Study: Miscanthus More Than Twice as Productive as Switchgrass for Energy Crop

www.greencarcongress.com ^ | 07/11/2007 | Staff

[Red Badger]

Miscanthus. Standing next to the grass is Dr. Emily Heaton (now with Ceres), who is 5' 4" (163 cm) tall. Source: UIUC

Researchers at the University of Illinois at Urbana-Champaign have made the first direct comparisons of the biomass productivity of two C4 perennial grasses: switchgrass (Panicum virgatum) and Miscanthus (Miscanthus x giganteus). The two have been widely trialed as low-input bioenergy crops in the US and EU, respectively.

Results from the trials throughout Illinois show that Miscanthus is more than twice as productive as switchgrass. Its efficiency of conversion of sunlight into biomass is amongst the highest ever recorded. The research team presented their results at Plant Biology and Botany 2007, a joint congress including the American Fern Society (AFS); the American Society of Plant Biologists (ASPB); the American Society of Plant Taxonomists (ASPT); and the Botanical Society of America (BSA).

The team, led by Frank Dohleman of the Plant Biology Department, theorized that Miscanthus produces more usable biomass than switchgrass because of these three key attributes:

1.

Miscanthus can gain greater amounts of photosynthetic carbon per unit of leaf area; 2.

Miscanthus has a greater leaf area; and 3.

Miscanthus has a longer growing season.

The research team measured the amount of gas exchanged on the upper canopy of Miscanthus leaves from pre-dawn to post-dusk on 20 dates in the 2005 and 2006 growing seasons. The averages from two years’ data showed that Miscanthus gained 33% more carbon than switchgrass.

Integrated measurements also showed that the Miscanthus leaf area was 45% greater than switchgrass and that Miscanthus plants grew an average of eleven days longer than switchgrass. This extended growing season and accompanying lower temperatures proved to further boost the photosynthetic activity of Miscanthus. Specifically, pyruvate Pi dikinase was found to be expressed at higher rates when ambient temperatures are lower. This enzyme supports C4 photosynthesis in Miscanthus.

The University of Illinois at Urbana-Champaign is working with the University of California at Berkeley and the Lawrence Berkeley National Laboratory in forming the new $500-million Energy Biosciences Institute (EBI) funded by BP, with UC Berkeley taking the lead. (Earlier post.)

As part of the EBI, some 340 acres of farmland at the Urbana campus will be devoted to the study and production of feedstock for biofuel production. Researchers will explore the potential benefits of using corn crop residues, switchgrass, Miscanthus and other herbaceous perennials as fuel sources. The initiative will explore how adequate supplies of high quality plant biomass can be sustainably produced and utilized in facilities that convert the biomass to fuels.

Feedstock development is one of five research areas at the EBI. The others are biomass depolymerization; fossil fuel bioprocessing (converting heavy hydrocarbons to cleaner fuels) and carbon sequestration; socio-economic systems; and biofuels production. In addition to feedstock development and socio-economic research, Illinois will work with the other research institutions on biofuels production. UC Berkeley will lead this part of the project, with Illinois joining the search for the most efficient use of microbes to harvest the energy in plants for biofuels.

Resources: “Does increased daily carbon assimilation coupled with a higher Leaf Area Index and longer growing season explain the difference in productivity between two potential bioenergy crops?”

[toast]

have you noticed the lack of insects, we are here in the midwest, no grasshoppers, bees, nothing, there are no insects left ...

Here in Minnesota we have plenty of bugs. The grasshoppers and bees are usually more numerous later in the summer. But right now we got loads of mosquitoes.

[Red Badger]

“farm animals” are not allowed in residential areas, per a COUNTY ORDINANCE. There is a current controversy going on here over a guy who has a pet chicken........

[JamesP81]

Why is that?

Given the optimal ethanol yield from corn on a per acre basis, we'd need over 400 million acres of corn to displace gasoline as a motor vehicle fuel. That constitutes over 4 times the corn acres we have planted now, and that's not considering we also use lots of corn for feed and for other foods.

