Tag Archives: energy

Mother Nature shows how to improve solar technology.

Yang, N, Y Zhang, J Halpert, J Zhai, D Wang and L Jiang. Granum-Like stacking structures with TiO2 –graphene nanosheets for improving photo-electric conversion. Small http://dx.doi.org/10.1002/smll.201200079.

Synopsis by Marty Mulvihill, Aug 01, 2012

Researchers have improved solar cell performance by looking to leaves. The prototype mimics a leaf’s chemical layers that catch the sunlight and send the energy to plant cells. The bio-inspired solar cells were 20 times better at creating electricity than traditionally designed solar cells made from the same materials.

Solar power is an attractive energy source because it is free, readily available, clean and sustainable. To tap into this rich resource, solar power cells installed on roofs and in deserts capture and convert light to energy. But current types of cells remain inefficient and costly.

Researchers have been trying for more than two decades to build better cells by mimicking plants’ ability to harness the power of sunlight. Plants – through photosynthesis – naturally do this.

The layered design is unique because it takes advantage of an often overlooked leaf architecture that improves the efficiency of energy conversion. The results of the Chinese study are published in the journal Small.

Leaves have a specialized, layered structure called a granum, which collects light from the sun and turns it into energy the plant can use. The researchers identified two key features of the granum that could help improve solar cells: a stacked structure and a design to efficiently transfer energy.

Inside a plant granum are thin alternating layers of pigment molecules that absorb the light and molecules that turn the sun’s rays into electrical energy then used in chemical reactions. The researchers modeled their solar cell on this design. They created alternating layers of titanium dioxide – which absorbs the light, and graphene – which transports the energy.

The addition of graphene to solar cell design allows more efficient transport of the energy away from the titanium dioxide. When the graphene layers were not used, much of the energy absorbed by the titanium dioxide was lost before it could be captured as electrical energy.

Since the graphene layers improve transport of electrical energy, the researchers used many more layers of titanium dioxide, collected more light and increased the amount of light collected.

The results show the alternating, layered structure found in a plant’s granum can improve the performance of solar cells. The design has not been tested in a full-scale solar cell device. More work needs to be done to improve the safety and efficiency of the synthesis process before solar cells based on this technology could reach the market.

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The above work by Environmental Health News is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.
Based on a work at www.environmentalhealthnews.org.

Silver speeds chemical reactions with oxygen.

Huang, Z,  X Gu, Q Cao, P Hu, J Hao, J Li and X Tang. 2012. Catalytically active single-atom sites fabricated from silver particles. Angewandte Chemie http://dx.doi.org/10.1002/anie.201109065.

Synopsis by Marty Mulvihill

In a new study, researchers report using silver in a safer, cheaper, cleaner method to run chemical reactions – specifically the widely-used and universally-important oxidation reactions. The new system works at low temperatures and is 10 times more efficient than previous attempts.

In the quest to save money and prevent waste when making chemicals for industrial and consumer applications, laboratory chemists are looking to a new generation of catalysts to speed up reactions with less mess. Catalysts are added to chemical reactions to help efficiently transform raw materials into products.

In a recent advance, researchers report how silver – placed in a specific pattern on a stable molecular nanostructure – can act as a catalyst and promote reactions at low temperatures using safe and abundant materials like oxygen in the reaction.

The new system is 10 times more efficient than previous attempts. It not only conserves resources, but it will help researchers better understand how to use oxygen in industrial applications.

The silver-based catalyst converts oxygen from the air into a chemically reactive form that allows common industrial chemicals to be made more efficiently. The products of these reactions are the starting materials for a majority of chemical products.

Unlike previous catalysts that promote chemical reactions with oxygen, this silver-based model performs very well at low temperatures. Temperature is a key consideration. Lower temperatures reduce the amount of energy and potentially the cost of running these important reactions.

The new catalyst created by researchers in China represents a 10-fold improvement over previous methods for making these chemical products.

Catalysts increase the speed of chemical reactions. Yet they are not affected in the process. This allows catalysts to be reused and has helped expand their use in a wide range of manufacturing applications.

In addition to working at low temperatures, the catalyst uses oxygen as the only additional reactant. Traditionally oxidation reactions have used harsh chemicals and generated large quantities of hazardous waste. In this reaction the oxygen is incorporated into the product without producing any additional waste.

