Hydrogen powered cars won't catch on because the catalytic converters consist of platinum, which is in short supply, the hydrogen emissions are damaging to the ozone layer, plus the hydrogen emissions are light enough in weight and density to pass through the fractured ozone layer and into space, making the entire process non-sustainable.
Ethanol's net energy gain is actually an energy loss because more energy is being used in the fermenting and refining of ethanol than that which is gained from it.
peanut oil, if we can use i to make plastic, we should be able to make a car run off of it... oh wait, humanity already has!!! easier to grow than corn, and in perspective, it is not as widely consumed so replacing corn based ethanol with peanut oil should alleviate the food market problems.
speaking from a biochemical perspective, lactose contains more potential energy than ethanol anyway, so if biofuels are the way of the future, I'd say milk is in.
GATHER your cows, goats, llamas, mothers, sisters, and girlfriends and start refining milk NOW!!!
Then make a car that takes in air, purifies it, and puts it back out and uses it again. If possible.
you mean replicate photosynthesis inside an engine?