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My history with A/E has been poor at best. Usally my oil source is good so I don't have to worry about the extra steps but recently have been getting poor oil again.
My latest batch titrated at 16 KOH. 36 gal batch. I added 400 ml acid (basically 3 ml per ltr) with 4.32 gals of methanol (this is 60% of total methanol needed) I mixed this concoction for an hr.(heated)and let it sit the rest of the day. It remained warm during this period of time. I titrated it the next day and had no change, still titrated @ 16. There was very little "glop" at bottom of tank (less than 1 cup) that I drained off. I let it sit for a few days, reheated it with same T results. Frown O.K. where the heck do I go from here? I hate to throw this away and also I have quite a bit more of this source oil. My reacting tank had just been cleaned prior to this batch. Heeeelllpppp.
 
Location: yes | Registered: July 16, 2011Reply With QuoteReport This Post
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what color was the drainage?

T16 + T 6 for the acid amount you used + T22. therefore you have had some reaction now it's to determine what stoped the reaction, either water in the oil or lack of heat.
the acid amount you used was high, .095 * T = 1.52 ml/ltr of oil. also with that much methanol there is a good chance that much of the acid/methanol is floating on top.

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


" 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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hello
during the a.e., titrate every hour of your rx until you get it down to where you want it. i dont think that the batch is wasted. do you have a way of distilling the methanol out of your reactor? . the acid will make it look a little milky and maybe your reaction time was way to short. not sure why it didnt even come down at all. wish i could help more.

Cooper
 
Location: Bioville Ohio | Registered: June 30, 2010Reply With QuoteReport This Post
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the acid produces a very dark brown to black drainage, only if the oil is wet will the drainage be milky!!!!!


" 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 have surrendered on this batch. I have ordered acid that is 98% and will try again with this. Unfortunately my supply of crappy oil is continuing. I put another 35 gallons in my tank and heated it. It titrated at 26. Because I did not have my new acid I just let it sit in the reactor tank (plastic and translucent). Now it seems to have seperated.....top 10 gallons a dark color and the bottom 25 gallons a very light color. When I mixed it under heat it was all a light color (which I thought was going to give me a very low T number) Now i'm wondering if I should get rid of the bottom 25 gallons, or perhaps the top 10. Any thoughts on this? After 1000 gallons of good oil it looks like my education is starting all over. Smile Thanks Bill
 
Location: yes | Registered: July 16, 2011Reply With QuoteReport This Post
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Bill AE seems to me to be just like everything biodiesel. Seems hard at first and then gets better and finally easy. Utahbiodieselsupply.com has a good procedure printed out that was written by graydon's friend norman. My first 160 gal batch, titrated at 16 from some oil that had been stored for over a year. AE on first mix, only dropped to 12 and I drained off 10 gallons of stinky junk, added back some meth and did the AE again, got to 6, when ahead with 80/20 and had to go back and do 20 again so I could pass 27/3. Second batch was much better, just one pass at the AE and 80/20 gave us a great batch. Not sure if the first batch didnt like the tank, my acid, how I combed my hair but it gets better. Take your time, try it again, it's just oil.


2006 Duramax, B100 200k Acadiana Biodiesel
US Army Retired
He that can have Patience, can have what he will
- Benjamin Franklin
 
Location: Hill country, Texas | Registered: February 07, 2011Reply With QuoteReport This Post



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many processors contain caustic material even after the biodiesel has been drained. the causic biodieseland or byproduct is in every nook and cranny throughout the plumbing. This caustic material greatly affect the ae process by neutralizing some of the acid. Still one big problem is wet oil I know, no one has wet oil Big Grin the proof is in the pudding so to say, just check the color of the drainage, dry oil produces dark brown to black drainage, wet oil produces milky to carmel colored drainage. heed these signs and you will have no problems with AE.


" 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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Thanks for the help........and encouragement. I was thinking (I know dangerous) could I take a test sample from top of the tank and heat it then titrate, and then do the same from oil at bottom. would this determine what to keep and what to discrard?
My 98% acid is due to arrive tomorrow. Yeah (on the negative side... this may eliminate on more excuse for failure) Smile
 
Location: yes | Registered: July 16, 2011Reply With QuoteReport This Post
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don't look at it as a failure, it's a learning curve!


" 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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Yeah, even though it feels like a learning boomarang sometimes


2006 Duramax, B100 200k Acadiana Biodiesel
US Army Retired
He that can have Patience, can have what he will
- Benjamin Franklin
 
Location: Hill country, Texas | Registered: February 07, 2011Reply With QuoteReport This Post
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Your problem is quite likely to be the very limited reaction time you used.
If your oil titrated 16 the next day then you did achieve some reaction because the 3ml of H2SO4 you used would have added another 4.2 to the titration.

AE takes much longer to perfrom than base transesterfication. If you ran your reactor for five minutes and then turned the mixer off when performing a base transesterfication you would not expect to achieve a complete reaction.
AE works the same way. Once you stop mixing, the reaction stops and the Methnol/H2SO4 separate from the oil just like the glycerine does when you perform a base transesterfication.

I hour is not normally long enough for AE.
You should have run the reactor a number of hours before turning the mixer off and letting the methanol/H2SO4 settle out over night.

HTH
quote:
Originally posted by BuilderBill:
I mixed this concoction for an hr.(heated)and let it sit the rest of the day... I titrated it the next day and had no change, still titrated @ 16...Heeeelllpppp.
 
