Two-stage biodiesel reaction

[Ivan]

Anyone tried this? It's supposed to improve the rate of conversion of poor quality oils (high FFA content), into biodiesel.

I have some really poor stuff available (one has a titration of 80!! and the other around 18). The 80 oil looks bad, but the one that titrates at 18 looks good and clean. Both are semi-solid, so perhaps this is adversely affecting the titration somehow? I wondered whether the two-stage reaction might give a good enough yield to make it worthwhile converting these oils.

[Chug]

I tried it once a few years back when I first started making BD but my oil is usually low use/titration so I didn't benefit anymore over the single stage method, but those who have high use/titration oil claim better yield using this recipe from the Collaborative Biodiesel Tutorial (CBT)
here
http://biodieselcommunity.org/basebase/

Chug

[Ivan]

Thanks Chug,

I hadn't seen that one before. Looks interesting - I might give that a go - seems very little effort.

I was thinking more along the lines of the acid/base procedure which is supposed to convert the FFA to FAME as well as the triglyceride.  High titration oils  are full of FFA (I reckon higher than 40%) - so in theory, yields could approach a low-titration oil if you use acid/base reaction. That's the theory, but I wonder if it works as well as that in practice?

I think my phenolphthalein has gone off - I accidentally left it on the windowsill, and it doesn't seem to work any more   

[Chug]

Acid esterification methods
http://biodiesel.infopop.cc/eve/forums/a/tpc/f/629605551/m/210108388

Titration with turmeric is cheap, easy to obtain and non toxic all of which phenolpthalein isn't
http://www.biodieselcommunity.org/turmeric/

Chug

[Ivan]

Thanks Chug,

Very interesting comments - most people seem to think the classic two stage reaction is very unreliable.

I was wondering about the tumeric indicator. I'll give it a go over the weekend