[QUOTE]Originally posted by dkenny:
sedona,
the acid needs mixing with methanol before adding to the oil.QUOTE]

Why is that? I've only done the acid process 3 times including the test sample but the two regular batches totaled about 450L.

I couldn't find any real guidance so I just rather slowly poured the acid directly into the oil. Once I stired immediately upon adding it but yesterday I waited until I had measured and poured 100ml in three times. Them I measured and poured the methanol in.

Each time I've gotten good if not great results. I wasn't sure about mixing the alcohol and acid together so I added them to the oil seperately.

quote:

[QUOTE]Originally posted by dkenny:
sedona,
the acid needs mixing with methanol before adding to the oil.QUOTE]

Why is that? I've only done the acid process 3 times including the test sample but the two regular batches totaled about 450L.

Hey guzzler,
Adding the acid directly to the oil tends to burn the oil more so than if you mix the acid and methanol and then add to the oil.

One note: Always wear safety glasses while adding the acid to the methanol and be sure to keep the methanol gently stirring while you’re adding the acid.


-mcguyver

Sorry.

I didn't quite understand what the advantages of acid etherification, is it a better quality off BD?? In the quantities of chemicals I didn't see any difference.

If you have a high titration oil, usually well used oil, and you try the base only method you'll end up with a tank of soap. Hi titration oil has lots of free fatty acids which react with the chemicals and make soap.

Acid esterification converts those ffa's to fuel. Then you can do base method and not make a batch of soap and will give you more fuel.

Hi guys. I am fairly new and not sure this will even be seen but I didn't find any threads that told of a household product to use for the sulfuric acid? I would like to spend a couple months with mini batches before I buy large quantities of acid. also is 93% pure good enough? It's much more economical in my area.
thanks!

dogg4585

I use 98% but I see no reason why 93% would be a problem. The forumal I used was based on 90% and I got the acid required formula from this forum used by one of the other more experienced bd's and it works great for me following the 2 stage acid/base process at beginning of this forum. (3 180lt batches titrating at 13 - 18)

The formula I use to determine acid qty is

ST - RT * 0.2

Where:
ST = starting titration
RT = required titration

Example:
If your initial titration result on high FFA oil was 14 and you would like to bring it down to 3 then:

14 - 3 = 11 * 0.2 = 2.2

H2SO4 / liter wvo = 2.2ml

180lt wvo batch:
180 x 2.2 = 396ml H2SO4

Hope that helps

Whew!! I just want to thank the veterans here. If it were not for you, I would have made a nasty mistake I am new to bd and really want to learn how to make quality fuel. My problem seems to be a familiar one. High FFA. I was just about to try the "Foolproof" method. Thank you Mark, Graydon, Mcguyver and all the others who have guided me away from this process, and given an alternative.

For what it's worth, I have been adding the acid to the oil with the pump on (or mixer if you have it) SLOWLY, at least 20 sec to ad 400 ml of 18mol H2SO4 to 400 L of oil. If you just dump it in, the oil will turn black. Not to worry if you do burn it, the BD produced just has an amber tint to it. The glycerine will be very dark.
After I add the acid, I give it 5 min, (120 GPM pump) then add the methanol 12% by vol). That sucsessfully turned 10.25 oil to 3.5
I will try the *.2 method and post the final value.

I need some help I followed the recipe above for a 1l test batch with the .2 method to determine H2SO4 acid volume. I added the acid to the methanol, mixed for approx 2 hours @ 48-54c. final titration was the same as the first, only difference was, when I added the indicator, it turned pink instead of orange. Regardless, the oil still titrated out @ 7ml NaOH titrant. I am begining to have some doubts about my ability to process this stuff. maybe I am doing something wrong in the titration? Mixing? Heating?
First, I am filtering the oil (1 litre), then heating it to around 51c.
2. I titrated the heated oil. Using NaOH titrant, 10ml Methanol, 1ml WVO, 3 drops indicator solution. I ended up with 7ml of titrant to bring the ph of sample to 8.
3. Using the ".2" method, I added .8ml H2SO4 to 100ml of methanol and mixed that with my oil in a blender for about 5 min. Something interesting was going on, but not surprising, the temp n the blender rose about .1c every 10 sec. After blending,I titrated the oil every 30 min, no change still need 7ml.

Can anybody help?

Thank you.

