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Synthetic Microbes for Biofuel Production: Fuels Rush In
Jon Lebkowsky, 22 Jul 06

petri.jpgOverhead is such a bummer. We could have so many more ready supplies of fuel if we didn't have to consider the energy cost of energy production. That's an issue with the U.S. corn-based version of ethanol production - the yield is low compared to the energy cost of raising the corn. Ethanol, considered a clean energy source because it spews adds almost no carbon dioxide into the atmosphere, can be produced from other sources, especially cellulose (wheat and rice straw, switchgrass, paper pulp, agricultural waste), more of which can be produced per acre.

The real factories for converting biomass to ethanol are organic - microbes that consume the sugars in biological feedstocks and produce sugar as a byproduct. The microbes come into play during ethanol fermentation, the last step in the conversion process, which currently has inefficiencies due to the heterogeneous and recalcitrant nature of cellulosic biomass and a mix of sugars that yields a broth of around 6% ethanol compared to the 10%-14% from cornstarch glucose fermentation.

Says an article in the current MIT Technology Review,

The more one can fiddle with the ethanol-producing microbes to reduce the number of steps in the conversion process, the lower costs will be, and the sooner cellulosic ethanol will become commercially competitive. In conventional production, for instance, ethanol has to be continually removed from fermentation reactors, because the yeasts cannot tolerate too much of it. MIT's Greg Stephanopoulos, a professor of chemical engineering, has developed a yeast that can tolerate 50 percent more ethanol. But, he says, such genetic engineering involves more than just splicing in a gene or two. "The question isn't whether we can make an organism that makes ethanol," says Stephanopoulos. "It's how we can engineer a whole network of reactions to convert different sugars into ethanol at high yields and productivities. Ethanol tolerance is a property of the system, not a single gene. If we want to increase the overall yield, we have to manipulate many genes at the same time."

Others, such as Craig Venter, want to build whole new organisms. Venter has founded a company, Synthetic Genomics, Inc., which "seeks to lead the world in its ability to design, synthesize and assemble specifically engineered cell level bio-factories." Venter is the guy who cracked the human genome and sailed the world in an attempt to collect DNA from all species. He also has a science foundation, which he formed to support three initiatives: The Institute for Genomic Research (TIGR), The Center for the Advancement of Genomics (TCAG) and the Institute for Biological Energy Alternatives (IBEA).

Synthetic biology for clean energy or any other purpose is certain to be controversial, however the SB community that's formed has created declaration that includes a recommendation to discuss "creative solutions and frameworks that directly address challenges arising from the ongoing advances in biological technology, in particular, challenges to biological security and biological justice" as well as "ongoing and future discussions with all stakeholders for the purpose of developing and analyzing inclusive governance options, including self-governance, that can be considered by policymakers and others such that the development and application of biological technology remains overwhelmingly constructive."

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Comments

Ummm.... Check your chemistry.

Burning ethanol *definitely* releases CO2 into the atmosphere. But the idea is that burning ethanol can be "carbon neutral" if you use biomass (something that grows and sucks carbon dioxide out of the atmosphere through photosynthesis).

As you point out, there are lots of ways of producing alcohol fuels (including ethanol). Corn is a pretty silly way to do it, since it costs so much energy to make it work in the first place, but it's still more-than-breakeven. Cellulose-based materials (wood chips, stalks, switchgrass) would be good. Microbial systems could (???) be far better.


Posted by: Bob on 22 Jul 06

See the MIT Technology Review article at http://www.technologyreview.com/read_article.aspx?id=17052&ch=biztech

"Burning a gallon of ethanol, on the other hand, adds little to the total carbon in the atmosphere, since the carbon dioxide given off in the process is roughly equal to the amount absorbed by the plants used to produce the next gallon."


Posted by: Jon Lebkowsky on 22 Jul 06

Yeah, that was my whole point. Burning ethanol *does* release carbon into the atmosphere -- any carbon based molecule burned in oxygen does. Period.

