Why cellulosic ethanol is better than corn ethanol

In recent debates with energy policies, fuel has become and increasing problem for policy makers. The decisions to switch from gasoline to alternative fuels has lead officials to asses different alternatives, one being the use of ethnol. In the last decade the use of corn ethnol as an clean burning fuel has been thought of as the optimal source in creating environmental efficientcy by providing cleaner burning fuel. However, a new form of ethanol has come to emerge as the sole provider of cleaner burning fuel. Is this alternative a better solution?
In assessing whether or not biofuel saves more energy in the complete process of creating energy we must first take a look at the cultivation of the vvarious crops taht can be used to produce fuel. Fuel that uses the more traditional approtach by way of corn may yeild only marginal renewalbe envergy retruns, while ehtanol obtained from cellulose (a technology that uses fibours materials such as wood chips, or farm residues) has a clear advantage. The biggest reason cellulosic ehtano has a better energy balance than corn is that the whole plant can be used within the fuel proces. The fermentable compoonenet( is sperarated from the nonfermentable component(lignin) which yields a high energy value.
On the flip side, large scale ehtonol production rasies other envronmental concerns, the biggest being air quality. The low blends predominantly used today have higher evaporatiotvie emissions than regular gasoline in warmer climates which contributes to ozone problems. A solution to this problem could be to use ethanol in high blends.
Today ethanol is only used as a fuel additive to help it burn cleaner. The question now is how quickly can we make the transition to using ethanol as an alternative fuel as aopposed to jsut an additive?