Enzyme cocktail converts cellulosic materials, water into hydrogen fuel

By Susan Trulove

BLACKSBURG, Va., February 16, 2009 -- Tomorrow's fuel-cell vehicles may be powered by enzymes that consume cellulose from woodchips or grass and exhale hydrogen.

Researchers at Virginia Tech, Oak Ridge National Laboratory (ORNL), and the University of Georgia have produced hydrogen gas pure enough to power a fuel cell by mixing 14 enzymes, one coenzyme, cellulosic materials from nonfood sources, and water heated to about 90 degrees (32 C).

The group announced three advances from their "one pot" process: 1) a novel combination of enzymes, 2) an increased hydrogen generation rate -- to as fast as natural hydrogen fermentation, and 3) a chemical energy output greater than the chemical energy stored in sugars – the highest hydrogen yield reported from cellulosic materials.

"In addition to converting the chemical energy from the sugar, the process also converts the low-temperature thermal energy into high-quality hydrogen energy – like Prometheus stealing fire," said Percival Zhang, assistant professor of biological systems engineering in the College of Agriculture and Life Sciences at Virginia Tech.

"It is exciting because using cellulose instead of starch expands the renewable resource for producing hydrogen to include biomass," said Jonathan Mielenz, leader of the Bioconversion Science and Technology Group at ORNL.

The researchers used cellulosic materials isolated from wood chips, but crop waste or switchgrass could also be used. "If a small fraction – 2 or 3 percent – of yearly biomass production were used for sugar-to-hydrogen fuel cells for transportation, we could reach transportation fuel independence," Zhang said. (He added that the 3 percent figure is for global transportation needs. The United States would actually need to convert about 10 percent of biomass – which would be 1.3 billion tons of usable biomass).

The most recent research is published in the Wiley journal ChemSusChem (Chemistry and Sustainability), in the article "Spontaneous High-Yield Production of Hydrogen from Cellulosic Materials and Water Catalyzed by Enzyme Cocktails," by Virginia Tech student Xinhao Ye and post doctoral associate Yiran Wang, both in biological systems engineering; Robert C. Hopkins and Michael W. W. Adams of the Department of Biochemistry and Molecular Biology at the University of Georgia; Barbara R. Evans and Mielenz of the ORNL Chemical Sciences and Biosciences Divisions, respectively; and Zhang.

The research is supported by the Air Force Office of Scientific Research; Zhang's DuPont Young Professor Award, and the U.S. Department of Energy.

• Learn more about Zhang's work.
• Read more about the ORNL work.

Read related news stories.

• “New processing steps promise more economical ethanol production”
• “Novel sugar-to-hydrogen technology promises transportation fuel independence”
• “Biofuel processes to be developed by French biotechnology company, Biomethodes”

IMAGE INFORMATION: Percival Zhang (left) discusses conversion of biomass to energy with Geoff Moxley, who recently received his master of science degree in biological systems engineering from Virginia Tech.

Contact Susan Trulove at strulove@vt.edu or (540) 231-5646.

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CES 2009: It's a Wrap! A Review of TreeHugger's Trip to CES

In wrapping up TreeHugger's trip to the Consumer Electronics Show, we wanted to review the ups and downs of the green presence at the trade show.

Read on for a recap of everything we saw at CES this year.

The Green Presence at CES Booths

Everyone Has an Eco-Corner
There were eco-corners galore, and most major gadget makers wanted to show to at least a small extent how they too are greening up. While quite a bit of it was green lip service, we're hoping that at least a few of the manufacturers we spoke with are earnest about the commitment to sustainability they had on display.

Hiding the Green Gadgets
Having a green side was definitely a theme here at CES, but it doesn't mean greener gadgets had any sort of priority. In fact, it was hard to even find them. It took a lot of searching and asking a lot of confused CES staffers before I finally found the new location of the Sustainable Planet zone, which was disappointingly small. The LG booth next door was bigger than this entire zone. And it was mostly full of solar devices, rather than really cutting edge green gadgets. It was certainly didn't live up to the hype in the literature.