But the carbon is "offset" by the fact that the ethanol came from plants that (a while ago) took carbon out of the air through photosynthesis.

I just wanted to clarify.

Ethanol does release carbon dioxide into the atmosphere when it is burned, BUT that CO2 is *offset* by the plants (from which the ethanol is made, at least in this case) that fixed carbon through photosynthesis.

I have a Ph.D. in this, and have been studying it for years. So please trust me on this.


Posted by: Bob on 22 Jul 06

Hi Bob,
I wish I had a Phd in this field, and then I could probably evaluate the various biomass and algal schemes.

However, even with my non-technical background I an see that this is just a semantic game. Yes of course burning ethanol produces CO2, but the net effect is CO2 neutral because the CO2 originally came from the atmosphere. It is just being returned to where it originated, the net effect is zero, zip, zilch, nothing... which is a vastly different story to burning fossil fuels which accumulated over millions and millions of years. We are using 1000 barrels of oil each and every second! (84 million barrels a day.) That carbon based energy did not originate from our atmosphere in this geological era but accumulated over hundreds of millions of years. So please don't shrug off the CO2 neutral effects of ethanol in some kind of semantic trickery, global warming is too important an issue to muddy the argument in this manner.

Surely that Phd of yours could be better put to answering questions about the storage of ethanol — I understand it requires expensive rail freight cartage because it is too corrosive to shove down a standard fuel pipe? (That's also got to be a big energy loser just getting the fuel from where it is grown to where populations need it.)

Also, the ERoEI questions have not been sufficiently answered. It currently has too poor an Energy Return on Energy Invested to have any value. Lastly, the sheer volumes required seems to be another great challenge. Unless there really is some ENERGY POSITIVE method of growing vast amounts of algae in the desert, that old cliche remains.... there just is not enough arable land to scale up any biomass, biodiesel, or ethanol scheme up to meet demand.

Personally, I think we are better off designing more energy efficient cities like New Urbanism than we are wasting time wishing a biomass liquid fuel "silver bullet" will suddenly emerge to save the day. Peak oil is here. There are answers, but I undersand the experts are discussing massively electrifying most transport systems around public transport based on high ERoEI renewable energy systems like wind, solar chimney's, and maybe even some solar thermal and PV systems (although the ERoEI of the latter are not yet as high as wind.)

I'm interested in your comments Bob, where do you see biomass schemes playing a role?


Posted by: Eclipse Now on 22 Jul 06

To clarify further, I did't say that that burning ethanol adds *zero* carbon dioxide to the atmosphere, I said "almost no." I suppose it would have been more accurate if I'd said "adds" instead of "spews."


Posted by: Jon Lebkowsky on 23 Jul 06

Again, I was just trying to clarify the chemistry here.

The act of burning ethanol releases as much CO2 to the atmosphere as burning gasoline. (Both are basically the same kinds of hydrocarbons, burning in an oxygen atmosphere.)

The trick with the ethanol, depending on how you decide to make it, is that it orignates from plants that (sometime in the past) also removed CO2 from the atmosphere. (The same thing is technically true of fossil fuels, by the way, but they removed CO2 from the atmosphere hundreds of millions of years ago -- and so it's hardly relevant for the modern greenhouse warming problem.)

Anyway, I'm just trying to stress this point. Your ethanol car releases just as much CO2 into the air as your gas-powered car. The other difference is the ethanol was derived (in the recent past) from plants, probably, which means that the original plants probably sucked about as much CO2 out of the atmosphere -- althrough this is hardly a sure bet for some ethanol systems you could imagine...

I didn't mean to get anyone upset here, I just wanted to point out the basic chemistry behind this. It's important to keep these issues straight, I think.


Posted by: Bob on 23 Jul 06

Again, I was just trying to clarify the chemistry here.

