This will never happen. There is no way that governments will allow individuals to produce pure ethanol as the potential tax and duty losses will be astronomical. Let's see: I will produce 10 gallons ethanol for my car. 9 1/2 gallons go in the gas tank and 1/2 gallon goes behind the bar for later.
The production of ethanol or ethyl alcohol is extremely tightly controlled. Allowing individuals to do this in their back yards will be out of the question.
People also seem to completely ignore supply and demand. If even a small percentage of the population begins to run their cars on 100% ethanol, the price of sugar will go through the roof just as corn and other grains are doing now.
Wayne