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Proper way to do Exterification withour darkening OIL
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Originally posted by Biotom:
don't forget to allow for the acid you used, each ml of acid/ltr of oil will result in a titration of about 2 points. so if you use 2 ml of acid/ltr then the lowest t would be 4


what should i do now to reduce the ffa?kindly tell me a method to do in laboratory scale.
 
Registered: January 02, 2015Reply With QuoteReport This Post
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a titration amount from acid you add is not ffa, You can reduce this somewhat by allowing the acid to settle then drain some junk from the bottom, it should be dark brown to black. When you go to the next step, transesterfication the titration amount is added to the base amount of catalyst required for that chemical reaction so that looks after any acid that is left in the mix.


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
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I made the ester from 100% free fatty acids (stearic acid). I used about 150 millilitres of isopropanol to a mass of 196.5 grams of melted stearic acid. I used about 5 millilitres of concentrated sulfuric acid as catalyst. That is more alcohol than most people use in the esterification reaction but it made the ester. I heated the reaction mixture at about 76 degrees centigrade for 10 hours with fast magnetic stirring to get the ester. I would have to find my notes to give a better description of making the esters from free fatty acids. The more anhydrous methanol you use the farther to the right the reaction will go.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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quote:
Originally posted by Biotom:
a titration amount from acid you add is not ffa, You can reduce this somewhat by allowing the acid to settle then drain some junk from the bottom, it should be dark brown to black. When you go to the next step, transesterfication the titration amount is added to the base amount of catalyst required for that chemical reaction so that looks after any acid that is left in the mix.


i allowed to settle the oil overnight but still couldnt get the junk, from the titrated volume i found acid number and divide it by 1.99 to find the ffa. I added 1%v/v naoh to the mixture and it resulted in soap formation, the whole oil turned to soap. So what should i do now.
 
Registered: January 02, 2015Reply With QuoteReport This Post
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I suppose you are seeking a cook book formula for your 18% free fatty acid vegetable oil. So I wrote one that I expect may work. I don't have any 18% ffa vegetable oil to test in with.
Put 500 milliliters vegtable oil with 18% ffa content into a round bottom boiling flask fitted for stirring. Add 100 millilitres anhydrous methanol, begin stirring. Add 2.5 millilitres concentrated H2SO4 (sulfuric acid). Continue stirring while heating at 60 degrees centigrade, for 10 hours. After ten hours, dissolve 8.75 grams 90% potassium hydroxide in 100 millilitres of anhydrous methanol. Add the KOH methanol solution to the reaction liquid from the earlier part of the experiment, with stirring. Continue heating at 60 degrees centigrade with fast stirring for 45 minutes to 1 hour. Remove the heat source, stop the stirring. Two phases should form, a lower glycerine layer and an upper crude biodiesel layer. Remove the glycerine layer. Isolate the upper crude biodiesel layer and purify if you wish. This cook book formula will probably work for your 18% ffa vegetable oil to make biodiesel. It is not the only way to do it. I assume you have equipment to do this with.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
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but still couldnt get the junk

if you are following the earlier info on this thread and used the amount of methanol suggested the junk will be floating on top.
I'm not sure what other information to offer you, I don't understand the info you provided in your last post. please detail the procedure listing the exact amount of chemicals you used/ltr of oil. Did your process cause the whole batch to turn to a jelly like substance?


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post



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quote:
Originally posted by Biotom:
quote:
but still couldnt get the junk

if you are following the earlier info on this thread and used the amount of methanol suggested the junk will be floating on top.
I'm not sure what other information to offer you, I don't understand the info you provided in your last post. please detail the procedure listing the exact amount of chemicals you used/ltr of oil. Did your process cause the whole batch to turn to a jelly like substance?


i added 100ml of methanol with o.5ml h2so4 and added to 50 ml of crude mahua oil, i reduced the ffa to 1.5%. But after this i added 0.5g naoh and it resulted in soap formation, then i tried with 0.5g koh and if forms three layers-lower soap, middle water and biodiesel in top. Does naoh results in more soap formation than koh. Next am going to use heterogenous catalyst.
 
Registered: January 02, 2015Reply With QuoteReport This Post
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Originally posted by praniesh06:
I am Praniesh, studying final year Industrial Biotechnology in Government College of Technology, Coimbatore. I am currently doing my project in "biodiesel production from mahua oil", the oil has a FFA% of 18. I did two step acid pretreatment using 0.35 v/v and 0.30 v/v methanol and 1% h2so4 to reduce the FFA but i could reduce it only to 4 not less than that. I tried it several times but still couldnt reduce it. I performed alkali transesterification reaction and it resulted in soap formation. So what should i do to reduce the FFA less than 1? should i change the quantity or is there any other alternative method? kindly reply me, thanks..


I dont know what the big deal is.. Most people is going about it totally wrong. You only need a one step process. put 10 ml acid per liter of methanol and mix one part oil to one part methanol. stir one tikme let set 24 to 48 hours and thats it. Use your methanol over and over again..


