Butanol can't be produced in a normal ethanol plant so that's the first error in the quoted info. In ABE fermentation, there is a self limiting toxicity inhibition that hasn't yet been overcome. Secondly, the inevitable cogeners such as butyric acid would prevent most sane communities from supporting butanol production nearby. Really, one encounter with that one will erase any lust for profits from biobutanol. Do it on an pty stomach. spec