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2 hour later, methanol still not clear drop out is 11.6 ml or 16% more than the oil I started with. I'll let it sit overnight and see what happens then I will repeat the test.
Ronny could be the titration of the oil, mine T's at 13 NaOH.


" 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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KieranC I do understand the chemistry involved and your explanation is too simplistic. You say that the 3/27 test works because unconverted oil does not dissolve in methanol. In fact the reality is that at 20°C methyl esters dissolve almost completely in methanol, monoglycerides partially dissolve , diglycerides slightly dissolve in methanol and triglycerides hardly dissolve at all. How little tryglyerides dissolve in methanol will depend on several factors including FFA content.
Adding 15% veg oil to well converted biodiesel is just not the same as 85% converted biodiesel.

I dont want to get off topic but Im a little alarmed at your statement " all that is required is for water washed biodiesel to be clear and bright". This is simply wrong and has been proven to be wrong many times over the years. Clear and bright biodiesel@ 20°C can contain up to 1000ppm of water,considerably more at warmer temperatures. This is double the maximum permitted level for Uk and Irish diesel fuel and more than treble the maximum permitted level in Germany. This level of water in biodiesel will cause damage to injection systems, particularly but not exclusively high pressure diesel systems.

This message has been edited. Last edited by: imakebiodiesel,
 
Location: Lismore Ireland | Registered: November 25, 2007Reply With QuoteReport This Post
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[QUOTE]Originally posted by Kieran C.:

I do not test my biodiesel for water or soap. I frequently use the 3/27 test. All that is required for water washed biodiesel is bright and clear.
------------------------------------------------
Kieran C, Like IMB I was a little alarmed at your statement,it reads as if you don't bother to dry it before pouring it into your tank. Now I see you mean clear and bright before performing
27/3.

As Ronny and I have found,adding new oil to biodiesel results in approx twice the dropout expected.

Biodiesel with added oil does not behave like partially converted biodiesel. If the two behaved the same we would have to assume that the dropout on our partially converted bio was roughly 50/50 oil/bio!
 
Location: YORK UK | Registered: April 27, 2014Reply With QuoteReport This Post
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[quote]If the two behaved the same we would have to assume that the dropout on our partially converted bio was roughly 50/50 oil/bio!
Yes, that is what the testing is showing.
It makes sense to me. Triglycerides and methylesters have more of an affinity to each other than they do to methanol.
It is only logical that a portion of the biodiesel would stay with the triglycerides and a portion would stay with the methanol.

The bright side is that your biodiesel is actually higher conversion than you thought it is.

Kieran C, No,that is not what the test is showing.

For instance,if I had 1.0mls residue in my tube (10/90)and I re-processed using 1/2 the chemical I should have done to get a complete reaction I will have approx 0.5mls residue on the re-test.

What is in the bottom of my tube is all oil. It only seems to upset the balance when tri's are added to the mix.
 
Location: YORK UK | Registered: April 27, 2014Reply With QuoteReport This Post
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Originally posted by Kieran C
quote:
I know some people think there must be something different between the triglycerides remaining in the biodiesel that have gone through the reaction procedure and triglycerides added after the reaction.
There is no difference, a triglyceride is a triglyceride.


Hi Kieran, thats correct, and the dropout at the bottom of your tube is approx 50/50 tri's/FAME Where as at the bottom of my tube it's all tri's.
 
Location: YORK UK | Registered: April 27, 2014Reply With QuoteReport This Post
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Hi Kieran,
You are incorrect in your assumption that the dropout in the tube from bio being processed contains a high proportion of methyl esters.It may contain some but nothing like the approx 50/50 amount that seems to be the case when oil is added to converted or partially converted bio.
For some reason doing this seems to upset the balance of the mix. I have also done this and had virtually the same result as yourself and Ronny. However just because this happens you cannot assume the proportions of dropout from bio "as processed" are similar.
If for instance I have 1ml dropout in my 10/90 test and I add only 80% of the chemical as calculated for the next reaction, I will still be left with a small amount of dropout on the next test.
Now according to your theory we would have no dropout at all,this just doesn't happen.
I totally agree with IMB on this point, just because adding oil to bio creates a dropout mix that is @ a 50/50 tri's/bio interesting though it is, you cannot assume the dropout from bio "as processed" is composed of the same proportions.
 
Location: YORK UK | Registered: April 27, 2014Reply With QuoteReport This Post



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It is important, when analyzing GC results to understand the limits of the method used.

If ASTM D6584 is the GC method used, the calibrated ranges for bound glycerin (mono's di's and tri's is quite small. This means that quantified results for "low conversion" fuel can be very misleading, particularly for this type of fall-out analysis. A result of 15% for triglycerides would be well outside the calibrated range for this method.

If a mass spec or different GC method is used, then the results can be valid - but it's important to understand the valid range for the method used. Just sayin' Smile

This message has been edited. Last edited by: The Trouts,


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Location: Moncure, North Carolina | Registered: April 21, 2001Reply With QuoteReport This Post
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The Conversion/ Glycerides graph I have in front of me shows that for a conversion of 83% you can expect to have about 4% monoglycerides, 6% diglycerides and 7% Triglycerides by weight.
 
Registered: July 29, 2011Reply With QuoteReport This Post
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Kieran C
Check your PM
 
Registered: July 29, 2011Reply With QuoteReport This Post
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Hi all. Thanks for the entertainment and the data. could you share the link for the graph I would be interested in that. Thanks to every body for the time and effort that has gone into the testing.
 
Location: Johannesburg South Africa | Registered: October 09, 2012Reply With QuoteReport This Post
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