Hi Everyone,

I’m new to the forums. This is only my second one liter batch I’ve made. The WVO I can get titrates out to 10+. So it looks like I have to use H2SO4 to bring it down.

Now from what I understand this is the process, of which I have followed.

1L dry oil till al the water is out.
Add 100ML methanol per liter
1ML 95% H2SO4 per liter but no more than 2ml
heat to oil to 120F
Started mixing the oil then I added the methanol to the oil.
After the oil turned a creamy mocha color and waited for about 5 min. I added my 1.5ml of H2SO4.
The oil then turned a very dark brown

So what I did prior to this is I titrated the oil. That number came out to 5. Using NaOH 95% pure and a base of 5

So from what I understand using 95% pure NaOH, it should be 5 /.95=5.26. So I round up to 5.5 for the base. Total 5+5.5=10.5

To get my acid amount I took the total titration of 10.5-3=7.5. Took 7.5 *.2 =1.5

Mixed all this together for two hours. Let cool and took another titration and it ended up being 1.5. Is that right?

So from what I read after you mix all this stuff together, you are suppose to let it set over night for the best results. I took another titration and it was still 1.5.

But my main question is, the next day you are suppose to drain all the water that forms from this process. However there is no water. Why is that?

I've heated to remove the water and the oil is very dark brown, almost black...but no water.

--Tony

Use your glycerol from previous biodiesel production rather than acid esterification. Simpler and safer. Just mix, stir and let the glycerol settle out. The oil you get will be cleaner than you would if you didn't glycerol treat. My recommendation is only acid treat if it is a large volume and over 20. Otherwise blend with good oil or glycerol treat. Take the simple and safe step.

Tony,
from what you wrote you added the methanol to the oil without the acid.. normally the acid is mixed with the methanol then added to the oil.

2ml of acid is not the upper limit. the upper limit is determined by the titration. I used 4 mls of acid per liter.

don't adjust the titration for purity..it self adjusts. For example, if you used pure NaOH for titration and got 2. for the same sample using 50% pure NaOH for titration you'd get 4.

2hrs might not be enough mixing time.

quote:

To get my acid amount I took the total titration of 10.5-3=7.5. Took 7.5 *.2 =1.5

this should be done first. it determines the amount of acid to add to the methanol.

the amount of water depends on the titration. for a starting titration of 10 you might not get enough water to measure. also the water is mixed into the layer at the bottom and will look gylcerin. but its a mix of water, methanol and acid.

if you're doing titration in the middle of the batch make sure the batch is mixed..

using the acid/base process results in a higher yield than using Glycerin to lower the titration. Glycerin and caustic stripping methods create soap from the FFA instead of fuel. but they are safer the using H2SO4.

-dkenny

quote:

Originally posted by funnyfidel:
Use your glycerol from previous biodiesel production rather than acid esterification. Simpler and safer. Just mix, stir and let the glycerol settle out. The oil you get will be cleaner than you would if you didn't glycerol treat. My recommendation is only acid treat if it is a large volume and over 20. Otherwise blend with good oil or glycerol treat. Take the simple and safe step.

Hi Funnyfidel -- Thanks for the information, I'll try that next time.

--Tony

Hi dkenny,

Thanks for the reply.

quote:

the amount of water depends on the titration. for a starting titration of 10 you might not get enough water to measure. also the water is mixed into the layer at the bottom and will look gylcerin. but its a mix of water, methanol and acid.

The interesting thing is that I do not get a separation of the mixture you talk about. After about 2 hours, I retitrate the oil to see if it has dropped, if not I continue mixing. If it has, I let the oil sit over night, and look at it in the morning. The only things I see, are all these little pin head brown specs suspended in the oil, but no separation. These specs must be the water I have been looking for. No?

--Tony

Tony,
do you have this in a clear jar or opaque container? a clear glass jar might be needed to see the separation.

also try shinning a strong light on the contents..the acid tends to make the oil much darker also like glycerin.

so did you add the methanol to the oil then the acid...this would cause the oil to turn very dark. the acid burns the oil.

-dkenny

Hi dkenny,

Thanks for the reply.

quote:

do you have this in a clear jar or opaque container? a clear glass jar might be needed to see the separation.

Yes it is in a clear jar. I tried the bright light.

quote:

so did you add the methanol to the oil then the acid...this would cause the oil to turn very dark. the acid burns the oil.

If I add the acid to the methanol, the acid boils? What do you do?

--Tony

add it slowly..yes it does boil.
In full size batches I use a 15 gallon plastic drum with 7 gallon of methanol. this leaves lots of empty head space in the drum.

-dkenny

Thanks dkenny!