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Gasoline, diesel, and jet fuel directly synthesized by bioengineered e-coli metabolizing switchgrass without enzyme pre-treatment.


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In reply to an earlier post on Feb 13, 2012 1:47:22 PM PST
JGF: Meanwhile, we need electric cars and battery swap format standards. Why isn't this idea catching on?

BPL: Suivez l'argent.

In reply to an earlier post on Feb 13, 2012 9:03:23 AM PST
BPL: Duh.

Thanks for setting that straight. It's not as if I didn't explicitly explain that in item #3 in the OP.

In any case I'm glad the thread got bumped. I'm praying this approach works out. It promises to be a truly sustainable net carbon neutral to the needs of special applications where chemical fuels are required - like jets, cargo ships and long haul trucking. Meanwhile, we need electric cars and battery swap format standards. Why isn't this idea catching on?

http://betterplace.com

In reply to an earlier post on Feb 12, 2012 11:40:56 PM PST
A customer says:
And did that REALLY need spelling out yet again?

In reply to an earlier post on Feb 12, 2012 12:39:42 AM PST
DC: Biofuels are carbon fuel.

BPL: Duh. But growing plants take CO2 out of the air, as much as you get back when you burn them. So biomass fuels, unlike fossil fuels, don't raise the CO2 content of the air.

In reply to an earlier post on Feb 11, 2012 3:48:30 PM PST
D. Caswell says:
Biofuels are carbon fuel.

http://en.wikipedia.org/wiki/Biofuel

In reply to an earlier post on Feb 11, 2012 3:46:27 PM PST
Last edited by the author on Feb 11, 2012 3:47:08 PM PST
D. Caswell says:
> It's support of this line of research is why the right wing-nuts propose to eliminate the Department of Energy.

There's no shortage of fossil fuels. Are you seriously claiming that the government has done a good job with a national energy policy?

Posted on Jan 4, 2012 12:36:37 PM PST
Treehugger© says:
I haven't read through all the posts but an curious as to the politics of corn vs switchgrass

In reply to an earlier post on Jan 3, 2012 6:35:06 PM PST
Never ever is one thing. Never in the forseeable future is another thing.

In reply to an earlier post on Jan 3, 2012 5:28:25 PM PST
Re Feldman, 12-15 3:43 PM: "does this back of the napkin analysis change your opinions of the potential of biofuels to meet the special needs of transport in a post carbon fuel alternative energy future?" I don't really have a well-defined opinion on this; things are too iffy. The only thing that is really clear is that unsubstituted aliphatic hydrocarbons will always be essential for aircraft; there is no other energy storage - conversion system that will ever be able to do the job. (I am really sticking my neck out on this -- but I feel quite safe in doing so.)

Posted on Jan 3, 2012 9:19:26 AM PST
Last edited by the author on Jan 3, 2012 9:20:21 AM PST
Old Ben says:
It's support of this line of research is why the right wing-nuts propose to eliminate the
Department of Energy.

In reply to an earlier post on Dec 15, 2011 9:25:52 AM PST
EB: <<The possibility springs to mind of recreating something like the pre-modern prairie landscape, albeit with herds of grazing threshers.>>

That's the idea. Keasling was raised on a farm in the western great plains - where farmers face economic hardship because the hard red wheat they grow brings a small price. Switchgrass could mean economic renewal to these areas because the economics of fuel in a post oil future would give them an economically viable crop - on a wider range of lands. The modern buffalo of the new prarie would be the giant combines - harvesting the jet and diesel fuels of the post oil era. It's a dream, sure, but becoming more of conceivable reality all the time.

In reply to an earlier post on Dec 15, 2011 8:32:22 AM PST
A customer says:
I see from the article that it benefits from nitrogen fertilisers, but in moderate quantities. The possibility springs to mind of recreating something like the pre-modern prairie landscape, albeit with herds of grazing threshers.

In reply to an earlier post on Dec 15, 2011 8:22:24 AM PST
A customer says:
Yes, it is the technological advance which is really interesting. I can't help thinking, however, that the Holy Grail of renewable energy is a self-contained unit that one can leave out in a desert producing chemical fuel from light. For energy-density and portability, one still really needs a chemical fuel, preferably liquid. All renewable energy ultimately comes from the Sun. Deserts are largely available without detracting from productive land, wild or otherwise, and if you could get the requirements down to piped water the operation would be almost cost-free, environment-wise.

But of course all these advances are part of a technological trajectory, and represent new opportunities and alternatives.

