First off, ALL plants "capture carbon" (seriously, you're an eco zealot to use such stupid language). Not a feature. Secondly...
I make ethyl alcohol from corn all the time. That "Ethanol" is now synonymous with ethyl alcohol is more eco-faggot bullshit. What is the gas mixture you put in your car? Now "Ethanol" is completely synonymous with a real organic compound in actual chemistry. Nice way to play with language and fuck actual science with your bullshit religion. But, thanks to turning me on to this travesty of leftist bullshit. I had not even realized how far this has gone with you morons till seeing how fucked up the Wikipedia page actually is. Friedrich Wohler is rolling over in his grave with your fake, religious bullshit.
While I throw out the trub and spent grains there is ZERO corn oil made from refining and distilling corn. It is possible to wetmill the corn first, but no one except the most gigantic ethanol operations could afford it. That is not where most corn oil comes from, and maybe not fit for human consumption. Now, the spent grains could probably be dried and fed to cattle, but when all the starch has been removed and catalyzed into sugar for conversion to alcohol it would be very nutrient/calorie poor, and nothing like normal cattle feed. Much more likely it could be used as a filler in some other animal feed, but again, how many ethanol operations do that? My guess is very few. You have to be an Anheuser Bush level to make any money using spent grains like that, so it isn't done, and is just an eco-acolyte talking point, because it's possible.
The only legitimate argument you make is that turning plants into alcohol is renewable, where as creating more hydrocarbons happens on a time line and scale too long to be even considered. That would be fine if we did not use 20,000 barrels of oil per day. 30% of Americas corn goes into making ethanol (mostly because of subsidies), how much cheaper would our groceries be if the price of animal feed dropped 30%?
I don't blame farmers for making money where they can make it, but ethanol is retarded, and it costs us all a lot of money!