Whatever Happened to Biodiesel?

Whatever Happened to Biodiesel?

Biodiesel made from vegetable oil seems to have good green credentials. Several musicians fill their tour buses with it, and environmental entrepreneurs brew it themselves from recycled kitchen grease.

However, expectations that this renewable fuel will deliver significant reductions in greenhouse gases may be too high.

"The general belief is that biodiesel offers a huge benefit from a global warming standpoint," said Russell Heinen, vice president of SRI Consulting, which last month released a biofuel report for the chemical industry. "We found that it's not necessarily that great."

Biodiesel and other biofuels such as ethanol release carbon dioxide when burned, but part of this is offset by the carbon dioxide absorbed by the biofuel crop. However, Eric Johnson, the report's author and editor of the journal Environmental Impact Assessment Review, found the environmental benefits of biofuels depend on what crops are planted and how the land might be used otherwise.

Surprisingly, European farmers currently growing rapeseed for biodiesel could reduce their carbon footprint by more than half if they planted trees and let regular diesel be burned instead. This is partly because commonly used fertilizers emit nitrous oxide, a greenhouse gas that has nearly 300 times more warming effect than carbon dioxide, which tends to get all the attention.

Fry fuel

Using vegetable oil or animal fats for fuel is hardly a new idea: The first diesel car more than a century ago ran on peanut oil.

Current diesel engines can be modified slightly to run on straight vegetable oil, but it's more common to chemically modify the oil to make biodiesel. Pure biodiesel can gel up in cold temperatures, so it is often blended with ordinary petroleum-based diesel.

Biodiesel is politically attractive as a way to lessen dependence on oil, while also supporting local farmers.

Government incentives and rising petroleum prices have helped the biodiesel industry grow by more than a factor of 20 in the past decade. The European Union has the largest biodiesel production worldwide with nearly 1.5 billion gallons last year, mostly from rapeseed oil. The United States comes in second in the groupings, with about 250 million gallons last year, mostly from soybean oil.

Plant forests instead

The United States, the European Union and other countries have mandated that biofuels make up certain fractions of their fuel consumption in the coming years, as part of programs to combat global warming and increase energy independence.

To determine the environmental impact of these policies, Johnson analyzed various biofuel scenarios. Generally, he found that emissions of nitrous oxide and CO2 from farming practices negated much of the carbon dioxide soaked up by the plants.

This was especially true for rapeseed, but environmental benefits could be reaped from other crops.

"Soy biodiesel and palm-oil biodiesel are generally better than petrodiesel on greenhouse gas emissions," Johnson told LiveScience. "It is mainly a function of crop yield and fertilizer amount."

Carbon footprint reductions of as much as 40 percent were possible from soy-derived biodiesel. However, in most cases that Johnson looked at, planting trees on the farmland and using regular diesel made a larger dent in carbon dioxide levels than producing and using biodiesel.

The results do not agree with other studies.

"The overwhelming evidence is that most biofuels offer a greenhouse gas savings," said Greg Archer, director of the Low Carbon Vehicle Partnership, a UK group that promotes eco-friendly cars and fuels.

The amount of savings depends on how the biofuel is produced. Smart practices—such as limiting fertilizer amount, heating with biomass instead of coal and generating electricity from waste heat—can make practically any biofuel less polluting than petroleum, Archer said.

Mcfueling

One way to be sure to reduce the carbon footprint is to reuse vegetable oil or animal fat to make biodiesel. Johnson estimated that waste-derived biodiesel releases 60 percent less greenhouse gas in its lifetime than normal diesel.

Recycling kitchen grease into biodiesel has become popular in small pockets around the country, where "the cars can smell like French fries when they drive down the street," Heinen said.

The U.S. Environmental Protection Agency estimates that restaurants generate some 3 billion gallons of waste cooking oil each year.

"The biggest problem is how dispersed it is at all the McDonald's and the like," Heinen said. "You need a concentrated supply to have an economy of scale."

One solution might be to locate a biodiesel factory next to a meat-packing plant or a potato chip manufacturer.

"Then at least you would have all the fat you need right next door," Heinen said.

 
Fats and oils from the home or restaurants can be turned into biodiesel. But much of this grease continues to go down the drain as experts argue over the environmental effectiveness of the idea.

Computer Model Predicts Outbreaks of Ethnic Violence

Computer Model Predicts Outbreaks of Ethnic Violence

Ethnic and sectarian violence that has plagued parts of Africa and Iraq in recent years can be predicted by using a model that examines the boundaries between different ethnic groups, a new study says.

While oppression of minorities, religious or political differences, and historical conflicts can be some of the triggers that motivate this type of violence, it is the structure of the boundaries that separate groups that enables communal violence, says study team member Yaneer Bar-Yam of the New England Complex Systems Institute.

