Termite Power
Posted by Robert Rapier on March 2, 2008 - 12:00pm
Topic: Alternative energy
Tags: cellulose, cellulosic ethanol, termites [list all tags]
When I was in graduate school at Texas A&M in the early 90's, I selected chemical engineering Professor Mark Holtzapple as my research advisor. His work was exactly in my area of interest: Biofuels from cellulose. Even then, I was very concerned about the unsustainable lifestyle we were living, and I was hoping to save the world. For a very good overview on what we were doing, see this PowerPoint presentation (note the Hubbert slide) or this article. In brief, what we were doing was searching for naturally occurring biological systems that convert cellulose to organic chemicals.
The primary system we studied was the bovine digestive system. Cattle are very efficient digesters of cellulose. They eat grass, and break it down via microorganisms that live in their digestive systems. So what we did was extract those microorganisms and attempt to convert cellulose in reactors that emulated the chemistry of the cow's stomach. And while we did have success, the conversion was never as efficient as it was inside the cow.
So, I spent time brainstorming other efficient cellulose digesters. It occurred to me that probably the most efficient digester of cellulose in the world is the termite. After all, even cattle can't break down wood. So I discussed it with Professor Holtzapple, and he thought it was a great idea. I searched the literature, and as far as I could determine, nobody had ever done it before. Therefore, I had no guidance at all with what I was attempting.
I arranged a meeting with a termite expert in Texas A&M's Entomology Department. He was very keen on the idea, so he supplied the termites. The next bit was tricky. The cellulose digesters that we were looking at were anaerobic microorganisms. Oxygen would kill them. Therefore we always had to take great care to get them into the reaction system without killing them. For the cows, it was easy. We filled up a bottle with nitrogen, stuck our arm inside a portal into the stomach of a fistulated steer (somewhere there is a picture of me with my arm in a cow's stomach up to my shoulder), extracted about a liter of stomach contents, and poured it into the nitrogen-filled bottle. We then transferred the contents to reactors that were being purged with nitrogen.
But with termites, it wasn't going to be quite so easy. The volume of material I would be extracting would be very small, and therefore it would be tough to extract it without exposing it to air (with the equipment I had to work with). The other problem I had was that there was virtually no information available on the chemistry of the termite gut. How was I going to know what kind of vitamins, salts, etc. to put in the reactor? What should the pH be? The final concern I had was that I didn't know exactly what the product of the reaction would be. I wanted a reaction system that would convert the cellulose to acetic acid or ethanol, and not all the way to carbon dioxide. But I really had no idea what I would get.
So, what I did was use the same reactor conditions I used for the bovine microorganisms, and I threw in a combination of live termites, termites with their hindguts opened up, and just some extracts from the hindgut. I figured that I had a pretty good chance, given this approach, to have some of those desirable microbes survive the transfer. I then let that combination ferment in the reactor for about a week.
When I tested the contents of the reactor, I was disappointed. I was after acetic acid to turn into ethanol, but what I got was butyric acid (which can be turned into butanol). But I wasn't interested in butanol, and the amounts I got were very small. Since I was nearly at the end of my research, and I didn't really have the facilities nor the time to figure out the termite hindgut chemistry (the real critical piece, in my mind), I abandoned my termite investigation. I still thought it was an excellent idea, and if someone had 3 or 4 years it would have made a great Ph.D. research project. But I had to move on and graduate.
Since that time, I have seen the idea come up on a few occasions. Because of my previous attempt, news of these attempts always catches my attention. I recently saw a new story on this:
Fuel's gold: Termites point way to new dawn of bio-energy
Here is an excerpt, describing this latest line of investigation:
PARIS (AFP) - A team of US scientists poring over the intestines of a tropical termite have a gut feeling that a breakthrough in the quest for cleaner, renewable petrol is in store.
Tucked in the termite's nether regions, they say, is a treasure trove of enzymes that could make next-generation biofuels, replacing fossil fuels that are dirty, pricey or laden with geopolitical risk.
