The Second Coming of Biofuels

Plant-based fuels have been a big disappointment to date, but new “green biofuels” might fulfill their promise.

As an eco-conscious citizen, I should be a little ashamed of my attachment to pistons and gears. But in this test drive, I don’t have to be. While the Audi I’m test-driving is a regular production car, the fuel inside it is a new, ultra-potent kind of biofuel that has only a quarter of the per-gallon carbon footprint of petroleum-derived fuel. Sure, that doesn’t sound that exciting compared to a zero-emission electric car

The New Plant Fuel
“Green diesel,” as it’s being called, isn’t the first effort to use plants to power cars; your gas tank probably has a blend of gas and plant-derived ethanol inside it right now. But it’s hard to get excited about biofuels when they already have such a bad rep. The use of corn and sugar in fuels has driven up the cost of food by a whopping 75 percent worldwide, according to a recent report by the World Bank. And a Nobel-prize winning chemist has publicized his findings that biofuels made from nitrogen-thirsty plants (like corn and canola) actually produce a net increase in greenhouse gas emissions, because they release nitrous oxide during their production. As if all that wasn’t bad enough, ethanol blends hurt your car’s fuel economy. Not exactly the makings of a green energy panacea.

But high-performance green diesel and gas aren’t like other biofuels; they’re perfect substitutes for petroleum-derived fuels, except they’re made from plant matter like forest detritus, also known as cellulosic waste, or from algae. Green fuels can also be refined on the exact same equipment that refines petroleum. By contrast, traditional ethanol requires new equipment and uses edible plants like corn and sugar that need rich farmland to grow.

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