If different ethic groups are very well-mixed in a community, violence is less likely to occur; if boundaries between groups are clearly defined, violence is unlikely to occur. But when the boundaries blur, and the amount of mixing is "just right," the situation can become explosive.

"That's the case that tends to promote violence," Bar-Yam said.

Islands and peninsulas

In the case of some well-mixed communities, it becomes harder for any one group to establish a collective identity or identify any one space in the community as belonging to them, and so no one group can dominate any others. Public housing in Singapore actually uses this principle to prevent sectarian violence by requiring a certain population mix, Bar-Yam said.

"There's tension there; there are historical events, but there's no major violence," he told LiveScience.

Conversely, groups that are separated by fairly rigid boundaries may have some antagonism between them, be it from religious differences or historical conflict, but the boundary prevents mixing, which minimizes the risk of violence breaking out.

In places like Ireland, "you have groups that sit side-by-side; there's plenty of historical events that might cause violence, and there's no violence," Bar-Yam said.

But where there is not significant mixing or boundaries to separate groups, people will tend to move to areas where there are people like them. This natural behavior can create "islands" of one population within another population or "peninsulas" that stick out from boundaries into other populations--the blurred boundaries between groups in these cases can create situations that allow violence to erupt. The group surrounding an island may impose their cultural norms on the group inside the island, which was the case in the former Yugoslavia.

"If people are in circumstances where their cultural behavior is being imposed or imposed upon, then they may very well find reasons to have conflict," Bar-Yam said.

Predicting violence

The model developed by Bar-Yam and his colleagues starts with the characteristics of the population (or the number of people in each grouping) and identifies the locations of population islands and peninsulas of particular sizes and marks the borders of these groups with other populations as a prime area for outbreaks of violence.

To check how well their model predicted the locations of outbreaks, the researchers took population data from the former Yugoslavia and India and checked the model's predictions against the locations of actual conflicts during the Bosnian War and in recent years in India.

The model's results correlated well with the places outbreaks actually occurred, with a 90 percent match between prediction and reality.

The model works independently of the particulars of the conflict, so it does not matter who is the aggressor, Bar-Yam says, also pointing out that the model makes no value judgments.

"The specifics of the group are not what's important," Bar-Yam said. "[The model] doesn't say, 'These people are right and these people are wrong'."

Bar-Yam says that the model could be used now in places such as Iraq to predict where outbreaks of violence will occur, and could be used by governments to formulate policies to prevent any outbreaks.

"Ethnic violence is really a horrendous thing, and to be able to provide information that can help prevent ethnic violence is really, obviously important," Bar-Yam said. "And having scientific tools that can contribute to the dialogue about what should be done is not only important but it is in some sense an imperative."

 
Prediction of regions of ethnic violence in the former Yugoslavia (red areas) by a model based on the population distribution of ethnic groups in 1991. The prediction map is shown in the context of a geospatial map of Europe. 

Fuel's gold: Termites point way to new dawn of bio-energy

Fuel's gold: Termites point way to new dawn of bio-energy

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.

Termites are typically a curse, inflicting billions of dollars in damage each year by munching through household timber with silent, relentless ease.

But gene researchers say the hind gut of a species of Central American termite "harbour a potential gold mine" of microbes which exude enzymes to smoothly break down woody fibres and provide the insect with its nutrition.

Present-generation biofuels are derived from corn, sugar and other crops, whose starch is converted into ethanol by enzymes, fermentation and distillation.

One of the problems, though, is that this product entails converting food into fuel. Hefty US subsidies to promote bio-ethanol is having price repercussions across swathes of the global food market.

Next-generation biofuels, though, 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.

Their work, published on Wednesday in Nature, required scientists to venture into the rainforests of Costa Rica, where they plucked bulbous-headed worker termites from a large nest at the foot of a tree.

Using fine forceps and needles, they extracted the contents of the third paunch, or hind gut, from 165 termites, and sent this to a lab in California for sequencing.

From this, some 71 million "letters" of genetic code emerged, pointing to two major bacterial lineages called fibrobacters, which degrade cellulose, and treponemes, which convert the result to fermentable sugars.

Termite guts are incredibly efficient, said Andreas Brune of the Max Planck Institute for Terrestrial Microbiology in Marburg, Germany.

"In theory, they could transform an A4-sized sheet of paper into two liters (1.8 pints) of hydrogen," he said.

Eddy Rubin, director of the Joint Genome Institute (JGI), an organisation that comes under the aegis of the US Department of Energy, said an important fundamental step had been made, even if a long road still lay ahead.

"Scaling up this process so that biomass factories can produce biofuels more efficiently and economically is another story," said Rubin.

"To get there, we must define the set of genes with key functional attributes for the breakdown of cellulose and this study represents an essential step along that path."

