Cellulosic feedstocks have many advantages over using corn to produce ethanol. Because cellulosic crops are not used for food, there is inherently less price volatility. And because a wide variety of crops can be used, they can be grown in a wide variety of geographic locations–even on marginal lands–and can, therefore, be more abundant. Plus, with certain crops, more ethanol can be produced per acre than can be made with corn.
With so many advantages, it seems only natural that we have dedicated energy crops, rather than using food crops for ethanol production.
Here are some numbers to think about.
Right now, corn yields, on average, about 160 bushels per acre, with industry predictions climbing all the way up to 300. And we get about three gallons of ethanol per bushel. That means for every acre of corn harvested, about 900 gallons of ethanol can be made.
Add in four tons of stover (converted cellulosically) per acre, with which you can produce 100 gallons per ton, and we’re looking at additional ethanol production of 400 gallons per acre–for a grand total of 1,300 gallons per acre. And that’s using two different feedstocks, with two different harvest times, two different costs and two different conversion processes.
Now consider a dedicated biomass energy crop like switchgrass, miscanthus or sorghum. These crops can be harvested, at the present time, at a rate of 20 tons per acre(very high estimate), with ethanol production of 100 gallons per ton(very advanced technology), for a total of 2,000 gallons per acre. You can see why energy crops and the cellulosic process will be huge successes.
And that’s with the current numbers. Imagine how big this would be if crop yields and gallons per acre were increased and cost were continually driven down. That’s exactly where this industry is heading.