Switchgrass ethanol
Switchgrass, a native prairie grass, is a potential source of ethanol for powering automobiles. Ethanol, of course, is hooch. If you've ever had a "flambe" dessert or a flaming shot at the bar, you know that alcohol can combust. And if it combusts, it can drive an internal-combustion engine. Beacuse of this, ethanol has been touted as a solution to (a) the U.S. dependence on foreign oil, and (b) the U.S. dependence on oil, period. Oil's energy is ancient photosynthetic energy, but liberating it comes with a cost: CO2 is released. This is where the vast majority of anthropogenic greenhouse gases come from. So ethanol sounds like a good deal... but there's a catch.
As any homebrewer knows, to make alcohol, you have to ferment something -- usually a sugar from fruit or grain. Brazil has used sugarcane sugar to produce tons of ethanol, and they have developed an automobile fleet that can run on it. Inspired by this success, our own president announced an initiative to develop ethanol in America. We can't grow sugarcane in most of the United States, though, due to climate. But we can grow sugar beets, and we can grow corn. Boy, can we ever grow corn! So that's been the emphasis so far: grow corn, harvest the kernels, get some of that good old high-fructose corn syrup, and then ferment it into corn liquor... I mean, ethanol. There are some dark clouds hovering over this utopian fuel, however. First off, corn is food. We eat corn. We feed corn to our livestock. We put high-fructose corn syrup in EVERYTHING. So corn ethanol competes with food corn. Second, it takes a huge amount of energy to plant, fertilize, de-pestify, grow, and harvest corn. Ultimately, we do barely better than breaking even, in terms of energy invested in producing corn ethanol versus the energy we glean from it.
This is where switchgrass comes in. Because it's not food, it doesn't compete with corn for edible market share. Because it's a native plant, it's much more adapted to pests & whatnot -- it's not as "needy" a crop to grow. It doesn't need fertilizer. And because the entire plant is fermented (as opposed to just the kernels) more photosynthetic energy gets retained as fuel energy. Amazingly, all this adds up to the fact that switchgrass has the potential to yield ethanol with 540% more energy than it takes to produce it.
Both forms of ethanol have additional caveats: Regardless of source plant, it takes even more energy to ship that corn/switchgrass to the fermenting facility, and then ferment it, purify it, and ship it to fueling stations around the country. All (or most) of that energy releases more CO2 into the atmosphere. Second, these are still crops, and they need water and arable land to grow. With 6.6 billion people on Earth, we could probably stand to use that land for feeding our many hungry mouths. Third, ethanol still emits carbon when it's burned. It's modern carbon rather than ancient (fossil) carbon, but that doesn't mean a whit as far as global warming is concerned. Fourth, ethanol is only a solution for transportation -- it doesn't power my computer or my washing machine. To me, it makes more sense to invest in solar energy, and then have electric cars that run on batteries recharged on that energy. Solar can also power our homes and other energy needs. Lastly, solar doesn't need prime farmland. In fact, the collector panels are probably best positioned out in the desert, in "wasteland" we're not using for other purposes.
More information: National Geographic has a piece on switchgrass, and WIRED had it as their cover story a couple of months ago. And: Discovery news had a little blurb on the new research.
As any homebrewer knows, to make alcohol, you have to ferment something -- usually a sugar from fruit or grain. Brazil has used sugarcane sugar to produce tons of ethanol, and they have developed an automobile fleet that can run on it. Inspired by this success, our own president announced an initiative to develop ethanol in America. We can't grow sugarcane in most of the United States, though, due to climate. But we can grow sugar beets, and we can grow corn. Boy, can we ever grow corn! So that's been the emphasis so far: grow corn, harvest the kernels, get some of that good old high-fructose corn syrup, and then ferment it into corn liquor... I mean, ethanol. There are some dark clouds hovering over this utopian fuel, however. First off, corn is food. We eat corn. We feed corn to our livestock. We put high-fructose corn syrup in EVERYTHING. So corn ethanol competes with food corn. Second, it takes a huge amount of energy to plant, fertilize, de-pestify, grow, and harvest corn. Ultimately, we do barely better than breaking even, in terms of energy invested in producing corn ethanol versus the energy we glean from it.
This is where switchgrass comes in. Because it's not food, it doesn't compete with corn for edible market share. Because it's a native plant, it's much more adapted to pests & whatnot -- it's not as "needy" a crop to grow. It doesn't need fertilizer. And because the entire plant is fermented (as opposed to just the kernels) more photosynthetic energy gets retained as fuel energy. Amazingly, all this adds up to the fact that switchgrass has the potential to yield ethanol with 540% more energy than it takes to produce it.
Both forms of ethanol have additional caveats: Regardless of source plant, it takes even more energy to ship that corn/switchgrass to the fermenting facility, and then ferment it, purify it, and ship it to fueling stations around the country. All (or most) of that energy releases more CO2 into the atmosphere. Second, these are still crops, and they need water and arable land to grow. With 6.6 billion people on Earth, we could probably stand to use that land for feeding our many hungry mouths. Third, ethanol still emits carbon when it's burned. It's modern carbon rather than ancient (fossil) carbon, but that doesn't mean a whit as far as global warming is concerned. Fourth, ethanol is only a solution for transportation -- it doesn't power my computer or my washing machine. To me, it makes more sense to invest in solar energy, and then have electric cars that run on batteries recharged on that energy. Solar can also power our homes and other energy needs. Lastly, solar doesn't need prime farmland. In fact, the collector panels are probably best positioned out in the desert, in "wasteland" we're not using for other purposes.
More information: National Geographic has a piece on switchgrass, and WIRED had it as their cover story a couple of months ago. And: Discovery news had a little blurb on the new research.
Labels: ethanol, global warming, solar