There was green elsewhere in the tradeshow, though, you just had to hunt. In other sections we found booths for things like new HYmini chargers, iGO green technology, some neat ZigBee enabled devices for home energy management. It just took keeping your eyes sharp so that you could be sure to spot the green.

Spotting the Greenwash
And of course, sort out the greenwashing. There was plenty of that as well. Fuji's EnviroMAX batteries to Motorola's Renew phone were on the more blatant side, while other booths like Eco-Mount and Thermapak were slightly less guilty, though we can still say it's greenwashing. There is definitely a green bandwagon trolleying around and companies are hopping on right and left. The abundance of little green leaves on literature and "eco" this, "eco" that illustrates it. It'll take a lot to sort out what's real and not, but thankfully we have organizations like Greenpeace here helping us wade through it all.

How Green was CES?

Getting Around Las Vegas
And as for CES itself. Boy, they sure did want to say they're greener this year. With a tradeshow of this magnitude, it's understandable for some aspects of green to be left out for the sake of cheap convenience, but there was a lot of room for improvement. The shuttle system was incredibly efficient, but they could have hired on green transportation like bio-diesel or electric hybrid shuttles, rather than pollution spewing buses.

Recycling Versus Waste

While I did manage to find a few recycling bins lining one corridor, these were few and far between.

And lunches, while it utilized bioplastic as a supposedly greener option, were still ridiculously over packaged, and a whole lot of waste was generated because of them.

Coffee was offered...but it was Starbucks, with stacks of paper cups and plastic lids that were scattered every which way by day's end. You couldn't turn around without being faced with a pile of water bottles, and while they did have drinking stations, they were adorned with plastic cups, rather than paper or - even better - a note on where to find a reusable water container.

Only one booth - Nokia - was handing out reusable water bottles that I could find, but on the other hand, nearly every booth was giving out reusable bags. There was hardly a plastic bag to be seen, and the only paper ones spotted were from HP and they were on racks throughout the conference for attendees' convenience.

Up and Down the Tradeshow Floor
The escalators were well used, while the stairs were left neglected, which was a bit disappointing to see.

Even in the morning and mid-day when energy levels should be relatively high, nearly no one used the stairs - not even for heading to lower floors. It's understandable but disappointing that more people weren't taking the ever so slightly greener option of hoofing it. It would have been really cool if CES got the renewable energy bug that LG was demonstrating on a small scale, and powered at least a portion of the hall such as the escalators with solar.

Finding People Who Care About Green
And finally, while there were a whole heck of a lot of people here who couldn't care less about being environmentally friendly, cutting down on energy use, and recycling, there were plenty of people here who did indeed care - from Greenpeace to theElectronics TakeBack Coalition to booths like eco TakeBack and Recellular. At lease there was some exposure for conference goers to the notion that green is good.

There was even just a bit of wild green at the show.

It nearly got kicked out, but with enough hubbub from the owner, it got to stay.

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The Pros and Cons of Biofuels

The Pros and Cons of Biofuels

There have been studies that prove the many benefits of substituting fossil fuels (petroleum, etc) with biofuels such as biodiesel and ethanol. In its simplest sense, such biofuels are biodegradable which means they are derived from organic materials. They are naturally renewable. It can create numerous jobs since our own farmers can practically make them domestically. Consequently, our reliance on foreign sources of fossil fuels will be significantly reduced. Moreover, these biofuels emit nontoxic and cleaner emissions in comparison to traditional fuels. These alternative fuels also do not promote global warming, since the carbon they emit is taken back to the environment.

Biofuels are easily utilize but not readily accessible.

The use of biofuel is not complicated. Compared to other forms of renewable energy (solar, wind, etc), biofuel is far more simple and easy to use. It does not require special equipment or a modification in all engines. Any automobile will not need complex changes. The biodiesel can be readily combined with conventional petroleum diesel in your fuel tank at any point in time. In some instances, particularly true for ethanol, you may have to look for flexible fuel car models. If not, biodiesel can run most diesel operated engines.

