Oil Rig of the Future: A Solar Panel That Produces Oil

TOMADO DE: Scientific American, http://www.scientificamerican.com/article.cfm?id=biofuel-diatoms

BANGALORE, India—In the ongoing hunt for alternative fuel sources that are also cost-effective, researchers are looking into making biofuel from genetically engineered diatoms, a type of single-celled algae with shells made of glasslike silica.

These microscopic plants, commonly observed as a brown skin coating submerged stones in rivers and lakes and as phytoplankton in seas and oceans, typically contain oil droplets inside their cells. The oil is a food source for the plants in lean times. Scientific analysis of diatom oil has shown that it is very suitable for use as biofuel, says T. V. Ramachandra, a professor of ecological sciences at the Indian Institute of Science (IISc) here who is working on this project with IISc researchers Durga Mahapatra and Karthick Balasubramanian, along with Richard Gordon, a radiology professor at the University of Manitoba in Winnepeg.

Sitting in his book-lined office in a leafy corner of the IISc campus in Bangalore, Ramachandra proposes it might just be possible "to milk diatoms for oil just as we milk cows." He and his colleagues have been talking about a solar panel that could extract this oil instead of producing electricity.

The oil can be as much as a quarter of the total mass of a diatom cell, and if a way could be found to efficiently wrest it from diatoms, he adds, a hectare of "diatom cultivation could produce 10 to up to 200 times the oil that is produced by soybean cultivation," Ramachandra says. (This estimate has been borne out by other, independent research groups, as well.)

The researchers propose creating a biological solar panel, which will contain diatoms instead of photovoltaic cells. Diatoms would float about in a nutrient-rich water solution and produce oil when exposed to sunlight. Diatoms already secrete silica by exocytosis—a biological process by which cells direct secreted material outside the cell walls. If diatoms could be made to similarly secrete the oil they produce, then it could be easily harvested. (Because the oil is used as a reserve nutrient—like fat—diatoms have evolved no mechanism to secrete it.)

New diatom species
Diatoms may have other advantages when it comes to oil production. They multiply rapidly—some species double their biomass in as little as five hours. Diatoms are also quite numerous, with the estimated number of species exceeding one million. "There are 2,500 species of diatoms in India alone," says Balasubramanian, who is writing his doctoral thesis on these algae. He discovered three new species in India while hunting for those with the most oil content.

Ramachandra and his colleagues propose to genetically modify diatoms by manipulating the genes that produce oil so that they enhance its production. "It may be possible to genetically engineer diatoms so that they exocytose [release] their oil droplets," the researchers wrote in a paper outlining their thoughts, published in a recent issue of the American Chemical Society's journal Industrial & Engineering Chemistry Research: "This could lead to continuous harvesting with clean separation of the oil from the diatoms, provided by the diatoms themselves."

For instance, the water-based nutrient solution in the solar panel will cause the oil to separate out. Ramachandra envisages a process similar to cream rising to the top in milk.

As he and his collaborators put it, "with at least a boundary layer of water on the diatoms, secreted oil droplets would separate under gravity, rising to the top of a tilted panel forming an unstable emulsion, which should progressively separate. The oil could then be skimmed, very similar to the cream that rises to the top of mammalian milk that has not been homogenized."

Production cost
Many experts are intrigued by this study but point out that it is still too early to know how it will play out. Mark Hildebrand, a researcher at the Scripps Institution of Oceanography at the University of California, San Diego, says, "A major consideration" in development of such technology "is the economic costs of production."

To date, models have shown that "the only economically viable way to produce the large amount of biomass required to supplant a large portion of our fossil-fuel needs requires an open-pond system," Hildebrand says. Although he does not discount the value of systems such as proposed by Ramachandra, which could be especially useful for research, he says it's still too early to know.

"The basic concept is similar to proposing to grow agriculture crops in greenhouses instead of in open fields," he says. "On a large scale, it just costs too much."

