BIODIESEL & SVO DISCUSSION FORUMS





Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Biodiesel Quality    complete transesterefication

Moderators: Shaun, The Trouts
Go
New
Find
Notify
Tools
Reply
  
complete transesterefication
 Login/Join
 
Member
posted
Hi all,
just curious is it complete tranesterification reaction
Used 99% lab grade Naoh 5g, 220ml Methanol 99.9% VIRGIN GRADE and 1000 ml used cooking oil , not dewatered.
Used oil titration shows 2.79 mg KOH on 1 g used oil.
Reaction was complete in Plastic PET bottle.
See picture below.Thats after reaction and settling 1 hour.
Just interesting , is it supposed to be more glycerol on bottom of bottle. or is it ok?
thanks.

Imagebiodiesel1.gif (41 Kb, 42 downloads)
 
Registered: August 14, 2012Reply With QuoteReport This Post
Member
posted Hide Post
It may be different with other oils but what I see with the wvo I use is that when the sun shines through the sample, if it has a red color then the process is not complete. Not dewatering is a mistake IMO since the water will carry the caustic to the soap making reaction that happens simultaneously with transesterfication. Do a 3/27 test, that’s 3ml of the biodiesel from your container and mix that with 27ml of methanol. Any unreacted oil will drop to the bottom at room temp within 10 minutes, also note the clarity of the methanol at this time, it should be clear not cloudy.
I use 6.5 ml/ltr of NaoH for used oil and that amount works best for me, it is rare to fail 3.27 test.


" 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
Member
posted Hide Post
hello, just did 27/3 not sure 3 or 4 ml (i put liquids in to bottle, shaked, put it into baker to make photo ) liquid appears bit cloudy, so it is not complete reaction? Also i did photo 1 minute after shaking in bottle, it is not enough ime to drop unreacted oil down..
it appears that leave water was my mistake.
Also just want to ask , if FFA is 2.7 mg KOH , same amount to neutralise FFA will be 2.0 mg NAoh in 1 g used oil.
Do i need to add more Naoh in my case?
many thanks in advance

Image27_3.gif (48 Kb, 23 downloads)
 
Registered: August 14, 2012Reply With QuoteReport This Post
Member
posted Hide Post
3/27 is just that, 3ml of biodiesel in 27 ml of methanol, not 3 or 4 ml. you need to be more accurate, having said that, once the batch passes 3/27 then I often do 4/27 and 5/27 just to see when the dropout starts. IMO, for what it is worth, a batch that can pass 5/27 with no drop out at room temperature in 10 minutes is of higher conversion than that which just passes 3/27, do we need to push the reaction that far NO! When you do the 3/27 tilt the glass so any dropout can gather at the bottom/side corner.
Did you use enough NaoH Not for me, 6.5 + 1.93 (2) = 8.5 gr NaoH or 7 + 2.7 (3) = 10 gr for KOH. When you titrate with KOH and then process with NaoH divide the titration amount by 1.4 as NaoH is a stronger caustic so you need less of it.


" 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
Member
posted Hide Post
thanks Biotom ,
it appears from what was said to me that I used not enough Naoh..
As I said previuosly I used 5 grams 99% Naoh.
Anyway that was my first Dr pepper reaction.
Will try use in future 5g Naoh + required Amount Naoh to neutralise FFA.
Thanks again. Smile BTW is it any chance to complete reaction now ? Shall I add more Ch3ONa and complete reaction?
 
Registered: August 14, 2012Reply With QuoteReport This Post
Member
posted Hide Post
you can reprocess but it would be good to know how much oil droped out in your 3/27 test, this is unprocessed oil that at this stage should be free of ffa, normally a reprocess is done with 1gr caustic in 50ml methanol per ltr. of oil to be reprocessed. First decant the biodiesel from the byproduct this will will help the push the reaction to completion once you add the methoxide. (pass 3/27) In this case though I think 1 gr won't geter done, try 2 or 2.5 gr/ltr/50ml methanol per ltr of oil. Heating your oil back up to processing temperature my be problematic as it contains methanol. try placing your bottle into hot water adgitating often to absorb the heat.


" 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



Member
posted Hide Post
Excelent advise, will do tommorow and post update.
 
