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CELLULOSIC FUELS—BETTER THAN A LOT OF CORN
TODAY’S ETHANOL is a lot of corn. Producing a motor fuel from corn grain raises the price of food. Ethanol-enhanced gasoline isn’t compatible with all cars (and other equipment fueled by it). And, overall, corn-based ethanol’s well-to-wheel tradeoffs in emissions, energy, water and operation aren’t necessarily favorable. See http://wp.me/p2ETap-2t4 for well-to-wheel analyses; for reference to these other aspects of food and compatibility, see http://wp.me/p2ETap-1eK.
However, cellulosic biofuels are no corn. They’re the real thing.
Unlike today’s ethanol, a cellulosic fuel is derived from corn “stover,” the leftover stalks, leaves and cobs of corn. Stover is inedible to humans and makes up 50 percent of harvested corn, but it can be transformed into biofuel.
The Union of Concerned Scientists website offered an interesting article on this in “5 Things I Learned in Iowa about Biofuels,” by Jeremy Martin, senior scientist, Clean Vehicles (http://goo.gl/GleYSu). Here are Martin’s five points, together with related matters gleaned from other sources.
1. Cellulosic technology has matured from laboratory bench to pilot plant to commercial processing. The stover’s cellulosic walls are notoriously difficult to decompose into usable products, but biorefineries are evolving to meet the challenge.
Dupont scientist Andy Heggenstaller knows his way around corn stover. Image from Jeremy Martin article.
2. “Lots of corn = Lots of biomass,” writes Martin. For example, Iowa grows more corn than all but three countries in the world. Part of the stover is best left behind to enrich the soil, but there would still be enough for billions of gallons of biofuel without using a single kernel of corn.
Erosion in depleted soil after a heavy rain in western Iowa, 2013. Image from Jeremy Martin article.
3. “…Yet lots of corn = Lots of problems,” Martin warns. Iowa is 90-percent farmland, but with essentially only two crops, corn and soybeans. Specialization of this kind can exhaust the land, leading to soil erosion and fertilizer runoff. These in turn contribute to water pollution in Iowa and downstream in the Gulf of Mexico.
4. Sustainable farming practices are crucial. Martin cites Iowa State University and companies like AgSolver as leading the way in studies.
5. Perennial crops have a major role. For example, perennial grasses are highly productive sources of cellulosic mass. Planting these instead of corn can make economic sense as well as lessening crop specialization.
Cover crop of cereal rye planted in corn stubble enriches the soil. Image from Jeremy Martin article.
Martin cites research results of STRIPS, the Science-based Trials of Row-crops Integrated with Prairie Strips. Perennials, in as little as 10 percent in narrow patches along contours and slopes, can reduce soil erosion and fertilizer runoff by 85 to 95 percent.
In other cellulosic news, U.S. chemical giant Dupont and Ethanol Europe Renewables Ltd. have signed a Memorandum of Understanding with the Republic of Macedonia. The aim is a Macedonia Cellulosic Project culminating in production by 2018. See http://goo.gl/eC1QbD.
Closer to home than this southeastern European deal, Abengoa SA’s first facility for producing cellulosic ethanol is in Hugoton, Kansas. Abengoa, based in Seville, Spain, is Europe’s largest producer of ethanol. The Kansas plant, which began production last month, can make as much as 25 million gallons of cellulosic ethanol a year. See http://goo.gl/J4acHO.
In truth, these efforts are only a start. To put them in perspective, the U.S. Energy Information Agency cites U.S. consumption of transportation fuel at around 13 million barrels (546 million gallons) per day. ds
© Dennis Simanaitis, SimanaitisSays.com, 2014
Simanaitis Says 
Very interesting idea, but somehow it still takes a lot of energy to grow the corn, transport the stover to ethanol plants and make ethanol out of it. What would the net benefit be everything taken into account? Would we get 80% back as far as usable energy is concerned, or…? And what if it were organically grown? Somewhat less of course…. But it would be even cleaner still. Our Earth desperately needs alternative and environmentally friendly fuels so any good suggestions need and deserve to be taken seriously.