Sustainable farming
But Ramachandra insists an advantage of the diatom solar panel is that it can be created and maintained with equipment and methods that are inexpensive. This is different from photovoltaic solar panels, which require sophisticated fabrication facilities, Ramachandra says. In tropical countries like India with an abundance of sunlight, biofuel-producing solar panels containing local diatoms could be placed in every village. Investigation has shown that diatom oil can be used as biofuel without further processing, says Ramachandra—another advantage. A further advantage is that diatoms consume carbon dioxide, so the diatom solar panels would be very sustainable.

So far, the team has cultured and studied different diatoms and explored approaches to genetically engineering them, but has yet to build a solar panel. Nevertheless, corporations such as Hindustan Unilever, Ltd., (the Indian subsidiary of the multinational Unilever) have shown interest by talking to the researchers a number of times.

The next step, Ramachandra says, is to figure out how to implement the diatom solar panel at the lowest possible cost.

Massachusetts pushes waste-based biofuels, holds off on corn, algae, and switchgrass

TOMADO DE: Scientific American, http://www.scientificamerican.com/blog/60-second-science/post.cfm?id=massachusetts-pushes-waste-based-bi-2009-08-20

In a decision that environmentalists are praising and biofuel producers are fuming about, Massachusetts has announced that waste-based biofuels are the only ones guaranteed to meet the state's renewable fuel standards.

The ruling could potentially leave algae-, switchgrass-, and corn-based producers high and dry, although it's not quite the ban that some news outlets have called it, says Massachusetts Department of Energy Resources spokesperson Lisa Capone.

In accordance with the state's Clean Energy Biofuels Act of 2008, petroleum suppliers are required to make 2 or 3 percent of their sales by volume from qualifying biofuels beginning July 2011. (The program officially begins July 2010, but the mandated volume will be waived in the first year.)

On Wednesday, the state said that waste-based biofuels qualified due to their likely 50 percent reduction in greenhouse gas emissions. For other fuels, however, the state would not be making a decision until the U.S. Environmental Protection Agency and California Air Resources Board agree on ways to analyze the greenhouse gas reductions from such fuels.

"The department is awaiting those results before we begin qualifying other types of biofuels," Capone says. "Biofuels from waste feedstocks will likely meet that threshold without the analysis."

That contentious analysis primarily relates to measuring the indirect greenhouse gas emissions caused by reducing domestic food production if agricultural fields are used instead to grow corn or switchgrass for biofuels. Experts say that other countries will take up the slack in the world's food supply, clearing forested land and therefore reducing the benefits of biofuels.

In July, Timothy Searchinger of Princeton University and 10 scientists and engineers, wrote in Science, that doing biofuels right means taking advantage of degraded lands, crop and forestry residues, and municipal and industrial wastes.

"There's a gigantic number of scientific publications that say this is the policy that should be followed," Searchinger says.

ExxonMobil Bets $600 Million on Algae

TOMADO DE: Scientific American, http://www.scientificamerican.com/article.cfm?id=biofuels-algae-exxon-venter

Oil giant Exxon Mobil Corp. is making a major jump into renewable energy with a $600 million investment in algae-based biofuels.

Exxon is joining a biotech company, Synthetic Genomics Inc., to research and develop next-generation biofuels produced from sunlight, water and waste carbon dioxide by photosynthetic pond scum.

"The world faces a significant challenge to supply the energy required for economic development and improved standards of living while managing greenhouse gas emissions and the risks of climate change," said Emil Jacobs, vice president of research and development at Exxon Mobil Research and Engineering Co. "It's going to take integrated solutions and the development of all commercially viable energy sources, improved energy efficiency and effective steps to curb emissions. It is also going to include the development of new technology."

Exxon Mobil's collaboration with Synthetic Genomics will last five to six years, Jacobs said, and will involve the creation of a new test facility in San Diego to study algae-growing methods and oil extraction techniques. After that, he said the company could invest billions of dollars more to scale up the technology and bring it to commercial production.

"We're not claiming to know all the answers," said Craig Venter, founder and CEO of Synthetic Genomics, which has so far done early work on algae strains. "There are different approaches to what is truly economically scalable, so we're testing things and giving a new reality to the timelines and expectations of what it takes to have a global impact on fuel supply."

