Green Fuels Promise Carbon-Neutral Combustion Now

摘要

BIOFUELS: Using green energy to make fuel from plants that pulled CO_2 out of the atmosphere theoretically adds no new CO_2 to our "greenhouse." But running on pure ethanol made from corn doesn't usually count, because the land used to grow that corn has typically been converting the same amount of CO_2 whether it became fuel or corn syrup, resulting in no net carbon reduction. Biofuels made from cellulosic feed stocks like corn stalks, miscanthus grass, or new crops planted where nothing has been or could be grown before do count, and there are numerous processes for converting cellulosic materials or even trash to ethanol, methanol, or butanol. There are also several algae-to-biodiesel processes identified. Sadly, they're all too costly to compete with cheap gasoline.