I am not an expert on BD or anything else because I believe I can always something new,either by study or by accident. This is the way I do my acid/base conversion, 40 gal clean dry oil titrates at 4. Heat to 125 F add 210 ml sulfuric acid while mixing and 4 gal methanol mix for 2 hrs add 4gals methanol with 32 oz of lye disolved in it. mix for 1 hr turn off heat and mixer let settel for 1 or mor hrs and seperate. transfer to wash/dry tank thru a 1 mic bag filter heat to 185 F while airateing for approx 4 hrs at 185 F. Let settle nd cool to around 100 F filter thru mic filter to setteling tank and then to fuel storage when needed thru 1 mic filter and 5 mic water filter to vehicle tank. yeild has been 94 to 97 percent and I'm lovin it.

Tilly,

I will give this a try. Does the methanol play an active part in the acid's reaction with the WVO? I thought it was just something to dilute the acid from burning the oil during initial mixing.

Also, given the high temp of the preheated oil, is it of concern that much of the methanol would be evaporated off?

Finally, how much time is sufficient for the acid diluted in the methanol to get 6.0 titrated oil down to the 2-3 range?

Thanks!

quote:

Originally posted by Tilly:
Hello Netman, welcome to the forum

There was not enough methanol in the acid stage.
If you used 20% methanol for the reaction, 20% of 190 litres of WVO would be 38 litres of methanol in the total reaction.
Typically people put about 50% of this methanol (19 litres) in the acid stage.

I suggest doing a few test litres if possible before making bigger batches.

quote:

Originally posted by Netman352:
I have been reading this topic with great interest as my WVO typically titrates in the 5-7 range.

Yesterday I tried unsuccessfully to lower the FFA's of a test batch; here are the steps I performed; please chime in if you see where I may have erred.

My batch size was 190liters pre-heated to 55C. The starting titration was 6.0ml. I slowly mixed 1ml per liter (190ml) into a 3 liters of methanol in a separate container, then added this to my 190L batch. I thoroughly mixed the chemicals with the WVO, remixing about every half hour for two hours. I retitrated after 2 hours: still 6.0ml. It was the end of the day so I decided to leave mixture overnight after blending one last time. The next morning the temp had dropped to 41C in the tank. I blended once more, then retitrated: still 6.0ml after 16 hours.

I reheated the oil to 61C and processed the batch using NaoH and 22% methanol. It made biodiesel but the yield was only 80% and the bio was dull, typical of what I get processing 6.0 oil with no acid treatment.

Any ideas?

Thanks!

Hello netman352

The Methanol is an active part of the acid reaction that converts the FFA's into methylesters.

Evaporation is a concern in the Acid/base procedure. You must have a reactor that the methanol can not evaporate out of.

The time for the acid stage will vary. Most people perform a titration every hour and when the titration of the acid stage stops falling they do the Base stage by mixing 5g NaOH+ Titration into the rest of the methanol and perform the base stage.

quote:

Originally posted by antifuel1:
I am not an expert on BD or anything else because I believe I can always something new,either by study or by accident. This is the way I do my acid/base conversion, 40 gal clean dry oil titrates at 4. Heat to 125 F add 210 ml sulfuric acid while mixing and 4 gal methanol mix for 2 hrs add 4gals methanol with 32 oz of lye disolved in it. mix for 1 hr turn off heat and mixer let settel for 1 or mor hrs and seperate. transfer to wash/dry tank thru a 1 mic bag filter heat to 185 F while airateing for approx 4 hrs at 185 F. Let settle nd cool to around 100 F filter thru mic filter to setteling tank and then to fuel storage when needed thru 1 mic filter and 5 mic water filter to vehicle tank. yeild has been 94 to 97 percent and I'm lovin it.

Antifuel1,
Sounds like you have a sweet method that works very nice.
In an effort to learn more about your method, I do have a few questions.
Are you doing this in an appleseed?

Have you ever titrated between the acid and base?

How did you determine the 6g/liter of base?

Do you ever see any dropout on 3/27?