Next-generation biofuels would use non-food cellulose materials, such as wood chips and straw. But these novel processes, hampered by costs and complications, are struggling to reach a commercial scale.
The termite's tummy, though, could make all the difference. Like cows, termites have a series of intestinal compartments that each nurture a distinct community of microbes.
Each compartment does a different job in the process to convert woody polymers into the kind of sugars that can then be fermented into biofuel. The US team has now sequenced and analyzed the genetic code of some of these microbes in a key step towards -- hopefully -- reproducing the termite's miniature bioreactor on an industrial scale.
"In theory, they could transform an A4-sized sheet of paper into two liters (1.8 pints) of hydrogen," he said.
To be sure, they are well beyond what I was attempting to do. They are sequencing genes, using an entirely different species of termite, and they are attempting to produce hydrogen. But the core concept is the same: Scale up the internal bioreactor of the termite to produce a desirable end-product.
I guess I was just ahead of my time. :-)
As a freshman medical student at Baylor in 1952 I was required to take Biochemistry. I recall being impressed when the professor explained why termites but not humans could digest wood. It had to do with a mirror image enzyme. Termites had this enzyme but humans had the reverse. I assume that he was correct??
Well, the kid on the block here sells 5 cents a glass lemonaide
This is way cheaper than what you can buy it for in the store,
maybe we could feed the world on lemonaide, from this kid?
It would be much cheaper!
Hi Robert,
You probably won't go for something that doesn't use a reactor, but mushrooms break down cellulose.
Chris
And carpenter ants make great use of that, with a symbiotic fungus instead of a symbiotic protozoan. We could too, betcha.
If the creepie-crawlies haven't stumbled upon a given biochemical solution over their gazillion-odd generations, it may be hard to do. We should look more closely.
I looked for this but couldn't find it. The do have a bacteria symbiot blochmannia floridanus. The thing I like about the mushrooms is that you can just do it and not worry about intellectual property. That is what I was teasing Robert about. And, you probably would not go broke. Lot's of work though.
Chris
Now I have it. Just had to recall back a bit. It is leaf cutter ant that cultivate fungus. http://www.zi.ku.dk/personal/drnash/atta/Pages/Leafcut.html
Since ants have a sweet tooth, perhaps these fungii produce more starch than protein and fiber.
This might work out better than mushrooms. But, it seems that the cycle is more complex that just producing
food:
http://www.asm.org/microbe/index.asp?bid=30329
Chris
Ah, good link Chris. Yes, I meant leaf-cutter ants but typed carpenter ants. One of the hazards of posting with too little sleep. I had been unaware of the complexity of the process involving specialized ant-poo enzymes though. There's no reason that evolution would select for simplicity per se, and moreover if it were simple to digest cellulose and produce net energy you'd expect a lot more organisms to have the ability as a fallback metabolic adjunct. Anything we find going on in ant and termite guts is likely to be complex or we'd see that it had evolved multiple times in different species. (Idle ponder - why is this only significantly seen in social insects - foraging efficiency and marginal EROEI?)
That seems like a good question. How far can we get with the idea that what in social insects is called cultivation, is called parasitism in the loners? Some wasps are evolved to lay eggs in caterpillers. If they were more social they might raise the caterpillers? Perhaps it is just a matter of needing to devote constant attention so the social structure is required?
Chris
Fungi does a great job of converting complex carbs into less complex carbs/protein.
One can find 'art' of furniture with oyster 'shrooms. Documentation of straw being used, then the colonized straw then being used for animal feed. (because few critters eat straw)
Now, if you are looking for a converting fungi for your backyard messing with - Koji (the fungus used for making sake)
Gem industries here in the US is where I get mine from. (post a reply if you want me to dig up the web page as they are mail order only.)
I really like this article, but not because I want to run my car on termite intestinal bacteria farts. :) I think humans should take a second look at termites because they are edible and could recycle suburbia into calories. Real detritovores eat detritovores!
There must be a secret ingredient in cow pats. A compost heap always goes better with a few added. However if the goal is to produce water miscible liquids via precise assemblages of bugs then I think problems are guaranteed. The first problem is optimising conditions for the microbes; these include temperature, nutrient levels, absence of competitors (that 'spoil' the brew) and acceptable levels of inhibiting wastes.
