[edsheppa]

So, you think you have a bushel of corn, you make ethanol from it and you still have a bushel or corn? That's what "coproduct" means. And it's not what happens.

[Keith in Iowa]

You didn't read anything at that last link I provided, did you? If you had, you would not be making such an ill-informed comment.

And...

co·prod·uct n. A product produced together with another product.

Ethanol is but 1 coproduct of the process of making ethanol.