The act of burning ethanol releases as much CO2 to the atmosphere as burning gasoline. (Both are basically the same kinds of hydrocarbons, burning in an oxygen atmosphere.)

The trick with the ethanol, depending on how you decide to make it, is that it orignates from plants that (sometime in the past) also removed CO2 from the atmosphere. (The same thing is technically true of fossil fuels, by the way, but they removed CO2 from the atmosphere hundreds of millions of years ago -- and so it's hardly relevant for the modern greenhouse warming problem.)

Anyway, I'm just trying to stress this point. Your ethanol car releases just as much CO2 into the air as your gas-powered car. The other difference is the ethanol was derived (in the recent past) from plants, probably, which means that the original plants probably sucked about as much CO2 out of the atmosphere -- althrough this is hardly a sure bet for some ethanol systems you could imagine...

I didn't mean to get anyone upset here, I just wanted to point out the basic chemistry behind this. It's important to keep these issues straight, I think.


Posted by: Bobo on 23 Jul 06

"The trick with the ethanol, depending on how you decide to make it, is that it originates from plants that (sometime in the past) also removed CO2 from the atmosphere."

Bob… what is the “trick”?… you are just stating the obvious…

"....although this is hardly a sure bet for some ethanol systems you could imagine..."

Please imagine me a bio-ethanol system that doesn’t get it’s carbon from the atmosphere…


Bob, you are doing a Ph D in this??? Forgive me, but I thought that higher-level thinking was needed for one of those things… certainly used to be back in my day.


Let’s straighten things out… there are three issues with Ethanol… the economic cost, the EROEI cost and the CO2 issue.

Dealing with these in reverse order:


(i) Ethanol itself may be CO2 neutral… but how did you make the ethanol??… how was corn/cellulose/sugar fertilized, irrigated, transported, DISTILLED and re-transported… using vast quantities of CO2-emitting fossil fuels?? Hardly CO2 neutral then…

(ii) EROEI… marginally positive or negative… depending on where grown and where the market is…

(iii) The economic cost… without subsidies ethanol (from corn) is MORE expensive than gas (& always will be due to the price of oil inputs).


Furthermore… after all this effort … you then want to be BURN the ethanol in a 30% efficient ICE?? Why not just burn the fossil fuels? And you get to leave the land for food!!

The biggest problems with Ethanol will always be:

(i) It is completely soluble in water at a max concentration of ~12-13%...so you have to heat the 7x the quantity of water too (with its very high thermal capacity)…to separate the ethanol by distillation.

(ii) Arable land availability/food production displacement needed… and that just to make even the smallest dent in oil usage…


And finally…long term… where is your INPUT for all of the above (fertilizer, transport, distillation) coming from once oil has gone???

Let’s forget Ethanol… it is a (financial) distraction being pursued by BIG-AGRI… not a viable, sustainable fuel source.


Posted by: GJ on 23 Jul 06

Hi Bob,
Thanks, I think that's more helpful. It is worth focussing on the vast amounts of accumulated time that fossil fuels represent. I'll just unpack what I think you were saying above.

Fossil fuels are actually millions of years {{{worth}}} of stored atmospheric CO2. So while ethanol and fossil fuels both originally obtain their CO2 from the atmosphere, with ethanol we are discussing a renewable and sustainable CO2 cycle that might occur within the same year. When we use ethanol, WE already removed that CO2 and are now putting it back.

The Co2 in fossil fuels packed away over millions of years. The dinosaurs and plankton and algae stored it for us. So for the purpose of illustration — not actual figures —

...a million years worth of stored CO2 released into the atmosphere over a lifetime is a vastly more dangerous CO2 cycle. :-(

It's time to put up a few solar chimneys. :-)


Posted by: Eclipse Now on 23 Jul 06

And I'd like to echo the concerns raised by GJ above. If we finally crack algae grown in seawater in the desert, and solar energy is used to pump all that water, then maybe we have a winner.