Registered: January 07, 2012Reply With QuoteReport This Post
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BioGoGo has a point. When acid is added to the oil it should increase the titration, initially. But I calculated 3 milliliters of sulfuric acid in one litre of oil should take 6.3 grams KOH to neutralize. That's with pure acid and KOH. So if you had a titration of 16 initially then added the H2SO4 acid your resulting initial titration (KOH) should be 22. I think your AE worked as it dropped the titration back down to 16. And AE takes longer than base catalysed transesterification. I think 6-8 hours at temperature with mixing will make your titration go down more. If you started with dry oil, otherwise your proceedure sounds good to me.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post



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I have a question regarding reprocessing. I tried AE but did not have enough "overnite" heat. I have since bought a bucket heater to maintain over night temps (my current heater has to have fluid circulating to work). Can I simply reprocess this oil? Thanks
 
Location: yes | Registered: July 16, 2011Reply With QuoteReport This Post
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for AE just reheat, the reaction will continue!


" 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 am not sure what you mean by "reprocess". Are you going to remove the waste and add more methanol and H2SO4? If this is not what you mean can you be more specific.

Also, When you perform the AE stage you should continue mixing until the reaction is finished. The AE reaction takes place in the oil phase so as soon as you turn the pump off the reaction stops. Just like in the base stage.
The reaction is finished when the titration stops falling.
You can then go immediately to the Base stage, or if you plan on trying to drain some of the Methanol/H2SO4/water mixture you would turn the pump off and allow everything to sit overnight. The waste will either settle to the bottom or float to the top and you can then remove it.
When you finish removing the waste turn the pump on for a while and check the titration.
This is now the titration number you will use for the base stage.
quote:
Originally posted by BuilderBill:
I have a question regarding reprocessing. I tried AE but did not have enough "overnite" heat. I have since bought a bucket heater to maintain over night temps (my current heater has to have fluid circulating to work). Can I simply reprocess this oil? Thanks
 
Registered: January 07, 2012Reply With QuoteReport This Post
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I was refering to the AE step of the process. Sorry for not being clear. Look like Tom was able to put his mindreading skills into action. I was able to drain off about a gallon of crud from this incomplete batch, mostly black, little bit of tan. Im thinking of replacing this amount before repeating my AE attempt. I will post results...........I promise Smile
 
Location: yes | Registered: July 16, 2011Reply With QuoteReport This Post
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Is this a different batch from the one you started the thread with?
If you drained some of the waste you will have drained some of the H2SO4 and some of the methanol so you will probably need to add more.
I would run the pump for a few minutes and then check the titration first.
Do be aware that just heating is not sufficient. You have to mix too.
quote:
Originally posted by BuilderBill:
I was refering to the AE step of the process. Sorry for not being clear. Look like Tom was able to put his mindreading skills into action. I was able to drain off about a gallon of crud from this incomplete batch, mostly black, little bit of tan. Im thinking of replacing this amount before repeating my AE attempt. I will post results...........I promise Smile
 
Registered: January 07, 2012Reply With QuoteReport This Post
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This is actually a different batch than the one I started this thread with. Sorry for any confusion. This batch has had NO base added, it is just oil, methanol, and acid. Awaiting new heater and then I will start AE process over. I did try to AE this batch previously but did not have sufficient "overnite" heat to get a reaction. I have drained about 2 gallons of gunk from this "uncomplete" AE batch. I plan on re-mixing this batch and using my new "bucket heater" for a heated 12 hr. reaction time. Will this be sufficient time? (12hr.)
 
Location: yes | Registered: July 16, 2011Reply With QuoteReport This Post



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yes mix it well and titrate, a ph meter works well for this, you need to add back sufficient acid to get the ph down to 1 and an amount of methanol equal to the amount of drainage. If this happens again (loss of heat) just heat and as tilly says re mix, the reaction will continue!


" 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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You seem to be confused about the mechanics of the AE reaction.
For some reason you seem to think that the reaction continues after you turn the pump off and some form of heating only is then required. That is not the situation. Let me stress that when you turn the pump off the reaction comes to an end. From that point the only thing that then happens is the waste will slowly settle out.
In an earlier post you said that you have a heater in your reactor that works with the pump. That is all the heat required for the reaction.

For all practical purposesTHE REACTION DOES NOT CONTINUE AFTER YOU TURN THE PUMP OFF

12 hours of mixing should be sufficient time.
I normally check the titration every hour or two and when the titration stops falling the reaction is through and I turn the pump and heater off. If I want to remove the waste I then let it sit overnight and the waste usually settles to the bottom but occasionally it will float to the top. No further heat is normally required during the overnight settling period.
This settling out of the waste will result in a further reduction in the titration and it seems that some people are confuse this with a continuing reaction after the pump is switched off.

Here are two papers that explains AE and the crucial part agitation/mixing plays in the reaction.
Kinetic Study of Esterification of Free Fatty Acid in Low Grade Crude Palm Oil using Sulfuric Acid

A kinetic study of the esterification of free fatty acids (FFA) in sunflower oil

If you have any other questions please feel free to ask.
quote:
Originally posted by BuilderBill:
This batch has had NO base added, it is just oil, methanol, and acid. Awaiting new heater and then I will start AE process over. I did try to AE this batch previously but did not have sufficient "overnite" heat to get a reaction. Will this be sufficient time? (12hr.)
 
Registered: January 07, 2012Reply With QuoteReport This Post
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