Secondly you have to extract the target fraction (eg ethanol) using energy intensive methods such as distillation. Contrast this to the making of whiskey, rum and brandy which still contain at least a few percent water and sell for way over $1.50/L or $5/gal. More money for less work in energy terms.
On the other hand with gasification at 650C the first round products are predictable. It's the next step to liquid fuels that is hard. Maybe the answer is to drive PHEVs charged by fusion power so we don't care too much about the incidental cost of liquid fuels.
I've often wondered why so little effort was being put into this. It obviously works; I'll bet total termite biomass would be one of the highest of any fauna. Indeed, I've experimented with swarming termites as a possible food source since you can draw large numbers of them with lights during tropical swarms. (so far the dog's love 'em; I don't have any recipes to recommend, but it will be a potential high-fat food source on my island if needed.)
But how about taking it the next step: humans who can digest switchgrass and sawdust? Hell, earth might actually be able to support a 10 billion population if people just grazed on shrubberies and stopped commuting to work. Perhaps we should bioengineer us some Eloi.
Thanks for posting this RR.
Back in 1982 I had my hopes heightened at the World's Fair in Knoxville. Now I see that what I saw there was just a lot of hype. Our government had no intention of following through with new energy innovations. I hope you can take a look at my peoplepowergranny.blogspot.com and vote in my poll on how much our government has let us down with empty promises.
One question pretty much in general about bacterial fermentation and I'll use acetic acid as and example. Originally almost all of the acetic acid (vinegar) was produced via bacterial fermentation but now this is only used for food vinegar. Acetic Acid for industrial use is produced via direct chemical synthesis and it on of the big petrochemical products.
I was unable to find its total production but its one of the basic chemicals we synthesis.
The point is if after all these years fermentation is not a competitive synthesis route for acetic acid except where mandated by law why would any fermentation process be expected to produce fuel at reasonable cost ?
We can't even do it today for industrial chemicals much less for fuel.
I just think we have a fundamental problem here. I'm not saying we can't do this in the future for fuels where we can't substitute but given the above I just don't see how it could ever be a replacement for today's fuel usage patterns.
In general most of the chemical we make also have alternative "natural" routes that have been used in the past. However its rare to see a natural product competitive in the bulk chemical market place and these are high value usages not fuel.
Acetic acid is made from methanol via the Monsanto or Cativa process. In turn, methanol is made via steam reformation from natural gas.
I'm not disagreeing with anything you said, but this economic advantage is underpinned by large quantities of clean, high EROEI feedstock.
This little discussion illustrates the problem with peak oil. Oil is really cheap in relation to non-oil feed stocks for almost any industrial process. When oil runs out, almost everything will be a lot more expensive. Some things will be more expensive than others and the overall differences will be small compared to what the price had been when oil was available. A big problem is to figure out now what will be cheapest then, in the future, using economic data from now, when the cost of everything is massively distorted by the availability of oil. We need to know what will be cheapest then because we will have very little time to do the development work when we start falling off the cliff.
DOE has changed over from sequencing mammals to sequencing the termite genome. Eddy Rubin (DOE) freely admitted that he didn't realize what the E in DOE stood for until recently. His words are far from encouraging:
I'm sure he has good intentions and perhaps he can grow enough poplars to make biofuels to run our plane fleet but there is no way that we can power all our cars and trucks with biofuels, unless you override the second law of thermodynamics. For a good overview on the subject check out UC Berkeley professor Tad Patzek's excellent powerpoint on the subject. He has published his views on biofuels in Science.
I'm sure we can develop good enzymes, but we still need to produce a very large amount of biomass (and transport it) to feed these future enzymes. Why burn it is a 30% efficient engine?
Electric vehicles for ground transport is the only realistic option in the medium and long term. Why throw good money after bad? Let the auto fleet die with declining oil supplies and start building new infrastructure. WE NEED OUR TOPSOIL FOR FOOD.