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Location: Indiana | Registered: June 13, 2005Reply With QuoteReport This Post
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Originally posted by Samuel:

I dont know what the big deal is.. Most people is going about it totally wrong. You only need a one step process. put 10 ml acid per liter of methanol and mix one part oil to one part methanol. stir one tikme let set 24 to 48 hours and thats it. Use your methanol over and over again..


the 'big deal' is that there is no right or wrong, but there are certainly more efficient processes.

in lieu of methanol recovery or the desire to store it, people will use a lot less methanol doing a multistage process. the process you suggest using extreme amounts of methanol are in fact appropriate for 100% FFA, but quite a bit on the high side

at 100% FFA, 1:1 methanol to FFA by volume is a molar ratio of 8
at 100% FFA, 1:1 methanol to FFA by volume is a molar ratio of 40

optimum molar ratio is about 4 to get ~92% reduction of FFAs. beyond that you are getting marginal reduction. triple it to a molar ratio of 12 and you might get 96% reduction.

again water is the issue.

the process you describe is effective but it wastes reactor volume. reactor space is money and so you should be using the minimum amount of methanol possible to get substantial reduction

so lets look at a person with an FFA of 10% which is more typical of forum members here:

100 gal of dry (0.05%) oil at 10% FFA
5 gal of methanol = molar ratio of 4
90% reduction after an overnight mix = 1% end FFA

wash it with a caustic solution and dry or carry it straight into transesterification*

*this would have water created in acid esterification = 5 lbs or about 0.6% w/w which is kinda high but still works, yields will be low 90% with some soap formation. carrying AE methanol into TE works much better with starting FFAs of 3-7%
 
Registered: July 06, 2004Reply With QuoteReport This Post
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that was a 1 stage process. for a multistage process for high FFA in a 100 gal vessel you would use 66 gal of oil/33 gal of methanol to be at 4 molar to get from 100% to 10%, then using about 4-5 gal for step 2 to get to 1% FFA

you get the idea. this would only use 37 gal of methanol per 66 gal of processed oil. your reaction would only yield 50 gal of oil

and sure you can reuse the methanol in either process, but it is wet, and needs blended. unless you have methanol recovery reuse is limited. cant change the chemistry as you will create a mole of water for every mole of FFA esterified
 
Registered: July 06, 2004Reply With QuoteReport This Post
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Samuels experience is limited to test tube or mini batches, at least it was when he started posting his "correct way". He also claimed it was "cheaper and easier" to convert WVO to pure FFA to make biodiesel too, among other sorted ideas that made no sense to me for normal sized batches. Maybe fun in a lab on a slow day but that's about it as far as I can tell. I cant see these methods ever making sense on a normal scale for various reasons.
I saw on here where he claimed to be a biodiesel consultant too, not sure if thats for mini batches, I could only assume so.
It is amusing how he came on here to tell everyone they ave been doing AE wrong with that very limited experience though... Wink
Cheers,
Jon
 
Location: Wellington County, Ontario Canada | Registered: February 07, 2008Reply With QuoteReport This Post
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Originally posted by Jon Heron:
Samuels experience is limited to test tube or mini batches, at least it was when he started posting his "correct way". He also claimed it was "cheaper and easier" to convert WVO to pure FFA
Jon


I do a lot of test tube work but i also do large batches as well and have a large setup now. I have 1500 gallons oil that titrates to about 15 with lye that I am getting ready to process..
I already process about 500 gallon with the method i speak of and it does a wonderful job and my oil is not burnt. I use my methanol over and over and it never seems to get wet.. Water is not an issue any more. Anyone who burns (blackens) their oil is doing it wrong. End of story. I read burnt biodiesel is also not good on the motor. I dont remember the source or i would post it.


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Location: Indiana | Registered: June 13, 2005Reply With QuoteReport This Post



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Originally posted by Simple Fuels:

the 'big deal' is that there is no right or wrong, but there are certainly more efficient processes.


There is right and wrong ways.. IF you dont think so you shouldnt posting on this forum.


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Location: Indiana | Registered: June 13, 2005Reply With QuoteReport This Post
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Originally posted by Samuel:
I use my methanol over and over and it never seems to get wet.. Water is not an issue any more.


unless you figured out a way to defy the laws of chemistry, water is most certainly a problem. its only 'not an issue' for the first few cycles until your accumulated water in your methanolstarts to deliver diminishing returns

your process uses 20x as much methanol than the one i proposed, get back to us and let us know how batches 15-20 go for you as your methanol gets too wet to work with. in the end you will have 1500 gal of wet methanol to dispose of or distill and there is no way around that
 
Registered: July 06, 2004Reply With QuoteReport This Post
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If you want more entertaining reading see HERE where Samuel recommends a plastic harbor fright drill pump for 60 gallon AE batches then argues about its suitability. Big Grin
Entertaining if nothing else!
Cheers,
Jon
 
Location: Wellington County, Ontario Canada | Registered: February 07, 2008Reply With QuoteReport This Post
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Originally posted by praniesh06:
the oil has a FFA% of 18. I did two step acid pretreatment using 0.35 v/v and 0.30 v/v methanol and 1% h2so4 to reduce the FFA but i could reduce it only to 4 not less than that. thanks..


