The best you can get from a still is E95 because 95% ethanol and 5% water is the azeotrope of water and ethanol and so has the lowest boiling point. Also, a pot still ain't gonna make E95 with the first run. You would need to distill several times. A reflux column still can make E95 in one distillation though. And you would need to get permission from the feds to run your still, even if it just for fuel.
Eric
Well, actually, that's true brandy or moonshine pot stills.
One of the nuances to how fuel ethanol is made is that the stills are constructed differently. Fuel ethanol still design is set up for a continuous 24x7 distillation production, not pot by pot. With the that construction, you get 100% ethanol out of the still, which is promptly blended some gasoline to keep it anhydrous, (plus making it non-potable), and stable, as you are correct it would otherwise absorb water to a 5% water/95% ethanol azeotrope.
Permission from the Feds is de minimus if the annual still production is under 10,000 gallons.
There are lots of extras details for how to hydrate the cornflour and enzyme pretreatments to get all of the starch solublized, micronutrients, fermentation accelerators, choices for yeasts, and target ethanol concentration. For the still getting the fermented corn liquor (beer) degassed by removing the CO2 before it gets to the still, and for stripping the spent bottoms, evaporating the bottoms to strip off the water to go back to the beginning to add to the corn flour, and to take the solids out as wet distiller's grain solids, dried distiller's grain solids for animal feeds. On a small scale, having a plan for side stepping the evaporation process can save a chunk of energy and complexity.
If you have an interest, most ethanol plants run tours, and take an interest in visitors.
I'm not suggesting anyone shouldn't try, but I would suggest doing some research into the details. These days, it isn't exactly "uncle Bob's still" up the draw somewhere.
All the best,
Peter