As an alternative fuel produced from biomass, EEI-produced butanol will be based on “green” carbon, and will thereby reduce greenhouse gas emissions. Also when burned, it produces no Sox or Nox, thereby yielding additional significant environmental benefit. Of course the same can be said for ethanol produced from biomass
From that site. I am not a chemist, but what I think i read somehwere is since this carbon came from plants, it can be reabsorbed by the plant and use as the food source.