Hi Marc_s,
There are a couple of possibilities, first, is your acid 100%? What I use is 93% and I have to take that into consideration.
Next, I'm not positive about exactly how others are doing it but I have to continue mixing for the entire time (sometimes up to 24 hours). The .2 method does work but I usually use it to determine how much "more" than 2ml H2SO4/liter of wvo I need. All my oil is real bad (titrates at over 22 KOH) so my figures never run under 2 ml acid/liter wvo. I've come to believe that 2ml would be the minimum and the (.2) method of calculation is just to figure how much more than 2 mls you need.

One other consideration, it is important to keep our methanol in the process. Is your blender well sealed?

Heat also helps the process along. Keeping the temp up makes a noticeable difference. It is tough to come up with a means to do an acid esterification "minibatch". You don't want to spend much money on building something just to do some testing but you know if it works you will want to incorporate the means to perform the acid step into your processor.
My still had a re-circulating pump on it so I did my testing there. I had to have at least 12 liters to make it pump right but that is still considered to be a very small batch (not quite a minibatch).

If you have some 7 or 8 NaOH oil and your processor can do just put 2 ml H2S04 per liter of wvo and make the smallest batch your processor can process and let it run for a much longer time period.


-mcguyver

Thanks Mcguyver,
My acid is 98%. My blender is well sealed, but I have no way of heating it directly. But I did notice that when I mixed the oil, acid, and methanol in it, that the temp went up by .1 degree approx every 10 sec. I am not positive what is causing this temp increase, other than possibly the friction going on inside there. Could it be the acid reaction, combined with the agitation? I do know the action of stirring does produce a minute amount of heat. Anyway this poses a problem for me, as I have to shut down the mixing to let it cool enough to start mixing again. I will try adding more acid and see if that helps, because I did not see any black stuff like the others were describing unless I add it directly to the oil. I am also going to try to use some KOH instead of NaOH and see if that does it quicker. I like the idea of acid esterification to get the oil to a point where I can process it, but it just takes so much methanol, whew! I am definitely going to have to look at a recovery system. My normal oil supply has, unfortunately, quit business. So, now I am forced to use my secondary suppliers as primary and start looking for other, secondaries. C'est la vie, eh. Anyway, thank you for the input, and I will try that, thanks.

Marc

quote:

Originally posted by Marc_S:
Could it be the acid reaction, combined with the agitation?

Yes, it will be the acid reacting with the methanol. It is an exothermic reaction (meaning it releases heat). The same thing happens with water. Perhaps try adding the acid to the methanol gradually, and then adding the oil to it after it has cooled somewhat.

Make sure you wear protective clothing, you do NOT want to get concentrated sulfuric acid on yourself. I would also suggest reading the MSDS available from your acid supplier and take suitable safety precautions.

It is ALWAYS a good idea to know what the effect of mixing chemicals can be (look in the "compatabilities" section of the MSDS) so that you can take precautions.

Perhaps take the time to read this article. I've not read the whole thing yet (as I've just found it), but given where it was published, it will be accurate and informative.

pdf on methanol with conc. sulfuric acid

edit: I've just skim read over that article. It's not what I thought, and will most likely be unhelpful and not mean anything to most people here reading it. I'll leave it there in case it is of any use to anyone down the track.

Thank you Troy,
Rest assured, I am very cautious and protected. Just a note for everyone, please, use all safety precautions when using these chemicals. If you are not sure how something is going to react, ask. There are alot of people here that are more than willing to advise you.

Troy, I knew there would be some heat generated from the reaction. I did not, however, expect that much heat. I have done a little experimentation on this subject, and found that the agitation provided by my mixer will raise the temperature of plain water at a rate of .05 degree celsius every 12-14 seconds. So, even though, there is an exothermic reaction going on, the heat generated by this reaction, is minute. The majority of heat that is being produced in my particular environment, is from the mixing apparatus itself.

Thank you for your input. I will keep your mentions under advisement.

I could not get to the link you posted. If you have a copy of the article, I would love to read it.