Despite these benefits, it would take time for biofuels to be readily accessible due to lack of ethanol or biodiesel pumps at existing filling station.

Biofuels are renewable but crops are still not enough.

It is a fact that biofuels are derived from biomass that is renewable and biodegradable. For this reason, it will accordingly cause lasting effects on generations to come.

However, one major concern of wide scale biofuel production is the increased need of growing crops to meet the demand. This leads to some arguments, since it might require extensive land that may involve forests, wild habitats and agricultural lands.

Biofuels uses more energy than they can produce.

This had been an issue in so many years whether producing biofuels would actually need more energy than they can give.

Over the years, technology has significantly improved. A lot of researches and tests had been done to prove that biofuels like ethanol and biodiesel generate energy that is comparable to conventional diesel fuel. Ethanol puts out about 1.5 units of energy for every unit of energy used in processing it. In addition, biodiesel even has an output of 3.2 units of energy to every unit of energy used on its production. The "traditional" fuel like gasoline needs 20% energy based on what it can provide, or leaving you with only 80%.

Conclusion

To reduce the reliance on fossil fuel, conservation is still the primary strategy. There is no instant weaning on conventional petroleum diesel. It is quite impossible to totally replace it but instead the consumption must be decreased. Other sources of energy such as solar, wind, etc. are still needed. But this does not mean that biofuel have no future. As a matter of fact, it has a very promising potential. As an alternative to this "traditional" diesel or gasoline fuel, it is expected to yield significant energy security and environmental advantage to its consumers.

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Boeing to test biofuel on Air New Zealand flight

• Aviation company to test biofuel next month using oil from jatropha trees
• 
  
• Alok Jha, green technology correspondent
• guardian.co.uk, Thursday 13 November 2008 15.30 GMT
• Article history

Workers at a jatropha nursery in Dimbokro, Ivory Coast. Photographer: Kambou Sia/AFP/Getty

Boeing and Air New Zealand will fly a jumbo jet powered partly by biofuel next month, the two companies announced today.

An Air New Zealand jet will leave Auckland on December 3 with a 50-50 mix of jet fuel and oil from jatropha trees, in one of its four engines on a flight designed to show that jatropha biofuel is suitable for use in aviation as well as economical to produce .

"This flight strongly supports our efforts to be the world's most environmentally responsible airline," said Rob Fyfe, chief executive of Air New Zealand. "Introducing a new generation of sustainable fuels is the next logical step in our efforts to further save fuel and reduce aircraft emissions."

The jatropha nuts, which contain 40% oil, were harvested from trees in Mozambique, Malawi and Tanzania.

Friends of the Earth's biofuels campaigner, Kenneth Richter, welcomed the move to get the aviation industry to reduce the environmental footprint of its planes, but he raised concerns about the impact of biofuels. "Even jatropha is being linked to food price rises and habitat destruction. Current rates of growth in air travel mean it is not enough to switch to biofuels."

Robin Oakley, head of Greenpeace UK's climate change campaign, said: "We need a dose of realism here, because this test flight does not mean an end to the use of kerosene in jet engines. The amount of jatropha that would be needed to power the world's entire aviation sector cannot be produced in anything like a sustainable way, and even if large volumes could be grown, planes are an incredibly wasteful way of using it."

Boeing said their trees were grown on marginal land not required for food in India and south-east Africa.

Billy Glover, Boeing's managing director of environmental strategy, said that to prepare for the test flight, his team had tried to source biofuel reliably and economically for commercial aviation.

"The processing technology exists today, and based on results we've seen, it's highly encouraging that this fuel not only met but exceeded three key criteria for the next generation of jet fuel: higher than expected jet fuel yields, very low freeze point and good energy density. That tells us we're on the right path to certification and commercial availability."