The results will help chemists understand how to better activate oxygen. Oxygen is often slow to react with other molecules because the molecule is very stable. It is usually found as two atoms paired together, hence its chemical nickname O2. These pairs must be broken apart before the individual oxygen atoms can react with other chemicals.

The new catalyst breaks the oxygen atoms apart. It uses individual silver atoms located near a surface that does not have oxygen as part of its molecular structure.

Using advanced chemical analysis tools, the scientists precisely characterized and explained the reactivity of the silver atoms that are attached to the surface of manganese oxide particle support. They verified the structure of their active catalyst with advanced microscopy and X-ray scattering techniques.

The catalyst is only in the development stages. Before it is ready for use in the chemical industry, chemists will need to show that it can perform oxidation reactions cheaply on a wide range of organic molecules. Read more science at Environmental Health News.

Brewing bioethanol in a single pot.

Synopsis by Wim Thielemans, Nov 01, 2011

Nakashima, K, K Yamaguchi, N Taniguchi, S Arai, R Yamada, S Katahira, N Ishida, C Ogino and A Kondo. 2011. Direct bioethanol production from cellulose by the combination of cellulase-displaying yeast and ionic liquid pretreatment. Green Chemistry http://dx.doi.org/10.1039/c1gc15688h.

An innovative process promises to produce bioethanol from plants in one step instead of three, but finding an easy way to purify the needed plant cellulose hinders its usefulness.

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A more efficient way to produce biofuels from plants is possible by pretreating the woody material with a liquid salt before fermentation, report researchers in Japan who perfected the process in the lab. Yet, coming up with the usable, purified cellulose remains a big hurdle to the industry.

This experimental method is unique because it pairs an enzyme-yeast unit with ionic liquids to convert the plants into the liquid fuel known as bioethanol. The successful trial yielded 90 percent ethanol and 82 percent of the ionic liquid was recovered.

The one-step, one-container procedure is outlined in the journal Green Chemistry.

Cellulose is the most abundant renewable material available. Plants, algae and some bacteria produce in excess of 100 billion metric tons per year. The non-food material is an agricultural waste material. The ability to turn the unwanted cellulose into liquid fuel would be an important step toward reducing dependence on crude oil without using food crops.

It takes three steps to convert cellulose into the liquid fuel bioethanol. Step one treats cellulose and turns its rigid and ordered structure into more chemically accessible pieces. In step two, enzymes further break down cellulose into glucose, a sugar. Then, in step three, microorganisms such as yeast ferment the glucose to ethanol.

The new process takes a different approach. The cellulose is broken down with ionic liquids (step 1) then converted into ethanol (steps 2 and 3) with a yeast-enzyme pairing – all in a single pot.

This is a remarkable step forward because the enzyme, yeast and ionic liquid are together but don’t interfere with one another.

Ionic liquids are salts – a designation for chemicals made up of both a positively and a negatively charged component – that are liquid at low temperatures, unlike common salts such as kitchen salt. Bulky positive and negative groups that make up the ionic salts hinder their packing into a solid crystal. Thus, they stay liquid to much lower temperatures – even room temperature. Some ionic liquids have been shown to be good solvents for cellulose, which is otherwise very difficult to dissolve.

In this study, the authors attached cellulase – an enzyme that breaks down cellulose – to the outside of the yeast. By itself, this yeast-cellulase combination is not very effective at tearing apart the rigid and inaccessible cellulose structure. But, a winning recipe was found by combining a small amount of specific ionic liquids with the cellulase-yeast. The ionic liquid disrupts cellulose enough so that ethanol can be produced directly and efficiently from the pieces of cellulose.

This work shows some real promise, but as the authors point out, most cellulose is not pure. To turn biomass directly into bioethanol, this new one-pot process will need to either extract cellulose efficiently or convert the other natural materials that coexist with cellulose in the plants. Read more science at Environmental Health News.

 

Homing in on a cheaper Haber-Bosch process.

Read Original Article in Chemistry World (RSC)

Simon Hadlington
23 May 2011

A cheaper alternative to the Haber-Bosch process could have moved a step closer thanks to a new ruthenium-based catalyst complex developed by chemists in Germany.

Each year the Haber-Bosch process produces millions of tonnes of ammonia for the fertiliser industry by direct hydrogenation of nitrogen with hydrogen gas over a catalyst. However, this process needs temperatures of around 450°C and pressures of 300 bar, consuming vast amounts of energy.