A coiled giant millipede rests on a log in the Budapest Zoo and Botanic Garden, July 2007. 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.

Sweden turns to a promising, but flawed, power source

A wind farm near Malmo, Sweden. The use of wind power in many European countries has stagnated in recent years. 

Sweden turns to a promising, but flawed, power source

Steadying himself on the heaving foredeck of an inspection ship recently, his face flecked by spray, Arne Floderus pronounced it a good day for his new offshore wind farm.

A 30-mile-an-hour wind was twirling the fingerlike blades of a turbine 380 feet above his head. Around him, a field of turbines rotated in a synchronized ballet that, when fully connected to an electrical grid, would generate enough power to light 60,000 nearby houses.

"We've created a new landmark," said Floderus, the project manager of the $280 million wind park, one of the world's largest, which was built by the Swedish power company Vattenfall.

The park, in a shallow sound between Sweden and Denmark, testifies to the remarkable rise of wind energy — no longer a quirky alternative favored by environmentalists in Denmark and Germany, but a mainstream power source used in 26 nations, including the United States.

Yet Sweden's gleaming wind park is entering service at a time when wind energy is coming under sharper scrutiny, not just from hostile neighbors, who complain that the towers are a blot on the landscape, but from energy experts who question its reliability as a source of power. 

For starters, the wind does not blow all the time. When it does, it does not necessarily do so during periods of high demand for electricity. That makes wind a shaky replacement for more dependable, if polluting, energy sources like oil, coal and natural gas. Moreover, to capture the best breezes, wind farms are often built far from where the demand for electricity is highest. The power they generate must then be carried over long distances on high-voltage lines, which in Germany and other countries are strained and prone to breakdowns.

In the United States, one of the areas most suited for wind turbines is the central part of the country, stretching from Texas through the northern Great Plains — far from the coastal population centers that need the most electricity.

In Denmark, which pioneered wind energy in Europe, construction of wind farms has stagnated in recent years. The Danes export much of their wind-generated electricity to Norway and Sweden because it comes in unpredictable surges that often outstrip demand.

In 2003, Ireland put a moratorium on connecting wind farms to its electricity grid because of the strains that power surges were putting on the network; it has since begun connecting them again.

In the United States, proposals to build large wind parks in the Atlantic off Long Island and off Cape Cod, Massachusetts, have run into stiff opposition from local residents on aesthetic grounds.

As wind energy has matured as an industry, its image has changed — from a clean, even elegant, alternative to fossil fuels to a renewable energy source with advantages and drawbacks, like any other.

"The environmental benefits of wind are not as great as its champions claim," said Euan Blauvelt, research director of ABS Energy Research, an independent market research firm in London. "You've still got to have backup sources of power, like coal-fired plants."

Blauvelt publishes an annual report on wind energy in which he discusses its flaws. People in the industry would accuse him of propagating myths, he said. Now, the criticism is more tempered.

"One of the big problems with wind is that people tend to get hyped up about it, very emotional," Blauvelt said. "The difference is that the arguments are becoming more rational."

None of this is to say that wind power has peaked. On the contrary, Blauvelt figures the industry is adding capacity at a five-year compound annual growth rate of 26.3 percent. That is faster than hydroelectric power in its early days and twice the recent growth rate of nuclear energy.

The United States, which is considered a pioneer in wind, added more generating capacity in 2006 than any year on record. With 11,575 megawatts, the United States is the world's third largest wind country, after Germany and Spain, and it is adding more capacity than any other.

Among new countries with significant wind capacity are Britain, Canada, Italy, Japan and the Netherlands.

"What we're seeing is a second wave of countries, which are starting to invest more heavily," said Christian Kjaer, the chief executive of the European Wind Energy Association in Brussels.

He said wind energy would benefit from two parallel trends: rising oil prices and a global push to tax carbon-dioxide emissions. "It's very good way of hedging against volatile oil prices and potentially volatile carbon costs," Kjaer said.

In Germany, where 20,000 wind turbines generate 5 percent of the electricity, advocates say wind will be critical to meeting the government's goal of generating at least 20 percent of all power from renewable methods by 2020. But the industry's growth is slowing for a variety of reasons.

Germany is running out of places to put the turbines because of restrictions on the location and height of the devices. And rising raw material prices are making wind farms more expensive to build.

"Under the current circumstances, Germany's climate protection targets are not achievable," said Hermann Albers, the president of the German Wind Energy Association.

Open land is not a problem in the United States, but wind parks have faced resistance, particularly in scenic locales near the shore. A private developer, Cape Wind, wants to erect 130 turbines in Nantucket Sound, off Cape Cod. It has drawn protests from some well-connected locals, including the Kennedy family.

Cape Wind said it hoped to obtain all the necessary permits by next year, which would enable it to be up and running by 2011. "It's been a long road," said Mark Rodgers, a spokesman for the developer.

