Posted on 08/21/2008 6:46:23 AM PDT by Red Badger
Calculated bioethanol yield per hectare.
A study by Agricultural Research Service (ARS) scientists found that sweet potatoes grown in Maryland and Alabama, and tropical cassava grown in Alabama, yielded between two to three times as much carbohydrate (starch, sucrose, glucose) for fuel ethanol production via fermentation as field corn grown in those states.
Dr. Lew Ziska, a plant physiologist at the ARS Crop Systems and Global Change Laboratory in Beltsville, Md., and colleagues at Beltsville and at the ARS National Soil Dynamics Laboratory in Auburn, Ala., performed the study. The research is unique in comparing the root crops to corn, and in growing all three crops simultaneously in two different regions of the country.
Relative to carbohydrate production from corn in each location, sweet potato and cassava yielded approximately 2.8x and 2.9x respectively as much carbohydrate as corn in Alabama; 2.3x and 0.5x respectively for the Maryland site. For sweet potato, overall carbohydrate production was 9.4 and 12.7 Mt Ha-1 for the Alabama and Maryland sites, respectively. For cassava, carbohydrate production in Maryland was poor, yielding only 2.9 Mt Ha-1. However, in Alabama, carbohydrate production from cassava averaged ~10 Mt Ha-1.
Averaged for both locations, sweet potato yielded the highest concentration of root carbohydrate (ca 80%), primarily in the form of starch (ca 50%) and sucrose (ca 30%); whereas cassava had root carbohydrate concentrations of (ca 55%), almost entirely as starch.
Sugarcane, which contains 10-15% sucrose, can produce 8 to 12 Mt of carbohydrate Ha-1; corn contains 60-65% starch and produces between 7 to 10 Mt carbohydrate Ha-1.
Yet, because sucrose is easier to convert to ethanol than starch, actual bioethanol yields are approximately 6.4 to 9.6 and 2.0 to 2.8 m3 Ha-1 for sugarcane and corn, respectively. Assuming a similar conversion efficiency for corn and cassava, cassava grown in Maryland would not be competitive with either corn or sugarcane. For cassava grown in Alabama however, bioethanol yields would be approximately 4.0 m3 Ha-1 which is comparable to corn bioethanol production in this region. Interestingly, because of the greater sucrose yields for sweet potato relative to cassava, bioethanol production would be 5.2 m3 Ha-1 in Alabama (3 and 2.2 m3 Ha-1 from sucrose and starch); and, 6.4 m3 Ha-1 in Maryland (3 and 3.5 m3 Ha-1 from sucrose and starch). For sweet potato, these potential yields of bioethanol are more than double estimates of bioethanol from corn at each location and are approaching the lower limits of sugarcane production. —Ziska et al. (2008)
The disadvantages to cassava and sweet potato are higher start-up costs due primarily to increased labor at planting and harvesting times. If economical harvesting and processing techniques could be developed, the data suggests that sweet potato in Maryland and sweet potato and cassava in Alabama have greater potential than corn as ethanol sources, according to the researchers.
Further studies are needed to get data on inputs of fertilizer, water, pesticides and estimates of energy efficiency. Overall, the data indicate it would be worthwhile to start pilot programs to study growing cassava and sweet potato for ethanol, especially on marginal lands.
A separate study by Ziska and colleagues also found that wild kudzu—an aggressive vine species imported from Asia to control soil erosion—stands in Alabama and Georgia could produce 5 to 10 tons of carbohydrate per hectare, which would rival carbohydrate production from corn and sugar cane fields, but without the costs associated with planting, fertilizer and pesticides. This would rival carbohydrate production from corn and sugar cane fields, but without the costs associated with planting, fertilizer and pesticides.
ARS is a scientific research agency within the US Department of Agriculture.
Resources
Lewis H. Ziska, G. Brett Runion, Martha Tomecek, Stephen A. Prior, H. Allen Torbet, and Richard Sicher (2008) A geographical evaluation of root-crops as potential carbohydrate sources for bioethanol production.
Lets burn Democrats for fuel instead...
Led my Chevy to the field, but tanks were dry...
Just how much more starch should most Americans have in their diets?
our cars will all be diabetic hybrids.............
A separate study by Ziska and colleagues also found that wild kudzu...
That plant is plague on many places of this nation.
Try this:
Them good ol’ boys drivin’ on whisky and rye,
This will be the day those plants die.
I’m sorry, your pellet burning stove has been declared “forbidden contraband”. It emits too much CO2 and must be destroyed in order to “save the planet” fro Global Warming. The Official Federal Disposers will be by first thing in the morning to confiscate, er, dispose of it....
I hope I hope I hope..Its KUDZU..I might be rich..got acres of the stuff...
“The disadvantages to cassava and sweet potato are higher start-up costs due primarily to increased labor at planting and harvesting times.”
We don’t need labor intensive fuel production, which would be more stoop labor in the fields. And where might such labor come from? I’m sure any corporation producing fuel from root crops would want the cheapest labor possible.
“A separate study by Ziska and colleagues also found that wild kudzu—an aggressive vine species imported from Asia to control soil erosion—stands in Alabama and Georgia could produce 5 to 10 tons of carbohydrate per hectare, which would rival carbohydrate production from corn and sugar cane...”
Might be a good possibility, and would be a machinery intensive crop, harvested about like hay for which it has been used.
I couldn’t agree more.This MisUse of out food supply is nothing more than a “payback”to Cargill,Archer,Daniels,Midland,and The Enviro-Wackos!The production of ethanol is actually far more environmentally than the production of oil,coal,etc. inasmuch as it requires enormous quantities of water,corn,etc.,and then it has to be transported to the refineries for blending(rather than be piped).Also,it “weakens”the power of gasoline making it less efficient.ALL of rhese problems(high fuel-prices,high food-prices and the resulting inflation)were created for us by The DemonRats!!
Kudzu, LOL! Brilliant!
What an awful graph. Where’s algae? Where’s jatropha?
I’m sorry, your pellet burning stove has been declared “forbidden contraband”
I do not have a pellet burning stove, I was just suggesting a way to burn food. I use an old non EPA stove that smokes a lot. I an doing my part to stop the comming Ice Age.
Are those used to create ethanol?
Silly scientists, thinking that ethanol fuel is about “energy yield” or “gallons per acre” or any other quantifiable scientific parameter:
It’s all about farm subsidies for Iowa, the first state to have a presidential “caucus” - why else would the subsidies be for corn???
Congress doesn’t want subsidies for Alabama, currently a solid GOP state in Presidential elections!
I think they were concentrating on crops that can be grown in the latitudes of the main US. ......
Does anyone have any research results on switchgrass or cellulosic ethanol that they could send to these food-burning whackos?
Maryland “Freak State” PING!
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.