Runnng cars on ethanol is nothing new, Henry Ford originally designed the Model T run on ethanol or petrol until the prices of Petrol came to a point where it became the dominant road fuel! The fuel is obtained by distilling crops like corn, maize or wheat. The Brazillians have been runnning cars on the stuff since the mid-1970s when economic recession forced them to develop production from the country's abundant sugar-cane crops.
Although it produces carbon dioxide, it's a much less polluting fuel than petrol and burns more completely. Unfortunately, you can't just pour it into a standard petrol car without modification, but that's not the problem. Some firms can supply a black box which changes the pulse rate of the injectors and adjusts the ignition timing to suit the different fuel.
It is not quite as easy to brew up at home as biodiesel, but it is possible and the process is much like making whisky.