In reply to an earlier post on Dec 15, 2011 8:08:53 AM PST
EB: <<The taking of yet more land into production worries me almost as much as taking existing production away from food, though. We have trebled the quantity of reactive nitrogen being introduced into the biosphere in less than a century as it is and marine environments are creaking under the strain of runoff.>>

Excellent points, EB. The topic of biofuels addresses one particular issue - the need for dense chemical energy fuel sources for certain types of transport. Cars can be powered by battery - and with battery swap technology the range issue goes away. However, battery technology doesn't scale to meet the needs of high energy uses like jets, freight trains and freighter ships and long haul big load trucking. There may well be engineering solutions to this applications in the future, but for now we need to address these needs when considering addressing carbon fuel emissions and the peak oil scenario. Biofuels can solve this problem by providing a portable chemical fuel supply that is endlessly renewable, and potentially carbon neutral.

The major existing issues with biofuels are: 1) existing ethanol biofuels are not drop-in replacements for existing fossil fuels. In practice they must be mixed with fossil fuels for existing engines. 2) ethanol produces formaldehyde and other undesirable pollutants. 3) Food crops are used - with all the contingent issues this provides,Keasling's bioengineering addresses all of these issues - plus it has a larger implication with far more sweeping scope:
1) Keasing's biofuels are complete drop-in replacements for existing fossil fuels. No mixing is required. 2) no formaldehyde is produced - only the usual pollutants we already know and deal with. 3) Keasling is working specifically to have his e-coli tailored for metabolizing switchgrass - not food sources. This is critical for several reasons: 1) Switchgrass is capable of being grown on marginal land not suitable for food crops. 2) Switchgrass resembles the original flora of the great plains of North America - and will have beneficial effects on such issues as erosion, runoff, pesticide use, and the fauna of the regions it is grown in. 3) Switchgrass has far superior biofuel yields to most food crops - in particular corn. It has 4 x the ethanol yield of corn for a a given acre. This is a huge game changer. The US has abundant marginal land - particularly in the southwest, western high altitude plains, and northern plains. It is possible that the amount of switchgrass cultivation I alluded to could be effected with a minimal impact on arable land. Remember that the US already devotes substantial acreage to corn cultivation for ethanol. This use could be eliminated.

Here's how the wiki characterizes the bioenergy potential of switchgrass:

"Switchgrass has been researched as a renewable bioenergy crop since the mid-1980s, because it is a native perennial warm season grass with the ability to produce moderate to high yields on marginal farmlands. It is now being considered for use in several bioenergy conversion processes, including cellulosic ethanol production, biogas, and direct combustion for thermal energy applications. The main agronomic advantages of switchgrass as a bioenergy crop are its stand longevity, drought and flooding tolerance, relatively low herbicide and fertilizer input requirements, ease of management, hardiness in poor soil and climate conditions, and widespread adaptability in temperate climates. In some warm humid southern zones, such as Alabama, it has the ability to produce up to 25 oven-dry tonnes per hectare (ODT/ha). A summary of switchgrass yields across 13 research trial sites in the United States found the top two cultivars in each trial to yield 9.4 to 22.9 t/ha, with an average yield of 14.6 ODT/ha.[14] However, these yields were recorded on small plot trials, and commercial field sites could be expected to be at least 20% lower than these results. In the United States, switchgrass yields appear to be highest in warm humid regions with long growing seasons such as the US Southeast and lowest in the dry short season areas of the Northern Great Plains.[14] The energy inputs required to grow switchgrass are favorable when compared with annual seed bearing crops such as corn, soybean, or canola, which can require relatively high energy inputs for field operations, crop drying, and fertilization. Whole plant herbaceous perennial C4 grass feedstocks are desirable biomass energy feedstocks, as they require fewer fossil energy inputs to grow and effectively capture solar energy because of their C4 photosynthetic system and perennial nature. One study cites it takes from 0.97 to 1.34 GJ to produce 1 tonne of switchgrass, compared with 1.99 to 2.66 GJ to produce 1 tonne of corn.[15] Another study found that switchgrass uses 0.8 GJ/ODT of fossil energy compared to grain corn's 2.9 GJ/ODT.[16] Given that switchgrass contains approximately 18.8 GJ/ODT of biomass, the energy output-to-input ratio for the crop can be up to 20:1.[17] This highly favorable ratio is attributable to its relatively high energy output per hectare and low energy inputs for production."
http://en.wikipedia.org/wiki/Panicum_virgatum#cite_note-plentiful_switchgrass-1

Read the whole article. There are substantial other benefits of cultivating switchgrass, from soil fixing to improved habitats for a range of birds and animals.

What was the other sweeping implication of Keasling's research? Well, his team has custom written genes in sequencers in order to introduce new traits in the ecoli they are using. This is the vanguard of a transformative technological approach with potentially vast consequences.

Posted on Dec 15, 2011 5:55:05 AM PST
A customer says:
I'm ambivalent about biofuels, especially after the food riots in 2008. That said, Joshua's points must be acknowledged and this is potentially a significant advance. The taking of yet more land into production worries me almost as much as taking existing production away from food, though. We have trebled the quantity of reactive nitrogen being introduced into the biosphere in less than a century as it is and marine environments are creaking under the strain of runoff.

