I have some wvo needing to be processed that is titrating around 50! I was out of pH indicator so I am using turmeric for the first time until my normal stuff arrives. I will double check it at that time, but it is definitely some nasty stuff.
So far I have gotten the titration down to 30 in a minibatch via acid pretreatment. The first treatment was 2ml/L H2SO4 (93% pure) + 120 ml/L methanol. That took it down to about 40 koh before it stopped dropping, so I hit it again with 2 ml/L H2S04 + 40 ml/L methanol. That got it down to 30 koh and stopped, so I hit it again with the same treatment (2 ml acid/40 ml methanol) but did not have any effect. Mixing at 130F, pretty dry oil (1% water)
What do I do next? I have never drained any water off or anything. I'm hoping to find the right amount of acid/methanol so that I only have to treat it once and of course using hopefully less methanol when I do the big batches.
I think it was dkenny that had a formula to use but with this high of ffa the formula recommends something like 10 ml acid/L oil! I'll do it if it will work but sounds scary.

any ideas?

dogg4585

Have you tried mixing at least 10 10% glycerin by product? I heard it also lowers the FFA?

rasza

Is this done before the acid stage?

If so, it would be glycerine 100ml/L oil, mix/heat and titrate before doing either acid or base reaction, correct? Do you drain the glycerine or go ahead with the reaction?

dogg4585,
I haven't tried using acid, but I do seem to recall that you have to drain of the water that forms before moving on to the next stage. Don't take my word for this, please look through the other threads first.
regards
dva

dogg4585. We work with high acid oils set esterification with glycerine, and also have used the heat with methanol version. My recommendations, first, heat oil to at least 250 F to remove water. Second, you formula is ok but you should heat to around 145 or just below the boiling point of methanol after adding the methanol/acid solution. When the titration stablizes, boil off the methanol which will have some water in it. Let cool and separate the liquids. The top is usually oil and the bottom residual materials including water and acid. Use only the top layer and repeat. Try to get to below 3 before stopping this and going to base method, after methanol removal and separation. The methanol will have water in it and unless you can distill it off discard.

cat123-

what amount of methanol/acid should I use for each step? Example titration 50. Also, how long does it take for the acid/methanol layer to settle before draining?

thanks

Dogg4585,

Ive been experimenting with glycerine to lower FFA's and would be interested for you to perform the following test on you #50 oil.

240 mL oil in a jar
add 240mL crude glycerin to oil, agitate
perform titration in 30 minute intervals

Here is my original threadhttp://biodiesel.infopop.cc/eve/forums/a/tpc/f/719605551/m/6831000712

jon

I will try your experiment as soon as i can.

dogg4585,
what happended?

rasza tried my method with some worse oil and got good results. I'll let him post them.


-dkenny