Why dont you try using 10 milliliters acid per liter methanol.
Example:

10 milliliters acid,
1 liter methanol
1 liter oil.

1. First mix the acid with methanol.
2. Mix methanol with oil
3. let set for 48 hours in sealed container at around 70-90F
4. Test. It should down to a titration of 1.


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Location: Indiana | Registered: June 13, 2005Reply With QuoteReport This Post
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quote:
Originally posted by Simple Fuels:
quote:
Originally posted by Samuel:
I use my methanol over and over and it never seems to get wet.. Water is not an issue any more.


unless you figured out a way to defy the laws of chemistry, water is most certainly a problem. its only 'not an issue' for the first few cycles until your accumulated water in your methanolstarts to deliver diminishing returns

your process uses 20x as much methanol than the one i proposed, get back to us and let us know how batches 15-20 go for you as your methanol gets too wet to work with. in the end you will have 1500 gal of wet methanol to dispose of or distill and there is no way around that


The water accumulation is not a big deal and doesn't effect the methanol acid stage. There is only so much water accumulation. I will explain how this works.

start out with

10 milliliters acid,
1 liter methanol
1 liter oil.

1. First mix the acid with methanol.
2. Mix methanol with oil
3. let set for 48 hours in sealed container at around 70-90F
4. Test. It should down to a titration of 0-1.

After the first few batches there will be some water accumulation. However when you remove 55% 65% OF THE solution which is 50% oil and 5% 15% methanol and some water from each batch you are removing a lot (maybe half) of water. I didnt test but assume its about 50% of the water is being moved with each batch. Regardless of this amount there no water accumulation beyond a certain point. This i know for sure because i done batch after batch of pure FFA. I done so many batches that i completely used up all the methanol i started with. with each bath i added more methanol because a large amount of the methanol leaves with the FFA-Bio-diesel in each batch.

with 100% FFA you use a lot more methanol because the methanol molecules attaches to the FFA to form Bio-diesel.

Because of always removing more than 50% of the solution with each batch the water accumulation reaches an equilibrium where there can be no more accumulation. Up to this point the total amount of water accumulation doesnt prevent the FFA to Bio-diesel conversion using the methanol acid stage. Thus there is no water issue as I previously stated.

It may take many batches to reach this equilibrium because there is % of methanol leaving with each batch. You are required to add new methanol with each batch to keep the methanol percentage the same. From time to time additional acid will need to be added.

If One were only going to do one batch than you can say you use a lot more methanol with this method. But if you plan to do lots of batches this method in the end doesn't use anymore methanol than any other method. Sure you will always be storing more methanol.

This message has been edited. Last edited by: Samuel,


Biodiesel for cleaner air and fuel independence!
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Location: Indiana | Registered: June 13, 2005Reply With QuoteReport This Post
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Originally posted by Simple Fuels:
your process uses 20x as much methanol than the one i proposed, get back to us and let us know how batches 15-20 go for you as your methanol gets too wet to work with. in the end you will have 1500 gal of wet methanol to dispose of or distill and there is no way around that



Are you nuts? USE more methanol?? 20x as much methanol??

Now you are being ridicules or at the least not considering the facts.

The normal method to process one liter oil to Bio-diesel requires the total of 200 to 250 Ml of methanol for the acid and lye stage.

If you were to process 10 batches of 25 gallons of waste cooking oil the total coming to 250 gallons, you would use about the same amount of methanol with your method or my method. Lets break it down.

At 250 ML methanol per liter oil it would take 62.5 gallons methanol to process 250 gallons of waste oil.

Using the method i use you would use the exact 62.5 gallons of methanol plus additional 25 gallons.

And you dont lose this 25 gallons. its in storage to be use for future Bio-diesel batches.

so where is the 20X times more methanol you claim i use??? Lets not be unreasonable.


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Location: Indiana | Registered: June 13, 2005Reply With QuoteReport This Post



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Hi Samuel,

quote:
Originally posted by Samuel:
...requires the total of 200 to 250 Ml of methanol...
At 250 ML methanol per liter oil...
Just a quick clarification.

Ml and ML are both accepted abbreviations for megalitre which is equal to one million litres
ml and mL are both accepted abbreviations for mililitre which is equal to one-thousandth of a litre






 
Location: ลึก ประเทศอินเดีย | Registered: March 03, 2001Reply With QuoteReport This Post
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Originally posted by Tilly:
Ml and ML are both accepted abbreviations for megalitre which is equal to one million litres
ml and mL are both accepted abbreviations for mililitre which is equal to one-thousandth of a litre



Thanks for the correction.
I was referring to mililitre


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Location: Indiana | Registered: June 13, 2005Reply With QuoteReport This Post
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