The moment we talk about corn, how did you grow the corn?
How did you harvest and process it?
How much energy did that use?
What is the final ERoEI?
(Is it worth doing, or is the ethanol just fossil fuels in disguise?)
What is the final CO2 count?
How much arable land gets used?
How do we eat, once our farmland is all used for growing 9% of our fuel instead of our food?

Until these very real questions are answered, I agree that it's a complete distraction. It really is time to buy a bike and start supporting local businesses and local farmers markets. Peak oil is going to change everything, and it may just be the wake up call we all need.


Posted by: Eclipse Now on 23 Jul 06

Jeeez... This isn't a very friendly bunch, is it?

I was just trying to point out that burning ethanol *does* release CO2 in the atmosphere (Jon's post kind of missed that point), and that it can be offset by the original photosynthesis that goes into the corn, switchgrass, whatever.

However, what others don't seem to realize, is that fermentation itself can also release CO2 -- during the process when ethanol is formed. And, has been quite well pointed out by Eclipse Now, there are all sorts of life-cycle questions.

Basically, the details really matter here...

Bob


Posted by: Bob on 23 Jul 06

I don't have a PhD, and I haven't been studying this for years, but I do know what I wrote, and I didn't write that burning ethanol doesn't release CO2 into the atmosphere. I'm not clear why you keep saying otherwise. You seem to be missing the word "almost" in the post. Reasonable people can disagree, but you're disagreeing with a misstatement of what I said. Hope it's not unfriendly of me to point this out. *8^)


Posted by: Jon Lebkowsky on 23 Jul 06

cellulosic ethanol for sure is much better than using food crops for fuels

greening the deserts could be a possible way to get out of the fuel/food competition scheme

and if highly capitalized countries for example like the usa or spain or israel do sample projects, it could also help to develop a peace-building way of direct investment into sustainable agriculture projects to direct the human energy away from agression/frustration into
sustainable community economy basic infrastructure build up


-greening the desert with permaculture like it is described in this project
situated in jordan
( http://www.permaculture.org.uk/mm.asp?nolinks=y&mmfile=news_greeningthedesert )


-cultivating salt tolerant plants ( halophytes ) for example salicornia

http://www.hindu.com/seta/2003/09/05/stories/2003090500300300.htm

"Salicornia has vast potential as forage, vegetable, oilseeds and raw material for a host of rural industries including the rural energy development, and employment generation.


http://www.leuchtendgruen.net/botanicolor/ebot13.htm
wool washers in biblical palestine burnt 'salsola-kali' (Salicornia) a plant rich in sodium, for their detergent.



Posted by: andreas buechel on 24 Jul 06

Here's the arithmetic that keeps giving me pause.

For a moment, don't focus on the kind of plant and how it's grown. Focus only on the efficiency of photosynthesis, which is under 5% in converting solar energy into biomass. (In comparison, on-the-market photovoltaic cells are routinely 15% efficient at converting sunlight to electricity. Efficiencies of 30% are in the lab right now.)

The United States uses over 3 terawatts (3 trillion watts) of primary energy. Worldwide, humans use over 13 TW. To produce 1 TW of power by converting sunlight into biomass would require all the photosynthesis of one seventh of the surface area of the United States.

That's grim arithmetic. So is every other kind of arithmetic concerning energy - but in my view, the least grim is the arithmetic of rapid and significant gains in energy efficiency. With our present wasteful practices, biofuels are about as significant as a fart in a sandstorm.


Posted by: David Foley on 24 Jul 06

The sun is the sole supplier of energy, other supplies may be cosmic energy. All this other 'stuff' is just middleman material that is useless in comparison to the ultimate energy providers.


Posted by: James Orman on 24 Jul 06

What would it take to convert ordinary, biowaste into energy? I heard about a project going on in Califoria that coverts dog poo in fule.


Posted by: PAUL on 31 Jul 06



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