2) and we need our water for food production and 3) we need our bees to pollinate food and 4) we need our entire ecosystem to support human life.
Warren Buffett is investing in Burlington Northern and CSX because the trucking system is going to grind to a halt in 5-10 years.
possibly.
http://www.truckinginfo.com/news/news-detail.asp?news_id=59899
- Do not perform the lossy conversion of biomass to liquid fuels.
- Use the most efficient converters we have to turn the chemical energy into work.
If "The Billion-Ton Vision" is correct, we have more than enough biomass available to supply the actual energy we derive from petroleum motor fuels (after refining and engine losses); we just can't take the same lossy route to get there.Or, golly Gee, convert the photons directly into electrical power and by-pass all the photons to bio-mass to 'work' conversions.
If you have resolved the issues of storage and capital cost, by all means.
Production:
http://www.us.schott.com/photovoltaic/english/index.html
http://ovonic.com/me_images_solar_11.cfm
http://www.windside.com/
... Evergreen Solar ...
Storage:
http://www.ngk.co.jp/english/products/power/nas/index.html
... etc ...
Disclaimer:
I have no financial connection with any of these companies, though I did have some Ovonic stock in my IRA or 401K for a while. Or maybe I still do, I'd have to look. Being a shameful trader, I have advanced / retreated based on fad and fashion in my investments. My connection with these companies is largely sentimental, having searched for them after visiting The Oil Drum. (or simply followed links posted by others including E-P, thanks)
As for capital cost, that's another matter. With TPTB in the process of actively wrecking the economy it will be more difficult. If we had a "war on energy" maybe ... :)
I've talked up Evergreen Solar myself, but sodium-sulfur batteries are a solution for storage on the time scale of hours or days, not months. The major benefit of biomass is that it is fixed in chemical form and is relatively stable for some time; simple and inexpensive processing can increase that period of stability to more than the lifespan of the typical human civilization.
If you have a heap of PV and wind generation and some DCFC powerplants with silos of charcoal for the times when the first two are slack, it addresses most of the objections to an RE-based economy. I don't think sodium-sulfur can fill the same niche.
Sodium-sulfur batteries are essentially stable when cooled to ambient temperatures, and could last for eons. Of course it takes a few days with the resistive heaters to get them back online. But, yeah, they are essentially designed for peak leveling.
But most of the PV storage requirement is in the 18 hours or so when the array isn't producing an excess, isn't it? I'd think the hours/days time scale of NaS goes pretty well with PV. For cloudy / calm days, of course you need some additional storage...
If we could build something like a sodium-sulfur flow battery, seasonal storage of electricity might be practical. Size would be an asset; the larger it was, the less it would be affected by heat loss. But I've not heard of anything like that, so it may be a bit beyond today's state of the art.
There's the diurnal cycle, but there's also the annual waxing and waning of the availability of sunlight in much of the world (especially those parts which get cold in winter).
This is where technologies which store energy outside the converter win out; they can be made larger at much smaller expense than making bigger batteries. Flow batteries have tanks, fuel-cell powerplants have stores of fuel. If you harvest a supply of energy once a year, you have inherent storage of energy on a scale of months at no additional expense. This meshes well with intermittent sources like wind and solar.
I've resolved the issues the same way you've resolved all of your proposal issues.
On the capital side - how can *I* hope to change the tax laws?
Your point A was concern over the lossy nature - I just pointed out how loss can be adjusted.
Tax policy doesn't create capital, it just shifts it around. No amount of tax fiddling is going to make it worthwhile to charge batteries through the summer and heat with electricity in the winter.
I think you were rather badly off-target.
The loss in conversion of biomass to conventional liquid fuels is in the region of 50%, and the drivetrains which use those fuels range in efficiency from the 40's (medium-speed diesels) to 15% (typical gasoline-powered light vehicle); end-to-end efficiency is somewhere between 7 and 20-odd percent. If we pyrolized the biomass directly to gas and charcoal for use in high-temperature fuel cells, we could get something closer to 70%. Total useful output would be multiplied by a factor between 3 and 10. This is the difference between partial displacement of petroleum motor fuel, and near-total replacement of petroleum, natural gas and coal.