Air travel contributes up to 5.5% of UK carbon dioxide emissions and the search for a greener alternative to kerosene jet fuel has been fraught with difficulty. Airlines cannot use standard biofuels such as ethanol because this would freeze at high altitude. Testing for the Air New Zealand flight showed that the jatropha-based biofuel was more suitable for flying since it froze at -47C and burned at 38C.

Chris Lewis, a fuels specialist at Rolls-Royce, which tested the jatropha biofuel, said: "The blended fuel meets the essential requirement of being a drop-in fuel, meaning its properties will be virtually indistinguishable from conventional fuel which is used in commercial aviation today."

Last month, Darrin Morgan, an environmental expert at Boeing, said biofuel-powered aircraft could be carrying millions of passengers around the world within three years, much sooner than most experts thought.

The Air New Zeland plane is not the first to use biofuels. In February, Virgin Atlantic successfuly tried a mixture of 80% jet fuel and 20% biofuel (made from coconut oil and babassu palm oil) in one engine of a Boeing 747 on a flight between London and Amsterdam.

Oakley said that technological advances in jet engines could only make a difference if there was a limit to the "massive expansion of the airline industry around the world."

"If Boeing were really serious about reducing their impact on the environment they would end their vocal support for a third runway at Heathrow and put some of their billions into high-speed rail technology instead," he said.

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BioFuels

Corn ethanol

Pluses: May reduce U.S. reliance on oil imports and enable moderate reduction in emissions of greenhouse gases compared with oil. Fosters the building of biofuels infrastructure.

Minuses: Ethanol is energy intensive to produce, and the recent boom has pushed corn prices to more than $5 a bushel (from $2 in 2006). That is increasing the cost of everything from beef to soft drinks. The biofuels craze is helping drive up grain prices worldwide as farmers devote more acres to corn and less to other crops. Over 450 pounds of corn are needed to fill a 25-gallon tank with ethanol_ enough calories to feed a person for a year.

Biodiesel

Pluses: Made from vegetable oils like soy and canola and animal fat, biodiesel provides 90% more energy than is required to produce it. Compared with petroleum-based diesel fuel, biodiesel is estimated to cut greenhouse-gas emissions 40% to 80%.

Minuses: Like corn ethanol, biodiesel's production from food crops boosts "agflation." European demand has been blamed for inducing farmers in Southeast Asia to burn and replant the rain forest with palm plantations, which has released large amounts of greenhouse gases. Production is limited at the moment_ just 250 million gallons in 2006.

Sugar-cane ethanol

Pluses: Sugar cane yields more ethanol per acre than corn, and it requires less energy to produce; hence, it is regarded as greener than corn ethanol. Sugar isn't a food staple, so making ethanol from it hasn't driven up food prices as has the production of large amounts of corn ethanol. Brazil makes nearly as much ethanol from sugar cane as the U.S. does from corn; cane provides nearly half of Brazil's transportation fuel from plants grown using about 1% of its arable land.

Minuses: Growing sugar cane requires a warm, rainy climate, which limits its potential as a global fuel source.

Cellulosic ethanol

Pluses: Made by breaking down wood chips, farm waste, and nonfood crops like grasses, cellulosic ethanol wouldn't require diverting the use of cropland. Scientists are making progress at breaking down plants' tough cellulose and lignin molecules, the key to turning nonfood biomass into fuel.

Minuses: Still costly and difficult to make, ethanol produced from nonfood plants is more energy intensive than that made from corn and sugar cane. By one estimate, putting all the grassland in the U.S. into fuel production could replace only about 10% of petroleum.

Algal biofuel

Pluses: The fastest-growing plants, algae theoretically can produce 30 times more energy per acre than other biofuel options. A particularly rich mix of byproducts can be made in algal-biofuels operations (everything from nutraceuticals to feedstocks for making plastics), potentially abetting their cost-effectiveness. This is the biofuels' dark horse.

