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Cannot get titration to drop
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Hello.
I am struggling to process a batch of high titrating oil using ae method. Hoping for any suggestions.
The oil titrated at 16 KOH. 100 litres
The oil has been filtered to 75 micron and thoroughly dried using heat, bubble drying and vapour extraction for 3 days and passed hpt.
I set temp at approx 55-60C.
I added (16-3)*0.2 ml of 98% H2SO4 per litre = 260ml into 10l methanol.
I mixed for 24 hours and maintained heat throughout. I checked titration over the 24 hours and it rose to 20 and then dropped to 18. There was no drop out of water/gunge after 8 hours of settling.
I tried a further 5 litres of methanol with 130ml of acid. Another 24hrs mixing and settling still gives 18 titration and no sludge of any kind.
I don't know what to try next as I have 300litres of this oil and I haven't got a supply of better titrating oil.
Any ideas?
 
Registered: May 10, 2013Reply With QuoteReport This Post
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Is your reaction vessle closed? at those temps you will lose the methanol in a hurry.


" 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 X1:

The oil has been filtered to 75 micron and thoroughly dried using heat, bubble drying and vapour extraction for 3 days and passed hpt.

Any ideas?


This particular statement has me a bit concerned.

Hot pan testing is fine for rough go/no-go indications for normal single stage reactions but I prefer to have a quantitative measurement for complex reactions like the one you're doing.

Esterifications are problematic enough.. those starting out in the high teens are just nightmares looking for an excuse to come true.

In my opinion, a hot pan test is not good enough. AE processing for lower titrations is not tolerant of water.. and at the higher titrations, its even worse.

I'm not saying the water was certainly your problem, but that's where I would start off looking.


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Registered: March 09, 2006Reply With QuoteReport This Post
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Yes the reactor is sealed but does have a vent to outside. Do you think I have lost the meth?. Is there any way to test?
 
Registered: May 10, 2013Reply With QuoteReport This Post
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the vent should have a good lenghth of pipe going upward to allow the methanol vapours to condense then fall back into the reactor. It would depend on your vent setup as to how much methanol you lost.


" 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 Murphy:

I'm not saying the water was certainly your problem, but that's where I would start off looking.


I agree with Murphy about the H2o. Not familiar with your processor , How much did you drain looking for water ?? Sometimes my processor will initially drop a little good looking stuff before the chocolate milk comes out Roll Eyes
We routinely AE oil over that mark and do it in two stages. If we don;t see a reduction after the first stage we always see some chocolate milk. We then replace the drained volume with methanol and hit it again with Acid. Did you pretreat with Glycerin ? Glycerin retains allot of caustic and would nerutralise the Acid.
Good luck
regards to all
Tom


1999 K3500 Dually with a new AMG 6.5TD turned up a bit by John Kennedy
Chevy DMax Totaled thanks to a 20 year old in a Mustang
Mercedes 300CDT
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Location: Decatur, Al | Registered: September 03, 2009Reply With QuoteReport This Post



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Yep glycerin was my problem. I gly washed and didn't get full volume out. I assumed that it had lost the volume in biodiesel as there was a good layer of oil floating on top. However when I drained the reactor there was about 5 litres of solid brown gunk stuck to the bottom of the vessel. Obviously this had been sitting there neutralising any acid added. You live and learn. Try, try and try agian. Thanks for your help.
 
Registered: May 10, 2013Reply With QuoteReport This Post
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Glad you got it figured out.
We don't pretreat much anymore as most of our oil T's pretty high ( usually 8-18 ).
Be careful Pretreating with Glycerin from a previous AE batch. If any water is present in the glycerin it can stay suspended in the oil. ( Scratched my head over that one for a few days )
It dropped right out after dewatering.
Good Luck
Tom


1999 K3500 Dually with a new AMG 6.5TD turned up a bit by John Kennedy
Chevy DMax Totaled thanks to a 20 year old in a Mustang
Mercedes 300CDT
John Deere
On B99.?
 
Location: Decatur, Al | Registered: September 03, 2009Reply With QuoteReport This Post
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quote:
Originally posted by X1:
Yep glycerin was my problem.


Huh? What? Where?

Would someone please point me to the location in this thread where pretreating with glycerin was even mentioned?


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Registered: March 09, 2006Reply With QuoteReport This Post
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I'd like to chime in on this thread and any advice as to how I should proceed would be greatly appreciated.

I have a 200 liter batch that titrated at 33 KOH.
I used the Dkenny calculation to get 5.1mils per liter.

1023 milliliters of H2SO4 and 24 liters of methanol were added to reactor and kept at a temperature between 60-65C.

After 2 hours the T was at 18.
After 4 hours the T was at 16.
After 6 hours the T was at 13.

I couldn't maintain the temperature overnight. So in the morning I heated the unit back up and took another sample after 2 hours of it sitting between 60-65C.

The results were 18T KOH.

I drained off a gallon from the bottom because I wanted to see what settled out. Before I dig this batch even further in to the ground I wanted to see if anyone could offer up a direction I should explore.