Not sure what the yield per acre of this stuff is, but if it's high enough, it might be feasible.

[eraser2005]

You must not know how ungodly hot and humid central Illinois summers can be. :)

[Mr. Lucky]

The US imports the oil to refine about 87 billion gallons of gasoline per year. 400 million acres of corn would produce 179 billion gallons of ethanol.

Anything which lessons US dependence upon oil from third world hellholes, is worth a look.

[JamesP81]

The US imports the oil to refine about 87 billion gallons of gasoline per year. 400 million acres of corn would produce 179 billion gallons of ethanol.

US gasoline consumption last year was around 145 billion gallons. You'd need 1.4 times that many gallons of ethanol to equal the same energy output, giving you about 210 billion gallons of ethanol. Optimal ethanol production is 500 gallons per acre under ideal conditions. That gives you a need of over 400 million acres for fuel. That's over 4 times our corn acreage this year, and this year American farmers have planted more acres of corn than they have since 1944.

[Red Badger]

This is Florida. We have 95-95-95 weather. 95°F-95%humidity-95% chance of rain.....

[Old Professer]

From the looks of that picture, I’ll bet Dr. Harton has the same effect on men.

[Mr. Lucky]

I'm not sure why you think the US should supplant its own oil production with bio-fuels; imports from the third world appear to be the problem.

While a gallon of ethanol generates maybe 40% less heat than a gallon of gasoline, that doesn't directly correlate into 40% less mileage. Ethanol can burn more efficiently than gasoline, generating more power, making up much of the difference.

In my Silverdao 1/2 ton pickup, the mileage drop from 87 octane gasoline to 105 octane E-85 is about 15%.

[Red Badger]

...in the midwest, no grasshoppers, bees, nothing, there are no insects left ...

They've obviously all moved here, to my house.........

[Old Professer]

I fix mowers; used customer’s mowers this morning to do my backyard.

Just take the dipstick out, take off the air filter and turn it upside down in your neighbor’s driveway overnight and then put new gas and oil in it; a new spark plug and it will probably start right up tomorrow.

[Old Professer]

Weather Underground is reporting 87F and 63% humidity.

[Old Professer]

From that picture, I’d bet Dr. Harton has the same effect on men.

[dangerdoc]

Plenty of bugs here in Kansas too.

Not too many birds though.

[JamesP81]

Even if by some miracle ethanol equates gallon for gallon with gasoline (which it doesn't) that would still require dedicating 292 million acres of corn to it, which is still three times our current corn acreage.

If this grass being talked about in the article is 10x as efficient per acre, you'd still need 40 million acres of it, assuming a more realistic gallon of ethanol to gallon of gas ratio, which will have to come out of other croplands. That means permanently higher good prices. Maybe that's worth it, but 40 million acres is a hell of a bite out of our arable land and doesn't leave us with a lot of margin for error should we have a bad growing season.

I think we're running into a physical barrier. I think the biological processes we're looking at do not contain enough potential energy to satisfy demand. And even if we did find a biological system that did that, it'd likely wear out the soil pretty quickly.

We're barking up the wrong tree. The only real long term solution is to perfect electric cars (the research into improved batteries is being driven by hybrids right now, which I imagine is the only useful thing that will ever come out of that technology), increase our use of nuclear power, and upgrade the electrical grid to support it. Not easily done, but it does have the advantages of 1) solving the problem rather than delaying it and 2) being physically possible.

[Mr. Lucky]

Well, I’ve driven over 40,000 miles in my E-85 fueled truck. When you’ve done the same in an electric vehicle, ping me so we can compare notes.

[JamesP81]

Well, I’ve driven over 40,000 miles in my E-85 fueled truck. When you’ve done the same in an electric vehicle, ping me so we can compare notes.

The problem is that E-85 fueled vehicles cannot replace gasoline powered vehicles. We just can't produce enough ethanol. There's literally not enough arable land in the country to do it.

Converting completely to ethanol is something that's probably not going to happen. Burning ethanol blend fuel is nothing more than putting the problem off until later.

[Rick_Michael]

Algae-biomass....only geniune alternative....with time.