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Water generation in AE and the subsequent base stage

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November 28, 2014, 09:15 AM
Water generation in AE and the subsequent base stage

I tried some AE with my 7.5 NAOH (11 KOH) Oil.
My first batch seems to have performed well on the AE stage, finishing @

However, my base process did not pass a 3/27 test. I 'think' that maybe
my second stage had some methanol with moisture in it.

However, It made me wonder about the AE stage creating water that messes with
the base stage. Is this an issue? If I understand the AE process, as the titration
increases, acid water is drained off to reduce the T and remove water, which would inhibit
the base process.

Is this a concern for a T around 11KOH?

November 28, 2014, 11:09 AM
Yes there is water produced in the ae reaction, some of course is drained with the junk but there is also water in the remaining methanol which can affect the transesterfication process. Any water that enters this process can carry the caustic to the soap making reaction and then the T reaction is starved for caustic. I always put a couple ltrs less methanol in the ae reaction then for transesterfication I add this amount plus methanol equal to the volume of the drained junk. I found that after ae that naoH is best for transesterfication, for some reason KOH could take one or to reprocess to pass 3/27. Not a real problem since I always do a two stage transesterfication 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.
November 28, 2014, 06:57 PM
Thanks Biotom,

I was following the dkdenny procedure on the makebiodiesel site. As I understand those instructions. A t < 14, doesnt settle and drain any of the junk. Is it better to settle, drain
and replace the junk with methanol in my situation with 11KOH oil?

I didnt think to try a 2 stage base process, however, I will on my next batch.