Minuses: Unlike cellulosic ethanol, the biomass for making a lot of fuel from algae doesn't yet exist; it has to be grown from scratch. Harvesting is still expensive. Cost-effectively producing algal biofuels on a large scale may be many years away.

Source : http://money.cnn.com/galleries/2008/fortune/0804/gallery.green_biofuels.fortune/index.html

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How Green Are Biofuels? Comparison Chart

Biofuels are increasingly lumped into a single category of environmentally apocalyptic dead-end solutions. As the food vs. fuel debate rages on, it’s no wonder that the general public believes this.

But not all biofuels are created equal, as the chart above illustrates (click the image to see full size). It’s one of the best depictions I’ve seen of how each biofuel feedstock has completely different impacts on overall greenhouse gas emissions, water and pesticide use, and the energy required to produce the fuel. (Click on the chart for the full image)

Written by Clayton B. Cornell, Managing Editor

Source : http://gas2.org/2008/05/08/how-green-are-biofuels-comparison-chart-pic/

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Biofuels: 'Green gold' or problems untold?

Story Highlights
Biofuels have potential to make a positive impact on climate change
Boom in biofuel crops could increase competition between food and fuel
Opinion divided over claims that biofuels can meet growth in global energy needs
Strain on water supply and soil erosion possible down-sides to biofuel crops
By Rachel Oliver for CNN
(CNN) -- No subject appears to divide as many people in the climate change arena as biofuels. Their potential to positively impact greenhouse gas emissions is undoubtedly enormous.

But the pursuit of such non-fossil fuel energy replacements has raised concerns over the impact on the global food supply -- and the environment itself.

When people talk about biofuels they are essentially referring to ethanol or biodiesel, the former favored by the Americas (Brazil and the U.S. produce 90 percent of the world's ethanol between them); the latter preferred by Europe (accounting for 89 percent of global biodiesel production in 2005).

Biofuels can be produced from any number of plant crops; most ethanol in the world today being derived from corn, with sugar cane increasingly gaining favor (the latter providing double the yield per acre of the former).


Find this article at:
http://www.cnn.com/2008/TECH/02/24/eco.biofuels/index.html

Biodiesel emanates mainly from vegetable oils or animal fats, and waste cooking oil from China's restaurants has been to thank for supplying China's growing biodiesel industry.

Cellulosic ethanol, also fast becoming the darling of the biofuel movement, is produced by breaking down plant cell walls. And as cellulose is the most common organic compound around, it can be sourced from many more places and has the added bonus of turning things that used to be regarded as waste -- corn stalks, wood chips, grasses -- into incredibly useful sources of energy.

Are biofuels carbon neutral?

Biofuels are often referred to as being carbon neutral -- that is, the carbon dioxide (CO2) that is released through burning them is roughly equal to the amount they sequester when in plant form. In that way, growing biofuel crops helps ease global warming, their proponents argue, as they act as "carbon sinks" reducing CO2 levels.

In that way, relative to petroleum, biofuels could reduce greenhouse gas emissions by "more than 100 percent", World Watch says. Switchgrass and other grasses rate the highest in this regard, with the possibility of reducing emissions by between 70 and 110 percent (relative to petroleum fuels) compared to corn and wheat only offering maximum reductions of 40 percent.

According to the U.S. Departments of Energy and Agriculture, the 1.3 billion tons of "biomass feedstock... potentially available in the U.S. for the production of biofuels" is currently enough to replace around 30 percent of the country's existing gasoline consumption.

Most existing cars can use them immediately -- in small doses anyway (most gasoline-fueled cars can take up to a 10 percent ethanol blend in their fuel without any conversions). They are generally much better for your health when burnt too, reducing tailpipe carbon monoxide emissions by up to 30 percent, and fine particulate matter emissions by 50 percent, according to the Renewable Fuels Association.

Growing pains: Food vs. fuel

Biofuels currently only represent one percent of fuel used in transportation globally, but around one percent of the world's fields -- that's around 12 million hectares -- has already been turned over for their production.