Thanks and keep up the good work,
DD

dandy I arrived at approx. 6g/l by expermenting. I did titrate after acid stage last and I was at 1.5-2 It passed 3/27 test 10 times strait so I have not been testing it since. I feel the filtering thru 1mic bag before demething it helps to remove missed glyc and soap before useing an adaption of GL's drying method. This is only my opinion, maybe it works with the mix of oils I use[unknown]. Some of it is only used for a couple of hrs. an some is prety rank. I am expecting better results once I get my cf in operation.I want to try running it thru the cf before during and after the process. I want to see if putting thru the cf before demething it will improve the the percentage of return and also produce a cleaner fuel with less time in the dryer ,also when I build my vac dryer collecting a higer grade methanol because there should not be any water in it. The whole picture gets clearer as all of the good ideas get put in the right spot only problem is it the ideas keep improveingand the picture keeps getting better. Keep up the good work everyone. The only dumb idea is the one that is not checked out and done with safty as the first step.

I have a quick question. When you're titrating, you titrate it mixed up and everything? What would happen if you let it settle and then titrated it again? I'd think this would let the sulfuric acid settle out and lower the titration.

My initial titration values are much higher than most of yours (in the mid-20s) so I expect that I'm going to create too much water to run the reaction to completion. Therefore I'm considering draining and then running the base reaction (with more methanol, of course), maybe even running a second acid reaction. Thoughts?

Hey RUBI,
My oil usually runs around 22 or 23 KOH. I use the acid/base method routinely. You do make some water that does wind up becoming soap but the additional soap usually isn't enough to justify the additional methanol you would have to use if you dry the wvo before going on to the base stage. If you use KOH it will wash out easily.

-mcguyver

Hello rubi

Yes, you titrate everything.
The Sulphuric and methanol will be together and you can not remove one without the other.

Mcguyver, how long do you usually need to mix your acid stage before the titration stops dropping? I only mixed it for three hours for comparison purposes with another method. Should have been titrating it every hour, but as my last post says I wasn't sure how. So my NaOH titration only dropped from 29.5 to 15 and 16 for the two batches I ran.

Since KOH titrates slightly higher than NaOH, and my titration was a bit more, it won't be a direct comparison, but it should give me an idea.

Thanks, RUBI

Hey RUBI,
I usually run mine for 24 hours before I even start checking the titration. I know that's a long time but that is just what it takes. By the time I get 3 or 4 more hours in the titration has finished dropping. Unfortunately I don't have the time to really "baby-sit" my processor like I should so I use a 12 hour timer and usually check it at the first and second 12 hour interval and then guess the rest of the time needed and set the timer for that. The savings in "production losses" is significant enough to justify the time/money spent running the pump and heating element. I do my processing in an Appleseed so the heat loss is minimal. If I don't do the acid step my glycerin production is almost 50%.

Your oil is pretty bad stuff. You will most likely have to do two acid steps to get the titration down were you want it. I have done this before and found it works better if the water is drained between steps. You have to replace the water/methanol you drain with methanol.


-mcguyver

What would be the LOWEST titration that it's worth the effort to do the acid stage ?

Hi Yair,
It's hard to give it an exact number to say this is the point at which you should do the acid/base process.

I've had oil that titrated in the low 7's and still produced why too much glycerin and I benefited in doing the acid/base process.

Basically you should do a minibatch on an oil and immediately after you get done agitating the minibatch fill a 100ml graduated cylinder and wait to see the results. If you're getting 35 or 40 ml of glycerin then it is likely that the cost of the acid and the additional electricity out-weighs the cost of the large amounts of catalyst and the lower production yields.

-mcguyver

Hi mcguyver
Thanks for your answer.
I get about 20% glyc.
I titrate the oil at about 1.7 ( a mixture of 2 different sources).
The additional electricity is nebligible, so maybe it really may be worth the effort for the additional yeald.
Your thoughts?

quote:

Hi mcguyver
Thanks for your answer.
I get about 20% glyc.
I titrate the oil at about 1.7 ( a mixture of 2 different sources).
The additional electricity is nebligible, so maybe it really may be worth the effort for the additional yeald.
Your thoughts?

