June 15, 2005
Big Improvement In Biomass Energy Generation In Lab
Biodiesel takes another step closer to practicality.
Researchers from the University of Wisconsin at Madison have shown that it is possible to convert biomass materials like corn into fuel that could be used in diesel engines in a way that automatically separates the fuel from water. "This is a new process to produce liquid fuels from biomass," said James Dumesic, a professor of chemical and biological engineering at the University of Wisconsin.
The main advantage of this process is the reduction of energy needed to convert the biomass materials into a usable form.
The alkane fuel contains 90 percent of the energy of the glucose and hydrogen that the reaction begins with, said Dumesic. "Thus burning the alkane fuel would give you 90 percent of the energy compared to burning the glucose and the hydrogen."
The advantage of the researchers' process is that when alkanes are produced they spontaneously separate from water, said Dumesic. "In contrast to our process... ethanol must be separated from water by an energy-intensive distillation step," he said. "For our process, no energy is required to separate the alkane products from water."
This boosts the overall energy efficiency of the fuel. The ratio of energy derived from ethanol to the energy required to produce it is 1.1 to 1. The researchers' process has an estimated ratio of 2.2 to 1, according to Dumesic.
Note that the energy efficiency of current methods to create ethanol from corn is disputed. The 1.1 units of energy out per 1 unit of energy in to grow, harvest, and convert to ethanol for existing processes might be overly optimistic and so Dumesic's improvement might not yield 2.2 to 1 energy production efficiency. Tad Patzek at UC Berkeley and David Pimentel at Cornell University claim corn ethanol is not a net producer of energy while Mike Graboski at Colorado School of Mines claims it is. Who is right? I don't know. But I am unenthused by an energy source that will increase the demand for agricultural lands and water for farming to produce non-food products since plants are very inefficient at converting light to useful energy as compared to photovoltaic cells. Photovoltaic cells can produce the same amount of energy using much less land. See that last link for my arguments.
The process is not yet ready for practical use. But Dumesic thinks he can improve the process. Environmentalists ought to worry that Dumesic and other researchers will succeed in making biomass commercially viable. If that happens before wind, solar, and nuclear become more competitive suddenly much more land the world over will be shifted into agricultural usage at the expensive of the wilderness and of the creatures which live in the wilderness. Environmentalists ought to shift their focus away from opposing green house gas emissions and instead focus on efforts to develop better substitutes for fossil fuels. Environmentalists really ought to lobby much harder for photovoltaics research. I'd also ask them to lobby for fourth generation nuclear power plants but I suspect for most of them that is still a bridge too far.
My own preferences for fossil fuels substitutes are nuclear and solar. After those two I'd prefer wind over biomass. If it must be wind then I'd prefer offshore wind far enough from the coastline that it is not visible from land.
Update: To clarify one point: I am not opposed to all biomass energy technologies. For example, biomass technologies that can extract energy out of sewage or trash could reduce the cost of waste disposal, reduce the amount of pollution, reduce the growth rate of landfills, and provide energy. Development of such technologies strikes me as a big win. But what I'm at the very least unexcited about are technologies that will increase the demand for tillable land.
A fair degree of overlap exists between technologies that extract energy out of municipal waste and technologies that extract energy out crops. So advances in waste energy extraction are also advances in crop energy extraction. Though technologies that extract energy out of trash and other wastes likely will become cost effective well before those same technologies achieve profitability in agriculture. Why? Because in agriculture the fields have to be tilled, fertilized, planted, watered, harvested, and then transported to processing centers. Each of those steps cost money and cost energy too. Whereas trash and sewage already are collected and concentrated at trash dumps and sewage plants.
Also check out over on Green Car Congress Co-Production of Ethanol and Electricity from Waste about BRI's method of converting waste to ethanol and electricity and also the post New Revenue Stream for Corn-Ethanol Producers: Biodiesel. Plus, check out The Ergosphere for E-P's June biomass roundup. E-P does some calculations on conversion efficiency of the BRI ethanol/electricity conversion process and compares it to Changing World Technology's thermal depolymerization process.
I've had emails from people suggesting I post on CWT's technology. I was skeptical because I saw the collection of biomatter of sufficient quality as too expensive to make a large dent in total energy needs. Once the fairly small number of turkey, chicken, and like processing plants got the CWT technology installed other sources of raw biomass materials would be much more expensive. Well, it turns out that even in a Carthage Missouri ConAgra Butterball turkey plant the CWT technology is not ready for prime and produces energy that costs twice as much as it is sold for.
It turns out that process of cooking turkey guts, feathers, feces and other waste gives off a horrible stench.
“It's rotten,” said Beth Longstaff, a resident who was shopping at Wal-Mart recently. “You can't get away from it. It's like something out of a horror movie.”
The turkey oil is much more expensive to produce than projected — the cost of a barrel is double what it sells for.
Appel told The Kansas City Star recently that he doubts the process can be financially successful in the United States for several years. His company, Changing World Technology, has put on hold plans to build more plants in Colorado, Alabama and Nevada.
Instead, he is considering a deal to build a plant in Ireland, where costs would be considerably less, and where a recent news article predicted a plant should be operating by next year. Appel also is negotiating with officials in Italy and Germany.
But he has to solve the smell problem too.