Registered: August 14, 2012Reply With QuoteReport This Post
Member
posted Hide Post
this morning done another 27/3 test and left it to rest all day.
just uploaded picture of dropped triglycerides, there is 27/3 ml methanol/biodiesel, looks like it's about 0,1 ml? no idea Confused

another thing.. Just done filter path analysis on SEM (filtered 50 ml my bio trough 0,8 mm nitrocellulose membrane, looked at it under Scanning electron microscope, performed EDX analysis, SEM EDX analysis clearly shows Na presence on filter patch about 0,7 % of total elemental weight.Rest is Oxygen and carbon.
Now question come - what i saw on EDX elemental analysis - soap? .. most likely, just need to discuss further. And if it's not soap then i dont know what to think Confused
And another thing viscosity on my unwashed bio was 5,0 Centistoke.thats i think not bad result for rapeseed oil(i suspect mine is used rapeseed oil.)

Image27_-3-drop-oil.gif (31 Kb, 28 downloads)
 
Registered: August 14, 2012Reply With QuoteReport This Post
Member
posted Hide Post
read the 3/27 after 10 minutes!!! as for your other tests ? for sure there is soap, methanol, water and probably some caustic in the unwashed biodiesel.


" 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
Member
posted Hide Post
Hi bbarclay,
If your 3/27 test is in a sealed container then you have a failure. Drop out should never occur in a sealed container. I recommend you wait at least 30 minutes after vigerously shaking to do your initial reading on the 3/27 test. Of course drop out may start to occur much sooner.

You can reprocess your biodiesel to achieve a more complete reaction. If you have not washed your biodiesel I would reprocess with 1g NaOH mixed into 30 ml methanol per litre of biodiesel being reprocessed. Make sure to remove the glycerine layer before reprocessing.


If you have Na present it will probably be soap

Because of the presence of methanol in your biodiesel you will not know what the viscosity of the biodiesel actually is is until it is washed and dried. If you are using canola and you make biodiesel that passes the 3/27 test the viscosity will be OK too.
 
Registered: October 13, 2010Reply With QuoteReport This Post
Member
posted Hide Post
Hi all,
Reprocessed Bio,
Used Wet bottle to reprocess biodiesel(my bad).
Ingredients: Smile approx 2 ltr biodiesel, 5 g Naoh, my two 27/3 tests + 20 ml methanol on top.Dissolved Naoh, Mixed, get something.

Imagebiodiesel-reprocessed.gif (42 Kb, 23 downloads)
 
Registered: August 14, 2012Reply With QuoteReport This Post
Member
posted Hide Post
Hi all
Because initially used oil was not dewatered, after reprocessing(water presence in Oil as well becaiuse wet bottle) I suspect water stopped little bit
transesterification reaction and the stopping point might be at the
monoglyceride stage which unfortunatelly undetectable with 3/27 test. BTW 3/27 pass - no drops at all. No triglycerides.
Just look at the picture pls and comment. I think it's not a soap. I think it's long chain monoglycerides, possibly glycerol monostearate.Initial test show neutral PH on this stuff.Will do SEM EDX to be absolutelly sure there is no Na , Mg or Ca elements presence in this white stuff.
Update:
Done EDX,
Na - 2,7% by weight
C - 87.2% by weight
O - 10.1% by weight
It is a soap.

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

Imagewhite-stuff.gif (47 Kb, 15 downloads)
 
Registered: August 14, 2012Reply With QuoteReport This Post



Member
posted Hide Post
White stuff SEM EDX Analysis by weight:
C-87.2%
O-10.1%
Na- 2.7%
Soap.
Comparison to a Dove solid soap:
Na- 5.5%
 
Registered: August 14, 2012Reply With QuoteReport This Post
Member
posted Hide Post
If you're looking for elemental (or any other) comparison to typical soap, don't use Dove. Dove is soaplike, but is actually a mixture of various stuff (mostly sodium lauroyl or cocoyl isethionate and free "stearic" C16-18 fatty acid) plus byproducts of same.
 
Location: Bronx, NY | Registered: September 26, 2013Reply With QuoteReport This Post
Member
posted Hide Post
Because of the intermittent and fragmented traffic here, I'll ask this question that I also asked in another section: Why is there a substantial amount of saponifiable material left in the glycerol fraction from biodiesel mfg.? Why is there so much left after transesterif'n, and more puzzling, why does so much of it partition into the more polar glycerl + methanol phase?
 
Location: Bronx, NY | Registered: September 26, 2013Reply With QuoteReport This Post
  Powered by Social Strata  
 

Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Biodiesel Quality    complete transesterefication

© Maui Green Energy 2000 - 2014