I just saw a comment under a youtube video that mentioned making ethanol at home. I was looking and I found information that you can make ethanol at home by fermenting starches.
Out of curiosity I googled to see if dead leaves that fall on the ground in the fall have any starch in them.
I found this old article that seems to indicate dead leaves might be ten percent starch.
I found this page talking about much dead leaves weigh.
They estimate 22lbs of dead leaves per thousand square feet.
So possibly you might get 2 lbs of starch per thousand square feet of leaf covered ground.
I also found this page, talking about making ethanol from corn.
It says a bushel of corn would yield 31.5lbs of starch or 2.8 gal of fuel ethanol. So it seems that 31.5 lb of starch must be able to make 2.8 gal of fuel ethanol.
So 11.25 lbs of starch must make 1 gallon of fuel ethanol.
So being conservative, maybe we could say 16lbs of starch from dead leaves might yield a gallon of fuel ethanol.
This would be equivalent to the leaves covering 8,000 square feet.
This is 0.18 acres to get one gallon of fuel ethanol.
I know this is not very much, but given the vast amount of dead leaves in the fall, I wonder if someone could find an economical use for the leaves? The raw material is something that most people are actively trying to get rid of. There are plenty of landscaping companies that are getting paid to haul leaves away from peoples' yards.
I wonder if there is a way to get some use from all those leaves?