One of the side reactions (unwanted) that we have going on is the -
Acid + Base >> Salt + Water
reaction. Its often called a "neutralisation" reaction.
Its why FFAs (free fatty acids) are the problem - not only do they take out the base (which would only be a catalyst in our main transesterification reaction - ie not used / taken out), but also the reaction itself creates water, which further goes on to mess things up in the second unwanted reaction - the saponification reaction (the one that makes soap)
I just had an idea - i have not thought about it that much, but here goes -
Hot oil can be dried by bulbing / spray bars etc.
Once the methoxide is added, this is when the neutralisation reaction would normally occur - but the oil cant be dried with air then, as the methanol would be lost.
What about separating the neutralisation reaction?
Say, for example, having a setup where the oil is heated, bubbled / sprayed or whatever, but, once hot and dry, a recirculating system can be added, where the oil is pumped through a canister of captive base?
This may not work in the slightest - ive never tried it. The base may react with hot neutral oil. Or the water liberated in the neutralisation may just saponify furiously (likly, i think) and create "a right mess".
...but maybe it may be possible with a much milder base than what we usually use?