Posted on Dec 15, 2011 3:43:44 AM PST
RAS, does this back of the napkin analysis change your opinions of the potential of biofuels to meet the special needs of transport in a post carbon fuel alternative energy future?

Posted on Dec 13, 2011 5:46:02 PM PST
Last edited by the author on Dec 13, 2011 6:49:03 PM PST
Finally getting back to this:
"The ethanol yield per acre for switchgrass is calculated at 1,150 gallons, higher even than for sugarcane" ..."If switchgrass turns out to be an economic source of ethanol, as some analysts think it may, it will be a major breakthrough, since it can be grown on land that is highly erodible or otherwise not suitable for annual crops. "
http://www.grist.org/#/article/biofuel-some-numbers

Now, we weren't talking about ethanol - we were talking about direct conversion by bioengineered critters into real fuels. Since both are metabolites of ecoli I'm assuming comparable yields for this analysis.

Arable acres in the USA: 400 million acres in active cultivation.
US oil consumption: 19 million barrels/ day.
Gasoline consumption: 9 million barrels/day - 378 million gallons/day. 138 billion gallons per year.
http://www.eia.gov/energyexplained/index.cfm?page=oil_home#tab2

400 million acres x 1000 gallons/acre= 400 billion gallons but we need only 35% of this - so 35% of the arable land - unacceptable.

So switchgrass could replace all the gasoline we get from oil at the cost of 1/3 our agriculture. Not a good solution - but remember my premise: biofuels for niche use - jet fuel, diesel for ships and long haul trucking - what about limiting it to that?

Jet Fuel: 522 million barrels/year (*40=20 billion gallons/year)
http://www.eia.gov/dnav/pet/pet_cons_psup_dc_nus_mbblpd_a.htm

Diesel is about twice as much again - so 60 billion gallons/year. That's the production of 60 million acres - about 15% of the US' land in agricultural production. That is a conceivable figure - especially when you consider they switchgrass can grow on land not usable for normal agricultural production.

In reply to an earlier post on Dec 1, 2011 10:12:52 AM PST
Re Yothgoboufnir, above: I agree. But we need to suppose that eventually Brazilians (and others worldwide) will want to have the same standard of living as exists in the US -- which means that the available energy per person should be comparable.

In reply to an earlier post on Dec 1, 2011 10:04:35 AM PST
I strongly suspect the difference in wealth -- i.e. consumption -- between the average US and Brazilian resident is a huge factor in why Brazil can claim self-sufficiency. Brazil is self-sufficient, but it should be noted that Brazilians are on average able to do rather less of all the things that consume hydrocarbons.

In reply to an earlier post on Dec 1, 2011 9:49:44 AM PST
Re Feldman, above: Good post. The idea is that population drives gross fuel demand, and arable area controls potential gross biofuel supply. If one person requires one acre of crop X for biofuel, then 200 million will require 200 million acres, more or less.

In reply to an earlier post on Dec 1, 2011 7:30:14 AM PST
RAS: << they [Brazil] have a huge land area in which the stuff can be grown, and smaller population per unit area than the US.>>

Brazil and the lower 48 contiguous states of the USA have virtually the exact same area. The USA is larger because of Alaska and Hawaii. Brazil's population is 200 million and the USA has 300 million (50%) higher - but I'm not convinced population size is a relevant factor here.

In reply to an earlier post on Nov 30, 2011 11:06:05 PM PST
Re Feldman, above: I saw the article. Indeed, the barrels/acre figure is critical; I have no numbers.

Brazil is producing a lot of ethanol from sugar cane. Which works for them; they have a huge land area in which the stuff can be grown, and smaller population per unit area than the US. And your prior post is right on -- although I think that the only absolutely essential user of aliphatic hydrocarbons is aircraft.

In reply to an earlier post on Nov 30, 2011 9:19:28 PM PST
Here's a 3 year old SciAm article saying that switchgrass was 5x more efficient than corn per acre in producing ethanol. Obviously that doesn't give us a barrels/acre figure for this ecoli procedure, but it's a good sign:

http://www.scientificamerican.com/article.cfm?id=grass-makes-better-ethanol-than-corn

In reply to an earlier post on Nov 30, 2011 9:11:50 PM PST
The point is that biofuels fill a niche need. You only use them in those applications where the density of chemical combustion energy sources are absolutely necessary such as aircraft, long haul trucking, transoceanic shipping, chainsaws... Etc. You don't use biofuels for grid power generation or even for cars or most portable motors.

As for yield, I will look for potential numbers. I'm aware it's a critical factor.

In reply to an earlier post on Nov 30, 2011 8:23:58 PM PST
Re original post: Interesting. But a major issue is yield; unless the yield can be made sufficient, growing switchgrass over the entire US would not produce enough biofuel to keep the country running. It will be interesting to see where this goes.
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Discussion in:  Science forum
Participants:  8
Total posts:  27
Initial post:  Nov 30, 2011
Latest post:  Feb 13, 2012

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