Funny thing is I've been running both fuels in my car for as long as it's been around ( 20 years maybe ) and the only thing I've had any problems with is the hose coming off of the fuel pump. That hose never seems to last long anyway. I have seen no effects on anything we run including tractors, lawn mowers, cars, trucks and weed trimmers. I think maximum is 10% here and more than that could cause problems. So, if it really is a problem, why haven't I seen it?
Field corn that is largely used as animal feed is the same corn used to make ethanol. After the starch in the corn is used as part of ethanol production the remainder DDG's ( dried distiller's grains ) is fed to animals; usually cattle. Part of the fermentation process releases carbon dioxide which is captured and used in the soft drink industry so nothing goes to waste. Many operations now include green houses which use the waste heat from fermentation and the CO2 to enhance plant growth.