Yair,
The only way to know for sure would be to do some minibatch test to see if the yield would change however, I would wager against any significant increase in yield. With oil that good I would just process it and enjoy the bd. 20% glycerin isn't out of line at least not here at my shop.

If you do pursue this test please let me know how it turns out.

-mcguyver

Hi mcguyver
Thanks
If I do continue, I'll keep u posted

yair-BHFC,
a while back I did the math comparing just the difference in KOH usage and I found the break even was around 5 KOH. above this Acid/base if the end point was 3, was cheaper, I would guess that if your oil is already 1.7 then you would see and increase in yield. also I would have to ask if it titrates that low why think about acid/base?

-dkenny

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.
What am I missing?

Thanks,
Greg

quote:

Originally posted by girl mark:
Here's the original FATTA method. This is essentially what I did when I did acid-base.

***************
The FATTA method - Development by Kevin Tidball and Michael Fox
click here for FATTA acid-base method thread from several years ago

First stage acid catalyst (to esterify the FFA)
Oil 1000ml (1 litre)
CH3OH 100m (Methanol)
H2SO4 (conc. 98% 18M) 1-2ml
React at 48- 54C until titration falls to a minimum hopefully 2.6 ml could take longer than 2 hours. Greater levels of acid will raise the titration end point.

Second stage alkali catalyst (transesterification of the oil)
100ml methanol
6.4grams of NaOH
(3.5grams for catalyst + 2.9 grams for acid neutralisation if titration of 2.6ml achieved)
React at 48- 54C for 1 hour.
Settle and separate


Mark

Ok, I'm a novice, so I have to ask:

In the second line, the "CH3OH 100m (Methanol)" Mark is really speaking of 100 ml methanol, right?

Also, in the second line of the BASE side of the reaction, she writes, "2.9 grams for acid neutralisation if titration of 2.6ml achieved" Is the 2.9 supposed to be a 2.6, or did I miss something?

And, the BIG BIG questions:

Can I practice this in a Dr. Pepper bottle?
Can I do this Acid / Base in my appleseed processor, or will it gobble up all the metal?
If water shuts down the reaction, how do i remove the water DURING the reaction?
Can I do this acid / base process AND an 80/20 - 80/20 base base method, so, I'd call it an "Acid / Base / Base" method.

Anyone?

Thanks,

Frank, a newbie making bio in his backyard in hollywood.

paperstreet,

quote:

Ok, I'm a novice, so I have to ask:

In the second line, the "CH3OH 100m (Methanol)" Mark is really speaking of 100 ml methanol, right?

Also, in the second line of the BASE side of the reaction, she writes, "2.9 grams for acid neutralisation if titration of 2.6ml achieved" Is the 2.9 supposed to be a 2.6, or did I miss something?

And, the BIG BIG questions:

Can I practice this in a Dr. Pepper bottle?
Can I do this Acid / Base in my appleseed processor, or will it gobble up all the metal?
If water shuts down the reaction, how do i remove the water DURING the reaction?
Can I do this acid / base process AND an 80/20 - 80/20 base base method, so, I'd call it an "Acid / Base / Base" method.

Anyone?

yes Mark mean 100 ml of methanol, but this is only for the acid stage. I actually use 120ml.
I ignore the amount needed to 'neutralizing' the acid. titration tell you the amount of base needed.

removing the water for a home brewer is difficult. for me oil that titrates about 18, I just let the oil settle overnight and drain about 1/2 amount of methanol that I started with. if you need to drain make sure you add the same amount of methanol to the methanol needed for the base stage.
80/20 - of 2 staging base- yes

doing a DR pepper sample. possible but not easy its a slow reaction. think hours not minutes.

I do all mine in an Appleseed. I don't have any plastic in the pumping circuit..

-dkenny

Hi:
I'm not a chemist so I'm having a little bit of trouble understanding the Acid Base process. The purpose is increase yield of BD and reduce soap right? If I convert the FFA to DB by adding Acid and now have acid BD form the acid that I added, and now have to add more KOH to neutralize, don't I create salt water which will now create a lot more soap? If I don't add extra KOH there wouldn't be enough for transesterification, no? What am I missing? Thanks for your help. lcc