I'm pretty sure that by now most readers of this site can explain the difference between ethanol made from grains like corn and cellulosic ethanol. But, here is a nice article from What's Next Network that explains some of the differences and what it takes to get more ethanol from corn using a cellulosic process. The process described simply uses water to pretreat the biomass, corn in this instance.
Of course, this would not solve the perceived problem of using corn, a food source, for fuel production. What it would do, however, is extract more fuel from the corn that is currently being used to generate fuel, meaning that either the amount of corn being used for fuel could be reduced, or more likely, additional ethanol could be generated from the current amount of corn being used for fuel... 'cause there's lots of money to be made from selling the fuel. Make sense?
[Source: What's Next Network]