So Cellulose, Yet So Far

Study touts environmental benefits of switchgrass-derived biofuel

Posted at 4:11 PM on 08 Jan 2008

Fast-growing switchgrass makes for a super-duper biofuel, says new research published in the Proceedings of the National Academy of Sciences. The five-year study of 10 Midwest farms concluded that switchgrass-derived biofuel can produce more than five times the energy consumed in manufacturing it, and emits 94 percent less greenhouse-gas emissions than gasoline. "This clearly demonstrates that switchgrass is not only energy efficient, but can be used in a renewable biofuel economy to reduce reliance of fossil fuels, reduce greenhouse-gas emissions, and enhance rural economies," says lead researcher Ken Vogel. Well, great! Now we just have to wait for cellulosic ethanol to become commercially viable and cost-competitive, which should happen any ~~minute~~ ~~hour~~ ~~day~~ ~~week~~ ~~year~~ decade now.

sources: Omaha World-Herald, Environment News Service, Houston Chronicle, Nature

ADVERTISING POLICY

Comments: (5 comments)

You are not logged in. Thus, you cannot post a comment. If you have a Gristmill account, log in below. If you don't have a Gristmill account, well, by all means go make one! Meet you back here in five.

Switchgrass - what about biodiversity?

Clearly, switchgrass has some great potential once the technology to break down that pesky lignocellulosic material comes around. But, this is still a monocrop that does a great disservice to biodiversity considerations. I saw Vogel speak in December on "Environmental" impacts of switchgrass. When someone asked him about incorporating diversity (like Tillman investigates in the article below) he said, that we don't have time for that "fairytale" stuff. Doesn't sound like the best science to me - that's the way, USDA!

gCarbon]Negative Biofuels from Low]Input High]Diversity Grassland Biomass, by Tillman, D. et al., Science, 314. 1598]1600 (2006).

by Alan Turnquist at 1:14 PM on 09 Jan 2008

Concerned, but...

Alan wrote...

"...this is still a monocrop that does a great disservice to biodiversity considerations."

I too am concerned about the threat to biodiversity. This seemed like a good idea when presented as a means of preserving grassland bird habitat... the biomass could be harvested before or after nesting season. Great way to pay for prairie restoration.

But now they are talking about monocultures. I suppose if we are going to grow something for biofuel, switchgrass would be better than corn and it does serve as a transition to using other material. But someone really has to find a way to incorporate other plants into the system.

Alan also wrote...

"Clearly, switchgrass has some great potential once the technology to break down that pesky lignocellulosic material comes around."

The PNAS paper strongly suggests that Vogel based is conclusions on current hydrolysis/fermentation technology. So the projected yield of 5x the energy required to grow the stuff does not rely on waiting for better means of breaking down "that pesky lignocellulosic material". Indeed, the yield will likely be much higher in the near future.

The importance of the study, in my opinion, is not that this will be really cool once cellulosic ethanol becomes commercially viable and cost-competitive a "decade" from now, but that we are close to making it comercially viable and cost-competitive within a few years. And that we can expect even higher yields shortly after that.

This does not mean I approve, but I think we should recognize the full results of this study.

by wiscidea at 3:08 PM on 09 Jan 2008

Not in our lifetimes.

Nature has had several hundreds of millions of years to figure out a way to break grasses down into sugars. So far as I know all of them to date involve teeth physically destroying the bonds involved in order to expose them to symbiotic bacteria.

Follow an elephant or a bison around and you will get a wet smelly lesson in how well that works on average. Even termites discard much of their raw material leaving substantial energy yield in their droppings. Evolution is not so easily beat.

Meanwhile pyrolisis and Fischer-Tropsch reactions can handily turn all that cellulose into electricity, char, and methanol, all valueable. Assuming that drivers used PHEV's instead of internal combustion engines as primary drivers an overall increase in efficiency is possible.

The whole ethanol business is simply an attempt to save the oil majors energy monopoly. If you only have to purchase liquid fuel once a month or so and can plug into the grid at night getting free energy from your solar panels daytime output then they are a bit shut out of the picture.

One way or the other by the time my children reach my age most gasoline stations will be serving some other function than a dispensery for liquid fuels.

Put the Carbon Back

by Pangolin at 7:49 PM on 09 Jan 2008

Funny...in a bad way

Too bad the Democratically-controlled Congress has outlawed the use of forest slash and submerchantable material from our National Forests for use in some sort of biofuels. Instead, I guess we have to harvest and burn it, losing the pollution and energy to our atmosphere. Or worse, leave it all in place and let it burn catastrophically, incinerating ecosystems, endangered species and cultural resources.

All to solidify the strength of the current energy monopolies. All to show those dastardly timber companies that it is easier to log burned forests. All to satisfy those darned idealistic enviros that say wildfires are "natural and beneficial". All of them people who THINK they know what our forests need.

All at the expense of our forest ecosystems.

Scenic pics at http://Lhfotoware.blogspot.com

by Backcut at 9:01 PM on 09 Jan 2008

Such a hoot...

...when ideology trumps reason.

But what can a person do about it?

Thanks for the post, Backcut.

by wiscidea at 9:20 PM on 09 Jan 2008
[ Parent ]

The comments of Grist users reflect the opinions of those individuals only, and do not necessarily reflect the viewpoints of Grist, its staff, its board members, their psychotherapists, or their aestheticians. Got it?