You mean ethanol, right? I don't think it's produced by fermentation, at least not without a secondary process that removes the other hydrocarbon. That aside,

You mean ethanol, right? I don't think it's produced by fermentation, at least not without a secondary process that removes the other hydrocarbon. That aside, yes, plant biomass to alcohol is a carbon-neutral tech that has already existed for a really long time. Let plants take carbon out of the atmosphere, ferment the starches and sugars into fuel alcohol, feed the remaining cellulose to animals, burn the fuel, eat the animals, and return most (but not all!) of the carbon back to where it came from. It's really an incredible process, but obviously its existence is a threat to the oil industry. If you've ever noticed the propaganda that ethanol is bad for engines and worse for the environment, well, just follow the money.