without scrutinizing the numbers something not adding up...

this past weekend I help get someone started on making Bd in there new system. being a local 'expert' on making BD I was happy to help.
we heated the oil and mixed in the proper methanol/KOH mix for single stage.. after 1.5 hrs the batch still failed the 27/3 test. at this point I said...wait let's make this a base/base reaction or 2 stage. We did this.. at 45 minutes into the 2nd stage to passed the 27/3 test. I stopped adding BD at 9mls into 27 mls of methanol..blew away the test...but just to show some others that came later after all this was done I added a couple of drops of WVO to this mix.. fall out happend right away... so does the WVO draw methanol into it...I don't think so..if it did that would imply the vege oil and methanol mix..and we know they don't

-dkenny

When you added the WVO to your 27/3 test vessel, there was no catalyst mixed in with the methanol therefore the immediate dropout of oil.

When you add glycerol to your WVO both the catalyst and the methanol are present for a partial reaction.

Is anybody still trying 5%wash water glycerin treatment? I've been doing it, and had no idea this thread and discussion existed.

My first couple of batches went ok, but around the third and 4th batch I encountered a ton of FOAM following methanol recovery from the finished BD. I use a centrifuge to spin out soaps and any residual glycerin. I had foam coming out of the the tank and spilling onto the garage floor.

I have assumed that this is excess soap in water. I could be wrong, it could be excess soap being carried in methanol I guess. I use vacuum recovery to remove the methanol, but there is always some still left which I drive off by spray circulating in an open top tank. Lately I have been rushing that step and running the centrifuge at the same time. Its possible that with some methanol still in the batch, the centrifuge agitation was making suds from soaps.

I've done 2 things to stop the foaming soaps, but have not isolated which one is working yet. I have reduced my catalyst. I use NaOH. I used to titrate at 1-1.5 so would use 6-6.5 g/l. I've now dropped it to 3.8-4 g/l. I am using about 15 gallons of glycerin to treat 55 gallons of WVO (which is brite and clear with trace water to start). The other thing I have started doing is to distill/dewater after settling and draining the glycerin pretreatment overnight. If my WVO is picking up water, this step takes it back out prior to reacting. I guess it would also remove the methanol picked up during the glycerin pretreatment though.

Anybody else still working with this method?

Jon,

I have never tried the glycerol pretreatment of WVO with water added to the glycerol. It seems to me that you should use the driest glycerol that you have, so that it can suck up any resididual water in the WVO during the pretreatment thus giving you a drier product to convert to BD.

I am sure there is an amount of moisture in the pretreatment phase that will work, just not something I would want to try to figure out.