Biofuels on a Big Scale

Technocrat

Biofuels on a Big Scale

Ian Gibson

Mon Jan 07 21:06:53 -0800 2008

Environment.

manage

Now, the first large-scale study shows that switchgrass yields more than five times the energy needed to grow, harvest, and transport the grass and convert it to ethanol. The results could propel efforts to sow millions of hectares of marginal farmland with biofuel crops.

Biofuels on a Big Scale

By Robert F. Service
ScienceNOW Daily News
7 January 2008

On paper, making biofuels from switchgrass and other perennials that need not be replanted seems like a no-brainer. Use the sun's energy to grow the crop, and then convert it to liquid fuels to power our cars without the need for gasoline. But so far, experiments with these "cellulosic" crop-based fuels have only been conducted on small scales, leaving open the question of how feasible the strategy is. Now, the first large-scale study shows that switchgrass yields more than five times the energy needed to grow, harvest, and transport the grass and convert it to ethanol. The results could propel efforts to sow millions of hectares of marginal farmland with biofuel crops.
...more at the link http://sciencenow.sciencemag.org/cgi/content/full/2008/107/1?rss=1

Biofuels on a Big Scale

TykeClone

Mon Jan 07 21:33:23 -0800 2008
manage

It's not been a question of whether or not we can grow it. The question is whether or not we can transport the feedstock effectively, store it, and process it in a cost effective manner.

The article says nothing about how research is coming with making cellulosic ethanol cost effective to produce, but does discuss that farmers using modern techniques can grow large quantities of grass.

Biofuels on a Big Scale

phred14

Tue Jan 08 05:48:30 -0800 2008
manage

No the answer is in understanding who benefits from the current ethanol subsidies.

Until Monsanto and ADM manage to benefit from switchgrass (or prairie) ethanol, the big money will stick with corn.

No matter how little sense it makes, energy-wise.
No matter how much it drives up the cost of food.
No matter how bad the tortilla riots in Mexico.

Biofuels on a Big Scale

Thomas Lord

Tue Jan 08 11:39:08 -0800 2008
manage

Corn is big now as an emergency measure.

The energy companies are not in bed with GMO and big-Ag companies. Where do you think research into cellulosic conversion of crops like switchgrass is coming from?

-t

Biofuels on a Big Scale

Biofuelsimon

Tue Jan 08 02:47:23 -0800 2008
manage

The tall grass prairie center thinks that prairie produces more energy per acre than switchgrass. If only we could find a way to collect methane generated by Buffalo we'd have something that was sustainable and possibly green.

Biofuels on a Big Scale

Uncle Entity

Tue Jan 08 08:00:08 -0800 2008
manage

I couldn't find a yield for prairie grass but did find a bunch of people whining that they can't get subsidies and sell the grass for biofuel.

My old list:

Tons of Fiber per Acre:

Poplar (6 - 7 year growth cycle) 10 tons/acre

Pine (30 year growth cycle) 3 tons/acre

Kenaf 6 tons/acre

Hemp 12 tons/acre

Cotton 0.3 tons/acre

Flax 1.3 tons/acre

Switchgrass 8-12 tons/acre, link

Elephantgrass 12-16 tons/acre

Japanese Foxtail 16-18 tons/acre

Corn stower 2.7 tons/acre

Rice straw 2.9 tons/acre

Cotton stalks 2.1 tons/acre

Biofuels on a Big Scale

TykeClone

Tue Jan 08 08:52:55 -0800 2008
manage

Corn stower 2.7 tons/acre

I've been reading that the distillers grains (the leftovers from corn ethanol production) are a potential feedstock for cellulosic ethanol as well.

If you figure 180 bushels per acre corn production, you start with about 5 tons per acre of grain feedstock. This equates to 450 gallons of ethanol + 1.5 tons of distillers grains. If the distillers grains are further processed into cellulosic ethanol, yielding 135 gallons more ethanol with the current technology (and without having to deal with the transport and storage of bulk materials). PDF Article on DDG & cellulosic ethanol

Biofuels on a Big Scale

Charles E Hill

Tue Jan 08 08:56:36 -0800 2008
manage

More information from Mississippi's Strategic Biomass Initiative.

Biofuels on a Big Scale

Matt Fulkerson

Tue Jan 08 13:34:46 -0800 2008
manage

Has anyone used wood chips or pellets to fuel a boiler, such as this pellet boiler. I'm wondering if direct use of biomass would be a better use than conversion to ethanol. That said, I've heard that a rule of thumb in the northern part of the US is 20 acres of woods to provide enough renewable fuel for heat. Most people don't have there own 20 acre woods.
Entropy being the theme of the week, why not use the fuel to generate electricity in addition to just providing heat. Every watt expended generating and using electricity will heat the home just as well as the more direct route from high to low entropy. I think I'm repeating myself from a discussion several months ago. Oh well.

Biofuels on a Big Scale

Matt Fulkerson

Tue Jan 08 14:14:08 -0800 2008
manage

"high to low entropy" Oops, that should be low to high.

241,000 square miles

rubycodez

Tue Jan 08 13:45:43 -0800 2008
manage

I've seen claims of anywhere from 1000 to 1500 gallons of ethanol per acres of switchgrass. So let's assume we average 1200 gallons per acre per year. We use 142 billion gallons of gasoline per year, which is about the same as 185 billion gallons of ethanol. Divide by 1200, we get 154 million acres, or 241,000 square miles. 62.3 million hectares.

That's doable number, I was wondering if the total would be absurd. it's three nebraskas, but we do have that much crappy non-quite-arable land around

241,000 square miles

TykeClone

Tue Jan 08 15:44:24 -0800 2008
manage

From what I can tell, there are about 25 or 30 million acres of land already in the Conservation Reserve Program that would (if we are serious about energy independence) be available for this usage - much of it is already growing some form of biomass "crop". On top of that you can add scrub land or bottom land that is not currently farmed and get a bit more.

If cellulosic ethanol takes off, you'll also likely see a switch from corn to switchgrass in some areas if, for no other reason, than it should be less expensive to raise switchgrass than corn.

We'll also get a "bonus" of about 135 gallons of extra ethanol per acre of corn if the distillers grains are further processed into cellulosic ethanol (which if it works out would boost the production of ethanol from corn by 30%).

And I would think that if it is usable, even things like lawn clippings (we have 32 million acres of those in the US) and leaves could be collected and processed. The biggest issue with these kinds of feedstocks is foreign materials and dirt getting into the works.

My guess is that if we're serious about it there will be a place at the table for all of these feedstocks.

Biofuels on a Big Scale

turtledawn

Tue Jan 08 17:22:34 -0800 2008
manage

Perhaps if we do get into biofuels in a major, major way, we need to consider how to recapture the minerals contained in the feedstock. It would be a shame to have our 'renewable' resource wither and die off, just because we've oxidized all the soil minerals and they're now floating about in the atmosphere.

I suppose we could at some point attempt to extract them from the seawater, as that's where they'll end up eventually, and by then we may even know enough about our biomass crops' metabolisms to be able to mix a precise and perfect blend for each field.. Perhaps I am being pessimistic way too far into the future here.

Biofuels on a Big Scale

David Hemming

Fri Jan 11 03:20:50 -0800 2008
manage

You might be interested in this blog Biofuel – the burning issues, which discusses some of the points from a paper Challenges for deploying dedicated, large-scale, bioenergy systems in the USA by John Fike, David Parrish, Jeffrey Alwang and John Cundiff. The paper appears in CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 2, No. 064.