Thanks
 
Registered: September 16, 2012Reply With QuoteReport This Post
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Someone somewhere here on this site said 14 is the magic number.
T's over 14 should be done in 2 stages. Ronny is right you made water
in your processor and it stopped the reaction.
Follow Ronnies advice and you should see another reduction.
Anything over 14 I split the acid dose in half and do 2 stages.
T @ 33 Eek

You using trap grease ??
Let us know how it turns out.
regards
Tom


1999 K3500 Dually with a new AMG 6.5TD turned up a bit by John Kennedy
Chevy DMax Totaled thanks to a 20 year old in a Mustang
Mercedes 300CDT
John Deere
On B99.?
 
Location: Decatur, Al | Registered: September 03, 2009Reply With QuoteReport This Post
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posted Hide Post
quote:
Originally posted by Ronny:
quote:
Originally posted by Murphy:
Huh? What? Where?

Would someone please point me to the location in this thread where pretreating with glycerin was even mentioned?




Hamilton 205's first post.


Ya. but that was Hamlin who was purely speculating that said it.. not the original poster..


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Waste Oil Heating - Biodiesel Systems
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Registered: March 09, 2006Reply With QuoteReport This Post



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quote:
Originally posted by X1:
I added (16-3)*0.2 ml of 98% H2SO4 per litre = 260ml into 10l methanol.
Any ideas?

Adding Acid directly to the methanol makes me pucker up worse than handling the acid.
Pretty sure it was DKenny that said you can pour the acid directly in to the processor and
then add the methanol. I add the acid first to the hot oil in a port on top of the processor
with the pump running then inject the methanol. Mr. Kenny was right as long as you get them both in there and mix it works. You don't get the excitement of watching the Acid when it hits the methanol but it's a whole lot safer.
regards
Tom


1999 K3500 Dually with a new AMG 6.5TD turned up a bit by John Kennedy
Chevy DMax Totaled thanks to a 20 year old in a Mustang
Mercedes 300CDT
John Deere
On B99.?
 
Location: Decatur, Al | Registered: September 03, 2009Reply With QuoteReport This Post
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jv3 where did you take the last t samle from,did you mix well when you reheated the batch? I doubt that water from the ae reaction on it,s own would be sufficient to stop this reaction. water from wet oil or that contained in the lower purity sulfuric acid combined with that produced during the reation could cause the process to end with this level t oil. Anything over t20 should be done in two stages.


" 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 only have to have one misadventure pouring methanol into acid to NEVER do it again! the acid that landed on my clothing and shoes destroyed them. lucky for my face I was wearing a shield! The acid methanol stains are still on the side of my processor tank as a reminder that mindless actions are dangerous! that eruption blew acid and methanol 5 ft in the air.
always add methanol to the oil first mix well then add the acid, you will note that if you add the acid before the methanol the resulting biodiesel will be darker than if you add methanol first.


" 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 clarifying that for me Tom !!!
I too have stains on the side of my processor. I added the Acid to the
Methanol and it still blew it out of the Cam Lock quick connect on top of my Methoxide tank.
( Only a 2 inch hole with a towel over most of it )
Right again about the acid darkening the oil but after the above event I was more than concerned about pouring acid in to the processor with Methanol in it. Any other repercussions from doing it
Acid first ??
Thanks again for all you have done here to help us !!
regards
Tom


1999 K3500 Dually with a new AMG 6.5TD turned up a bit by John Kennedy
Chevy DMax Totaled thanks to a 20 year old in a Mustang
Mercedes 300CDT
John Deere
On B99.?
 
Location: Decatur, Al | Registered: September 03, 2009Reply With QuoteReport This Post
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quote:
Originally posted by Biotom:
jv3 where did you take the last t samle from,did you mix well when you reheated the batch? I doubt that water from the ae reaction on it,s own would be sufficient to stop this reaction. water from wet oil or that contained in the lower purity sulfuric acid combined with that produced during the reation could cause the process to end with this level t oil. Anything over t20 should be done in two stages.


I have a sample port in the middle of the reactor. The batch was pretty well mixed when I took the sample.

I'm going to push forward with a second acid stage. So I should remove the same volume as the amount of methanol added?

Well here's a quick addition. This morning I drained off the 6 gallons and was prepping the unit to start a second AE. However the average T is 10. I did about 6 titrations to double check.

Should I just proceed with the base stage?

This message has been edited. Last edited by: JV3,
 
Registered: September 16, 2012Reply With QuoteReport This Post
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if you really want to know how well the ae worked I find it best to mix the sample before draining the junk do titration and then allow the batch to resettle. there is no way to know exactly how much sulfuric acid remains in the mix otherwise.

Ronny re read that paper (I also have it) and see what titration level Dr Van Gerpin was working with. There is enough experiance on this site that suggests a single stage ae is sufficient for oil titrating at 20 or below. Having said that the higher the T the more important it is to have dry oil and high quality acid as the water in these combine with the water produced in the reaction and can abruptly stop the reaction.


" 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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at t33 you require two stages for ae

my oil titrates about t16 and this is processed in one stage, BUT the oil must be dry!


" 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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Jones do you understand the acid esterfication process?


" 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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