Thanks,

Marc

Well, maybe I am doing something wrong. I have tried NaOH, and also KOH as Titrant. I have tried Turmeric for an indicator. All using the FATTA Method for acid esterification. I have yet to achieve any real results worth doing this process. Am I supposed to add catalyst to methanol then add acid before adding to WVO? I am heating and mixing for a minimum 2 hours. Maybe not enough Methanol? Although I do not see how increasing that would help. As I am having alot of residual Methanol after 48 hours. Actually collecting on top of my oil. I am monitoring temp closely and it never drops below 48c. If somebody can offer some advice, I am more than open. As the yeilds suggested would make it worth it, if I can get it to work. By the way, all chemicals are fresh and clean. Except for the oil, of course, If I am to add catatlyst in the first stage, what percentage, volume, etc.? Any help here will be GREATLY appreciated.

Thanks,
Marc_S

quote:

If I am to add catatlyst in the first stage, what percentage, volume, etc.? Any help here will be GREATLY appreciated.

Thanks,
Marc_S

When I was brewing with an Appleseed I would add the acid along with 50% of the methanol and then circulate until the titration dropped to a suitable level, usually 3 to 4. The add the base with the other 50% of the methanol and circulate for an hour, as long as the temp remains up. If it cools to less than 120 F you will need to mix longer in the base stage.

This always worked for me, even with oils that titrated at 15 plus. Now that I have the Bio Pro, I let the computer figure it all out.

Your method of titration and the indicator should have no effect on the outcome, as long as it is accurate. If you titrate with NaOH, use NaOH to process base stage of course.

Norman

quote:

Originally posted by Marc_S:

Troy, I knew there would be some heat generated from the reaction. I did not, however, expect that much heat. I have done a little experimentation on this subject, and found that the agitation provided by my mixer will raise the temperature of plain water at a rate of .05 degree celsius every 12-14 seconds. So, even though, there is an exothermic reaction going on, the heat generated by this reaction, is minute. The majority of heat that is being produced in my particular environment, is from the mixing apparatus itself.

It would greatly surprise me if the mixing produced more heat than the reaction. It may be that there is enough methanol present that the amount of heat generated doesn't increase the temperature greatly.
Is this increase in temperature really a great problem? If it is going up 0.1 degrees every 10 seconds, then you are only seeing a 6 degree increase over 10 minutes. The kind of thermal response I would expect from the exothermic reaction would be a lot more than that.

In regards to your FATTA method, whilst I've not done it myself, there sounds as though there is some confusion of your part.

With any acid base method, the acid stage uses a different catalyst to the base stage. The acid is the catalyst in the acid stage, and your base is the catalyst in the base stage. You should be mixing the alcohol and methanol and then mixing that with your oil (and doing whatever the process requires) and then you have to take into account the fact that you need to neutralise the acid catalyst, as well as any remaining FFA's, in addition to adding the correct amount of base catalyst for the second stage.

Are you neutralising the sulfuric acid catalyst?

Hello Marcs
The Acid stage typically takes longer than 2 hours. Most people do a titration every hour or so and when the titration number stops falling they add 5g+ titration NaOH per litre oil in the reactor to the rest of the methanol and perform the base stage.

Hello StorminNorman
The computer in the BioPro does not figure anything out about the FFA content of the oil. It just runs one set program using one set amount of Chemicals and hopes for the best.

Hello Troy
The H2SO4 and any remaining FFA's are accounted for in the titration that determines the end point of the acid stage.

quote:

Hello StorminNorman
The computer in the BioPro does not figure anything out about the FFA content of the oil. It just runs one set program using one set amount of Chemicals and hopes for the best.

<insert tongue in cheek> What????? I thought it titrated the oil with a little lab tech in a white coat (a shorter version of Daniel) and then adjusted my chemicals accordingly. Well, I guess I learned something. <remove tongue from cheek> It still does a fine job. Excuse me now because I have to drive over to the shop, drain some glycerin and push the WASH button so my 50 gallons of bio is ready in the morning.

Norman

Hello StorminNormin

I am glad I was able to clear that up for you.

Well, thank you all for your help. I am still having problems, but will "just keep swimming", ). There are a couple of things I am going to do different. I am going to try titrating my oil during the mixing process, and also, try adding the methanol/acid more slowly. Possibly I made an error there. I find it hard to believe that I have some "mystery oil" that will not esterify with acid. So, that leaves me to the conclusion the I am doing something wrong. News Flash!! ) The only way to learn is by doing, I have found, and in doing, we make mistakes. Problem is, I do not know what mistake I have made, yet. When I figure it out, I will let you know. 'Til then, if you guys come up with anything that may help or something I should check, and how to check it I will be most appreciative.

Thanks,
Marc_S