Synthetic cycle

Synthetic cycle of the formation of ammonia from azide and hydrogen with x-ray crystal structure of the ruthenium(IV) nitrido intermediate in the centre
© Bjorn Askevold

Now, a team led by Sven Schneider at the University of Erlangen-Nürnberg and Max Holthausen at the University of Frankfurt have shown how a ruthenium complex with a nitrogen-metal triple-bond can split molecular hydrogen to produce high yields of ammonia at atmospheric pressure and temperatures of only around 50°C. The finding could point the way to solving the ‘second half’ of the Haber-Bosch process, the activation of hydrogen and hydrogenation of a nitrogen atom to create ammonia.

The German researchers synthesised a planar molecule with a ruthenium centre clamped by a nitrogen and two bulky flanking phosphine groups – known as a PNP pincer ligand. A nitrido ligand triply bonded to the ruthenium can then be introduced with an azide. This ligand combine with the hydrogen to form ammonia.

The mechanism of H-H bond cleavage that the team proposes has the first hydrogen atom moving to the nitrogen of the pincer with the other remaining on the ruthenium. This latter hydrogen is then transferred to the terminal nitrido ligand. This reaction repeats twice more to produce ammonia.

‘A key aspect of the system is the cooperative nature of the metal-pincer ligand fragment,’ says Schneider. ‘Both the transition metal centre and the ligand are crucial for the reaction to proceed. We have essentially modelled the second half of a Haber-Bosch type hydrogenation of nitrogen in solution.’ The next step is to try to find a way of splitting dinitrogen to obtain the single nitrogen attached to the ruthenium complex.

Commenting on the work, Christopher Cummins, an expert in nitrogen chemistry at the Massachusetts Institute of Technology in the US, says: ‘This work gives a clear demonstration of nitride ligand hydrogenolysis yielding ammonia. Now, if a nitride ligand with such reactivity could be obtained via N2 splitting then a homogeneous analogue of the Haber-Bosch ammonia synthesis would be at hand. The authors’ choice of robust pincer ancillary ligands to support the hydrogenolysis reactivity is probably crucial.’


Under the light, gold shines as it depollutes phenol from water.

Navalon, S, M de Miguel, R Martin, M Alvaro and H Garcia. 2011. Enhancement of the catalytic activity of supported gold nanoparticles for the fenton reaction by light. Journal of the American Chemical Society http://dx.doi.org/10.1021/ja108816p.

Synopsis by Audrey Moores
May 26, 2011

Just about everything – from cars to laptops to cells to chemical reactions – needs energy to start up and keep going. Now, chemists in Spain have stumbled on a way to use light – the simplest and most abundant energy source – to speed up reactions that may be used to degrade a water pollutant, phenol.

The results suggest light can drive a chemical reaction that uses minute quantities of gold, titanium and oxygenated water to degrade a chemical pollutant known as phenol. They report the results of their laboratory study in the Journal of the American Chemical Society.

Phenol is a contaminant in industrial effluents and municipal sewage that is commonly found in rivers and lakes. It can occur naturally, but the bulk of it in waterways is produced from making resins for plastics and the building industry, nylon fabric and medicines. Phenol is an essential building block to make bisphenol A, a plasticizer that is widely used in the resins that line food and drink cans. Phenols are also used in medicines and personal care products, such as ointments, mouthwash and throat lozenges.

People are exposed to phenols by eating or breathing them at work or through medicines. Phenols can irritate skin and extended exposure to high levels can lead to loss of appetite, nervous system problems and cardiovascular conditions.

In this study, researchers showed that light could help gold nanoparticles drive a new kind of chemical reaction. The breakthrough may be a very applicable solution to a common problem of cleaning up contaminated water in streams, rivers and lakes.

Making and destroying a molecule takes energy. So using the sun as a source is a good idea. After all, plants build and maintain themselves using sunlight as unique energy source

Already a large number of light-promoted chemical reactions are at play in consumer products. For instance, some windowpanes used in large buildings have a self-cleaning technology. Very small pieces of a material called titania cover the surface of the glass. Titania can harvest UV light from the sun and break the pollutants that adhere to their surface down into carbon dioxide and water. But using sunlight to make reactions go still has limitations. Water treatments remain a challenge.

