Having completed my version of the Imisides method;
http://www.biopowered.co.uk/forum/index.php/topic,3039.0.htmlI was amazed at the amount of emulsified mono glycerides produced when water washing. I'm sure the reason is the ambient temperature processing using this method.
I normally process S1 at ambient but then use heat for S2, simply to reduce this problem. Also I added exactly the correct amount of chemicals as indicated by the 10/90 results for S2 using the Imisides method, so as per the original instructions a good overdose of chemicals is probably reqd when reacting at ambient. (Mark Imisides uses 15gms KOH/litre of oil)
I did another process at the weekend (not Imisides) 10/90 after S1 showed 0.6mls, so on a 200 litre batch size the normal KOH amount would be about 90gms for S2. I added 120gms of KOH and 150mls of ASM and processed S2 at 55degs for 1 hour. Virtually no mono's showed, in fact this was one of the easiest batches I have ever water washed.
Just a few added words here to add a little logic to the above;
Monoglycerides are always present in biodiesel.
They are soluble in methanol, so even with a clear 10/90 they will still be present.
The way to reduce them seems to be to use an overdose of chemicals on S2, which must be done at temperature.
The only way they can be made 'visible' is during a hard water wash when they will emulsify with some of the water and then can be removed.
Their presence in the fuel will reduce the volatility of the fuel, but in practise this does not seem to make any notable difference.
Their presence in the fuel will increase the temperature at which the fuel will mist and gel.