Jacobs and Venter are mum about the specific technology the collaborative effort would employ. They said the team would investigate all options, including growing organisms in open ponds and in closed photobioreactors.

They added that they were likewise uncertain what end-product fuels would result from the collaboration. Other startup companies have announced that they were producing both synthetic crude and biodiesel using photosynthetic algae (Greenwire, April 28).

"As far as products to expect from this program, our intent is to make hydrocarbons that look a lot like today's transportation fuels," Jacobs said. "We want to produce hydrocarbons that look like today's refinery products, that can go into a refinery to be processed along with other petroleum streams and then used in the transportation fleet or even jet fuel. And we think we've got a good chance of doing that."

Exxon Mobil launched the partnership after years of being publicly opposed to investing in renewable energy. Privately, though, Jacobs said the company has been investigating the sector for years.

"It's fair to say that we looked at all the biofuels options," Jacobs said. "Algae ended up on top."

Others in the algae-biofuels industry say Exxon Mobil's investment validates the sector.

"A couple years ago, the petroleum institute said there's only a couple of years left for oil, and now they're really finally acting on that," said Riggs Eckelberry, president and CEO of OriginOil Inc. "Algae is the feedstock to overtake petroleum. It's the real alternative to petroleum."

Environmentalists were more cautious in their appraisal of the Exxon Mobil-Synthetic Genomics plan.

"They've never done anything like this before -- invested real money in the renewables sector," said Kert Davies, research director at Greenpeace. "We've always said [the oil industry] has to be part of the climate change solution. We can't solve anything without companies like Exxon helping."

He added, "I'm guarding my optimism."

Exxon Mobil's timing is noteworthy, Davies said, because of the ongoing energy and climate legislative fight.

"It's interesting timing as the oil companies are struggling to find a place at the table," Davies said.

Newly Uncovered Enzymes Turn Corn Plant Waste into Biofuel

TOMADO DE: Scientific American, http://www.scientificamerican.com/article.cfm?id=corn-biofuel-enzymes

Cellulose-loving fungi can cut biofuel costs by enabling existing corn ethanol plants to process cheaper, woody feedstocks such as corn stover

"Visualize three tons of moldy bread." It's not the most appealing image, perhaps, but it's a description of the moist mound of growth media tended by bioscientist Cliff Bradley and his partner, chemical engineer Bob Kearns at their biofuel facility in Butte, Mont., that could help cut ethanol costs at the fuel pump.

Selected soil fungi that eat cellulose—the hard-to-digest, structural component of woody plants—thrive on the big pile of putrefaction from which Bradley and Kearns harvest certain powerful enzymes. The special enzymes allow standard biofuel plants to produce ethanol at lower cost by replacing some of the high-priced corn (starch) they process with cheaper corn stover "waste"—the leaves, stalks, husks and cobs of the maize plant itself.

Replacing 35 percent of the corn (which goes for $4.28 a bushel) now used in a typical ethanol plant with inexpensive corn stover (at $65 per ton) could save a quarter on each a gallon of ethanol the facility produces, the researchers calculate. And that's before any blender's credit or tax benefits from government for processing cellulose. Bradley and Kearns say that the basic integrated starch–cellulose process also works for biofuels produced in Brazil where ethanol is distilled from sugarcane and bagasse, or highly cellulosic cane plant residue.

Supporting development of the promising new technology is Cupertino, Calif.–based AE Biofuels, which has constructed a commercial pilot facility in Butte, where the pair demonstrates their integrated fermentation technology to potential licensing customers. The patent pending process "can be a bridge to cellulosic ethanol," says Andy Foster, executive vice president at AE Biofuels. The use of cellulosic feedstocks effectively enables farmers and producers to squeeze more ethanol from each acre of farmland, he states.

AE Biofuels is one of several companies in the U.S. that is trying to jump-start progress toward greener biofuels made from nonfood feedstocks with high cellulose content. But most of the demonstration efforts have slowed or halted "since the banking meltdown which made it very tough to arrange capital," says biofuels expert George W. Huber, a chemical engineer at the University of Massachusetts Amherst. Despite last year's economic turmoil, however, new pilot cellulosic biofuel plants were opened by KL Energy, Verenium Corp., and POET, LLC, he notes.