For a socially conscious society like Sweden, wind turbines exert a fashionable appeal.

Today, they account for less than 1 percent of Sweden's electricity generation. But the government wants to increase annual wind power production to 10 terawatt hours, or 10 trillion watt hours, by 2015 from less than 1 terawatt hour now (the park off Malmo will produce a third of a terawatt hour).

Vattenfall hopes to develop an even larger off-shore park in the Baltic Sea, between Sweden and Germany. In all, the government has identified 49 sites that are suitable for wind parks.

Sweden has historically invested little in wind projects because it has two reliable sources of energy, nuclear and hydro, which each supply roughly half its power. And because hydro is renewable, Sweden already does well on the environmental balance sheet.

But these energy sources have their vulnerabilities: hydro, to low water levels; nuclear, to technical breakdowns. The Swedish government has also pledged not to build any new nuclear power plants.

"One of the key energy priorities for Sweden is to establish a third leg of energy production," said Anders Nyberg, political adviser in the Ministry of Enterprise, Energy and Communications.

Of course, Sweden does not need to build wind parks to get wind power. It could simply buy more surplus wind power from Denmark, which it uses, as does Norway, to pump underground water into elevated reservoirs. The water is later released during periods of peak electric demand to drive hydroelectric stations.

In this way, hydro acts as a form of storage for wind energy — addressing one of wind power's biggest shortcomings. Sweden's strength in hydro makes it a good candidate for greater development of wind power, according to analysts.

Sweden is subsidizing wind power through "green" certificates, which favor the use of renewable energy. The small extra cost is passed on to consumers.

While Swedes staunchly support wind energy, they are as susceptible to the not-in-my-backyard opposition as people elsewhere. For years, residents opposed the wind farm near Malmo, known as Lillgrund, particularly after the builders obtained permission to raise the height of the towers. But the campaign to block the project failed.

Still, Floderus said the process took far too long, and Vattenfall is urging the government to speed up the approvals next time.

As his inspection ship followed a zigzag course through a field of 48 turbines, Floderus pointed to Malmo's two other landmarks, visible in the distance: Oresund Bridge, a 10-mile engineering marvel that connects Malmo with Copenhagen, and the Turning Torso, an eye-popping 54-story skyscraper designed by the Spanish architect Santiago Calatrava.

Soon, Floderus said, the whirling blades of the Lillgrund wind turbines would take their place alongside those landmarks as symbols of the modern age.

Oddball white dwarfs embody new category of star

Oddball white dwarfs embody new category of star

Eight unusual examples of a burned-out celestial object known as a white dwarf detected in our Milky Way galaxy represent a previously unknown category of stars, astronomers said on Wednesday.

White dwarfs mark the end point in stellar evolution for all but the most massive of stars in the universe, with about 97 percent of stars, including our sun, destined to finish their existence this way, according to astronomers.

White dwarfs result from the collapse of star cores in dying stars whose nuclear fusion has ceased. They usually have a mass about that of the sun, but are only a bit larger than Earth because they have blown off their outer layers, leaving behind only a small, dim and extremely dense core.

University of Arizona astrophysicist Patrick Dufour said previously known white dwarfs have fallen into two categories: those with a hydrogen-rich atmosphere and those with a helium-rich atmosphere. But Dufour and three other scientists, writing in the journal Nature, described eight white dwarfs that break the mold by possessing carbon atmospheres.

The researchers think they may have formed from stars much more massive than the sun but not quite massive enough to explode as a supernova.

"It was totally unexpected because all of the white dwarfs we knew so far were either hydrogen-rich or helium-rich. So this is a completely new kind of star," Dufour said in a telephone interview.

These eight white dwarfs are located in our own galaxy between about 1,000 and 2,000 light years from Earth, Dufour said. A light year is about 6 trillion miles, the distance light travels in a year.

The scientists have spotted at least a couple of other white dwarfs that might fit into this new category, Dufour added. All of them were among about 10,000 new white dwarfs recently identified in an extensive survey effort.

After blowing off their outer layers, white dwarfs typically leave behind a core of carbon and oxygen that is cloaked by a surrounding atmosphere of hydrogen or helium. The eight newly described ones have atmospheres primarily of carbon, with little or no trace of hydrogen or helium.

"It will be a challenge to try to explain how they form and what does this tell us about stellar evolution," Dufour said.

They might have evolved from a star similar to a unique one called H1504+65, the researchers said. Astronomers think this star violently expelled all its hydrogen and nearly all its helium, leaving behind a stellar nucleus with a surface half carbon and half oxygen.

 
An artists' concept of the surface of the white dwarf star H1504+65, released to Reuters on November 21, 2007. Eight unusual examples of a burned-out celestial object known as a white dwarf detected in our Milky Way galaxy.