I think the catch is that everyone has their eyes on the same biomass:
Homeowners see wood as a fuel for heating and cooking. If other sources are scarce, they will cut down anything they can find.
Electrical utilities see wood as a renewable biofuel for their facilities. All they need to do is burn it or gasify it.
Wood is also an alternative for making furniture, benches and a lot of other things, if we don't have enough plastics and steel, because of energy shortages.
Somehow, the folks making liquid fuel for automobiles think that they will get the entire amount of excess biomass themselves. If they are going to grow their own, they will need to start very soon.
Oh yeah, you have to watch out for the fuzzy math. You can not use the biomass for everything. You might replace 30% of the oil used for gasoline OR you might replace 30% of the natural gas we use, but not both.
The forest products waste is after the lumber is sawed and the paper is made. It is another revenue stream for the forest products companies. The same with farm crop straw. The farmers can get some money from all that they can spare. Biomass can help, but it can not bring us the energy independence that people talk about.
Yes and no. Homeowners aren't looking to heat with corn stover or rice straw, to give one example.
But you put your finger on something that worries me: Suppliers lock into relationships and Congress likes mandates, so we probably have only one chance to get this right. We need to make sure that new biomass-based energy initiatives address as much of our combined energy, pollution and climate problem as they can.
Considering they burn cow dung in certain places of the world. I think it's safe to assume corn stover and rice straw will be candidates should no higher energy sources be left to burn.
All the better reason to use the straw in something which doesn't produce fly ash.
Edit: This comment was supposed to be a reply to the next comment, not this one. Sorry for the confusion.
An off topic comment about rice straw: It has very high silica content. When burnt, very fine silica particles are put into the atmosphere. It is an air quality nightmare. Think silicosis.
Really? Silicosis? I could swear that all the rice farmers burn their fields after the harvest. I'd see it every fall when I lived in Japan. Is it really that bad for you?
One of the more interesting recent discoveries regarding silicosis is that freshly-spalled silicate particles are at least an order of magnitude more dangerous than old weathered particles. Think broken chemical bonds, free radicals. Think of the difference between water and hydrogen peroxide.
So the dust from a quarry can be extremely hazardous, while environmental dust, though still somewhat unhealthy, is much less so. The phytoliths released from burning rice straw would fall in the second category in my estimation.
From an article by David Pimentel:
And yet here we have someone claiming that biomass could easily power all of our cars and trucks, with a few tweaks.
Fossil Fuels - Coal, Nat Gas, Oil, Propane, Wood, etc.
Nope, we Won't replace All of Those; but, we can make a pretty good dent in our gasoline/diesel usage.
A Billion Tons of Usable biomass could equal 100 Billion Gallons of Ethanol. Add in a 50% increase in energy efficiency (the new engines coming online are there now) and, goodbye gasoline.
Next.
Okay...
a barrel of oil is refined into 44 gallons of gasoline. We use 20m barrels of oil a day, or 880m gallons. In a year, that's about 320b gallons. Ethanol has about 60% the energy of gasoline, so 100b gallons (assuming yearly production) is equal to about 60b gallons of gasoline, or 19% of annual production. I think that half our oil goes to transport, so 100b gallons of ethanol could be 38% of our fuel. Not a trivial amount, but not a replacement either. It would go a long way however, assuming 1b tons of waste cellulose is available and has no competing uses.
That would probably be me.
What you fail to take into account is the gross inefficiency of the internal combustion engine. The actual work which gets to the wheels of vehicles in the USA amounts to perhaps 5-6 quads/year; biofuels are sufficient to supply this if efficiency can be improved far enough.
I would not characterize my proposal as "a few tweaks". It would require the wholesale replacement of the vehicle fleet, with most energy being supplied as electricity. Doing this completely would take around 20 years, and involve infrastructure upgrades as well. However, it would almost certainly be cheaper than the $20 trillion estimated for the cost of doing it with oil over the next 25 years, and cleaner too.