But there are already questions over whether there is enough land available for biofuels to be able to replace even 50 percent of our fossil fuel use. According to The International Institute for Applied Systems Analysis, a maximum of 300 million hectares worldwide could be used for biofuels, but even if the biofuel industry used up 290 million hectares of that, it would only meet one tenth of the projected energy demands for 2030.

Europe only has a limited amount of land to set aside for biofuels, and according to the Soil Association, quoting OECD figures, if the EU gave up 72 per cent of its arable land, it would only only be able to serve 10 percent of its fuel needs.

Biofuels will however offer some economic incentives for developing nations. The concern is whether the pursuit of economic growth through biofuel production in developing countries will spur further deforestation and land conversions.

According to the World Food Programme (WFP) more poor African farmers are opting to sell crops like cassava for use as alternative energy instead of food -- purely for economic reasons. Some say, at least they are decreasing their reliance on increasingly expensive oil at the same time as 25 out of the 47 poorest countries on earth import all of their oil.

However others are warning of a vicious cycle being created by a dangerous food versus fuel competition, which will lead to food shortages, driving up food prices, and encouraging even more farmers to choose to grow fuel over food crops to meet the increasing demand (exacerbated by population growth) and clearing more land in the process.

It was on the subject of land clearing that the biofuel industry was chastised this month, in what could be the biggest blow dealt to biofuels yet.

A report from the Nature Conservancy and the University of Minnesota has raised serious questions over how biofuels are grown. Converting rainforests, peatlands, savannahs or grasslands to grow fuel crops releases CO2, in some cases a staggering 420 times more CO2 than from burning fossil fuel, the report says.

And that, they say, creates a "carbon debt" (with the emissions savings of biofuels fully considered) that could take as long as 840 years to cancel out depending on what land you are converting.

The worst land to convert is tropical peatland rainforest (creating a carbon debt of 840 years) or Amazonian rainforest (320 years) with the lowest carbon debt of 17 years created by converting the wetter woodland-savannahs of Brazil's Cerrado.

Creating new problems?

The methods used to grow fuel crops continue to be held under a magnifying glass; the initial furore over this new form of energy quickly dampened by realizations that in the pursuit of climate change solutions, nothing is ever simple.

Some have even questioned the role fertilizer is playing in climate change, with George Monbiot recently pointing out in The Guardian (based on a recent claim by the Nobel Laureate, Paul Crutzen) that using fertilizer on biofuel crops will be emitting enough nitrous oxide (more than 296 times more powerful heat trapping gas than CO2) to "wipe out all the carbon savings biofuels produce."

Biofuel crops could also put an unbearable strain on the global water supply, Sweden's Stockholm Environment Institute has warned. It says replacing 50 percent of the fossil fuels to meet 2050 transport and electricity demands with biofuels would require up to 12,000 extra cubic kilometers of water a year (the total annual flow down the world's rivers is 14,000 cubic kilometers).

China and India are at particular risk of water scarcity issues, the International Water Management Institute has warned.

The "best case scenario" many believe is making biofuels from native grasses and woody biomass grown on lands unsuitable for crop growing. The U.S. Agricultural Research Service recently found, for example, that growing native switchgrass on the prairies of Nebraska and North and South Dakota resulted in cellulosic ethanol yielding 5.4 times more energy than all the energy that went into producing it.

Native plants are also viewed as "carbon negative," as they are able to store excess C02 in their roots and the surrounding soil. But there are even downsides to using some agricultural and forestry waste products, as not only are they carbon sequesters but they provide nutrients for the soil. Removing them can lead to rapid soil erosion.

What Monbiot recently wrote in The Guardian reflects what many are increasingly coming to believe: "Apart from used chip fat, there is no such thing as a sustainable biofuel."

(Sources: New Scientist; Renewable Fuels Association, Treehugger, National Resources Defense Council; Department of Energy: Biofuel News; The Guardian; World Watch: Reuters )

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