While you were posting this, I was scribbling my own little analysis of the UWisc process and another; the results of my musings are at The Ergosphere.
Please do not compare apples to oranges. Biomass and solar are two very different technologies with different strengths and weaknesses. Biomass does not displace solar in any way, and it is unlikely that biomass will reduce food output at all. In fact, biomass will probably be a boon for farming, introducing growth in an industry that has been stagnant.
Biomass products can be stored and used to match demand. Solar is only available when the sun shines, and is not practical at higher latitudes except in summer.
The US still pays farmers not to farm tillable land, and produce is still dumped to support prices. Technology to improve farm production on marginal land is advancing impressively.
To the extent that processes like these can produce fuel and electricity from non-food matter like corn stalks and cobs, wheat and rice straw and tree bark and needles, they represent a distinct improvement over the status quo ante. If they can turn MSW into fuel and electricity (and eliminate the decay and settling process for the incombustible end product) they not only create fuel, they eliminate shipping and disposal costs (and the associated energy requirements) for waste.
Apples and oranges are both foods and you can compare their nutritional contents and health benefits.
Paying to not till land is done in part to preserve the topsoil. Thought it is mostly just a welfare hand-out to farmers.
With better energy storage technology (e.g. batteries or use electricity to run artificial photosynthesis systems to fix carbon and hydrogen) and dynamic electric pricing solar and wind could be used more widely (at least once their costs decline further).
Municipal Solid Waste.
(btw, your "Remember info?" option isn't working for me.)
notice it's all private financing (wonder how it compares $/W with your best estimate from cost of nuclear discussion?); it's next a major power transmission line to chicago; not in the flight path of migrating birds; the few hundred resident farmers are happy for the supplemental income.
" Zilkha Renewable Energy of Houston plans a $500 million wind development, to be completed in the summer of 2007. It will include 243 of the 40-story-tall structures. Chicago, by comparison, has 152 buildings at least that tall, with five more under construction, according to a Tribune survey.
It would harness enough wind energy to power an estimated 120,000 Chicago-area homes. With an output of 400 megawatts, it would outpower a 300 megawatt project in California that is now the nation's biggest."
The work that I've seen suggests that "typical" ethanol production (i.e. growing corn using standard practices) is roughly at the break even point. Now why would this be? Easy: subsidies. Whack the subsidies, and the inneficient producers will stop producing. It's certainly possible to to get net energy from corn, but frankly, it still isn't that great a deal.
The money in ethanol (if there is money at current fuel prices) would be in other crops, such as fast growing trees, where the cost of farming is much lower for the biomass produced. But there isn't the same lobby. Sigh...
Whack the subsidies, whack the oxygenate mandates, and re-instate the payments for acreage set-asides.
All money goes straight to the farmers, ADM is out of the loop, we save a pile on fertilizer and agrichemicals - MUCH cheaper.
FWIW, the reason the CTW/ConAgra plant is uneconomic to operate is because it is bidding against other consumers of the turkey offal instead of being paid to dispose of it. This was not expected at the time the plant was specified and sited, but the USDA isn't entirely predictable.
The stink is another matter, and it makes one wonder why this problem was not discovered in the lab, and why the exact nature of the odor (organic, H2S, SOx from burned sulfide) has not been named in the news. Something about that smells a bit fishy... or something.
I agree that biomass and solar are two different
discussions. Solar cells are not a realistic
solution until there is a massive expansion of
production capacity and an associated decline
in prices. A significant expansion is required in
infrastructure (factory construction), installation capacity,
storage (for supplies during the night) and distribution
capacity (if you expect the large surface area regions
to supply the areas of high density energy consumption)
for solar to be practical. That isn't going to happen
anytime soon unless political positions (and therefore
incentives shift quite significantly from where they are
now. On top of that production and disposal of the most
efficient photovoltaic cells available (GaAs) are
rather messy from an environmental standpoint.
The efficiency of solar conversion to biomass is low.
The best sugarcane efficiencies are around 3-4%. Other
other agricultural crops are lower. However it is possible
using photobioreactors to push these efficiencies to 6-8%.
Using genome engineering this could be pushed even higher.
The advantage of using engineered genomes is that using
solar ponds and engineered genomes, atmospheric CO2 could
be converted into methane which could be distributed using
exiting natural gas pipelines. This would be a sustainable
process unlike processes based on underground carbon and
Also worth noting is that as Tom Friedman points out in
the NY Times today  we already have the technology
to double average fuel economy (see ) and the use
of biomass derivatives (using current methods) or solar
ponds engineered to produce alcohol (future methods)
we could push fuel economy to 500 MPG (of gasoline).
Also worth noting is that one reasons that crops are
so inefficient from the perspective of water use is
that most (90%) of the water they consume (which doesn't
end up in the ground water) ends up being lost to the
atmosphere through transpiration . Only 10% of
the hydrogen in the water ends up being used to produce
carbohydrates (e.g. glucose) or hydrocarbons (fats).
One doesn't have that problem in solar ponds because
transpiration isn't required to get the water from
the roots to the leaves.
The problem you have in ponds is that any measure you take to reduce evaporation also obstructs gas exchange with the atmosphere and thus CO2 uptake.
This is one of the clever things about the hydrogen-from-algae scheme; since the product is H2, you don't have to worry about replacing carbon.