For the past few decades, Bradley and Kearns—self-styled "industrial fermentation guys"—have focused on developing effective ways to raise hard-to-cultivate soil fungi that secrete the crucial enzymes. Unlike their competitors, they grow fungi on the moist surfaces of solid nutrient particles. Standard large-scale fermentation processes, in contrast, take place in water-filled tanks. "They put an organism in a tank where everything's in a water solution," Kearns explains, "and then they try to get enough oxygen in there to make the aerobic fungi happy." Rather than "trying to adapt the organism to a desired environment," the two researchers created an environment that suits the organism.

One of the pair's special enzymes readily degrades cellulose and another has the unique ability to break down corn starch at ambient temperatures, a talent that enables existing corn ethanol plants to incorporate cellulosic feedstocks into their standard starch fermentation processes. "The integrated process uses the same equipment, which is important now that capital financing is so hard to get," Bradley says.

Las algas: un biocombustible de gran potencial

TOMADO DE: Weblogs, http://weblogs.madrimasd.org/energiasalternativas/archive/2007/10/01/74977.aspx

Las algas se componen de organismos acuáticos que capturan luz solar y el dióxido de carbono para hacer la foto-síntesis y así producir su energía, y además producir aceites vegetales que se pueden transformar en biodiesel. El rendimiento en producción de biodiesel con algas es unas 300 veces superior al que se alcanza con soja y unas 25 veces al que se consigue con palma. A ello hay que añadir el tiempo record de crecimiento de las algas que es solo de unos pocos días lo que contrasta con los tiempos de crecimiento mucho más largos de las plantas oleoginosas.

Cuando se comparan las productividades (m³ de aceite producidos por km² de superficie) las algas alcanzan rendimientos (m³ aceite producido por km² cultivado) de 10.000-20.000 m³/km², que resultan mucho más elevado que el alcanzado por la colza (120 m³/km²), la soja (40 m³/km²), la mostaza (130 m³/km²) y la palma (600 m³/km²).

Al contrario que la soja u otros cultivos usados para la producción de biocombustibles, las algas no necesitan extensos terrenos de cultivo ya que pueden crecer en casi cualquier espacio cerrado, y lo hacen de forma muy rápida, de este modo que podrían desarrollarse en tanque en cualquier localización. Se trata de una fuente de producción de energía en continuo, inagotable y no contaminante porque no moviliza carbono fósil, sino que utiliza el exceso de carbono (CO₂).

Ciertamente, no existen otros captadores de radiación solar más eficaces que estos organismos fotosintéticos. Además crecen rápidamente y se desarrollan en unos pocos días, algo que no sucede con el girasol, soja, mostaza y palma. Su cultivo automatizado en grandes bio-reactores resulta sencillo. Otros factores tales como la influencia del pH del medio en el que se desarrollan o las diferencias en la temperatura diurna y nocturna se están analizando en detalle con el objetivo de aumentar aún más su productividad.

La tecnología de extracción del bio-combustible es relativamente simple. Incluye una primera etapa de prensado con la que se extrae aproximadamente el 70% del aceite y una segunda con un disolvente orgánico se alcanza hasta el 99%, si bien esta última encarece el proceso. Dada la viscosidad elevada que alcanza el aceite virgen original puede utilizarse directamente en los motores diesel una vez que se han adaptado para operar con este combustible altamente viscoso.

Los triglicéridos que constituyen los aceites vegetales pueden igualmente transformarse en mono-ésteres y glicerina mediante la reacción de trans-esterificación con metanol. Las moléculas que componen el biodiesel resultantes de este último proceso tienen un menor peso molecular y su viscosidad es sustancialmente más baja con lo que puede usarse como combustible en los motores de compresión. Evidentemente, el biodiesel obtenido por cualquiera de las dos vías no contiene azufre, no es tóxico y, además, resulta fácilmente biodegradable.