work with a lower starting titration. It didn't. After 12-15 hours of heat and circulation the oil still titrates at 8.
My acid is 93% pure. The oil is dry.
What am I missing?

Thanks,
Greg

for the first 2 batches, you're seeing something I've noticed before. adding more methanol and acid I was able to push the process further, but I recently I've been experimenting with draining. it turns out that your first 2 batches fall right the range I've been experimenting with. the results are good. just let them settle for 10-12 hours then drain out about 1/2 of the methanol quantity you started with. remix then check the titration again. I suspect you'll find the titration drops to around 3.

your 3rd batch is puzzling... are you using 12% methanol base on oil volume? are you checking the titration while the stuff is mixed? in this batch you used 1.4ml or acid per liter right?

-dkenny

quote:

Originally posted by dkenny:

your 3rd batch is puzzling... are you using 12% methanol base on oil volume? Yes are you checking the titration while the stuff is mixed? Yesin this batch you used 1.4ml or acid per liter right? Yes

-dkenny

I did let one batch settle and then drained off around 4 gallons. This yielded a lower titration than I had the day before but still not close to 3.
I have read that people are able to titrate it every hour after adding the acid and "watch" the titration fall. I have never been able to do that.

Did you figure out the problem with acid esterfication?

No. Any ideas?

Gbrown,

how dry is dry? for acid processing the drier the better. generally 0.1% less..this is just a guess.

but if you're getting 4 for 18...that's still a great improvement...just run the base stage at that point..if you've gone from 18 to 25...wait a minute..something major is wrong.

what temp are you processing at???
I like 140-150F..


-dkenny

The only way I know to test for water is to heat a small amount to 250 and see how much it boils. By that method the oil has been very dry.
The best results so far have come from processing, settling, then draining off around 4 gallons then titrating. This has still only resulted in a titration of around half of the starting number.
So far I have never got it to fall below 7 but I have always had good conversion.
I have been processing at 130F. I'll try raising the temp and see if that helps.

Thanks for the input, keep it coming.
Greg

one more thought...
are you using the same methoxide tank for both acid and base???if so stop..get a 2nd one just for acid...unless you can completely get the base residue out it'll neutralize some the acid you need.


-dkenny

Great point!
Yes, I'm using the same tank.
I'll get a second tank set up right away.

Thanks,
Greg