In this study, Hermenegildo Garcia and his group deposited gold nanoparticles onto small pieces of diamond. They added a mixture of a pollutant – phenol – and hydrogen peroxide – best known as oxygenated water – onto the materials. Then, they exposed the mixture to light and they observed degradation of phenol.

Normally, hydrogen peroxide is powerful enough to break phenol down. But, in the presence of the gold and diamond material and light, they saw something quite amazing. The reaction was up to 10 times faster. They also found that the more light was shed on the mixture, the faster the reaction. This proves the central role of light in this new process. The reaction proceeded using either laser light or sunlight.

They discovered even more. Phenol degradation requires very acidic conditions, usually uncommon in streams and other waterways. In the lab, under dark and neutral pH – non-acidic – conditions, no reactions occurred. But, again, as soon as light was shed on the mixture, the particles degraded phenol and it disappeared. The products of degradation of phenol are not discussed in the report.

More studies are needed to show the process can work outside of laboratory conditions. Challenges include studying the gold containing materials’ resistance to natural conditions and figuring out how to expose the particles evenly to light in the cleaning unit. However this research shows promise in developing strategies to clean up polluted water.

See original post in Environmental Health News

Chemists convert seaweed to chemicals and fuels.

Kim, B, J Jeong, S Shin, D Lee, S Kim, H-J Yoon and JK Cho.  2011.  Facile single-step conversion of macroalgal polymeric carbohydrates into biofuelsChemSusChem 3:1273-1275.
Synopsis by Evan Beach
Apr 28, 2011

An innovative idea – if adapted to a large scale – could take advantage of an abundant but so far little-used raw material to make biofuels, according to a team of green chemists in Korea. The secret ingredient: seaweed.

Many varieties of seaweeds thrive in the world’s saltwater oceans and seas. Their growth is fueled by carbon dioxide. Unlike most conventional land-based plants, it is possible to produce multiple crops in a year without requiring fertile land and fresh water.

In recent years, microalgae – which are invisible to the naked eye – have been researched and exploited for use as fuels. Mostly ignored in this boom were the macroalgae – the kind you can see with your naked eye and find at the seashore. These seaweeds usually have lower oil content and have not attracted as much attention from chemists and manufacturers.

What they lack in oil, many types of seaweeds make up for in carbohydrates. The red algae species used in the current study is almost 80 percent carbohydrates. These sugars form long chemical chains called agar.

The Korean researchers found two ways to convert the agar into useful products.

In one, they found that agar reacts with an acid catalyst to produce a small molecule known as HMF. HMF is a valuable precursor to a variety of chemicals. To draw an analogy with petroleum refining, HMF would be considered the bio-based equivalent of a petrochemical like toluene that serves as the ultimate starting material for many commercial chemicals. The yield of HMF from the red algae was higher than expected, and this was attributed to unusual simple sugars and linkage patterns in the agar structure.

By adding a different catalyst to agar and introducing a solvent for the reaction, the yield was improved and two different chemical products were formed. Both of these chemicals are well known as biofuels and could be used as building block structures for specialty chemicals as well.

The product yields might be further improved by changing the seaweed growth conditions or even the species. Since the researchers discovered that the agar structure leads to unique reactivity, future work could take advantage of ways to tweak it towards a more favorable composition. Other combinations of catalyst and solvent could be explored as well.

Innovative Energy Technology Transforms Wasted Heat into Electricity.

US EPA Announces 2011 Energy Star Emerging Technology Awards.

Release date: 02/08/2011

Contact Information: Stacy Kika, kika.stacy@epa.gov, 202-564-0906, 202-564-4355

WASHINGTON – The U.S. Environmental Protection Agency (EPA) is recognizing two companies for innovative new products that recycle wasted energy and turn it into usable electricity in homes or small buildings. Micro combined heat and power (CHP) systems are an emerging technology that can help change how we use and produce energy in our homes while protecting people’s health. When offsetting purchases of coal-generated electricity in cold climates, this emerging technology can reduce energy use and curb carbon dioxide emissions by 20 to 30 percent.

As winners of the 2011 Energy Star Emerging Technology Award, Freewatt micro CHP system made by ECR International, N.Y., and the Ecopower micro CHP system made by Marathon Engine, Wis. are helping home and small building owners, particularly in the Northeast region, produce their own electricity, reducing their utility bills. These technologies capture wasted energy from space or water heaters and turn it into usable electricity from a single fuel source.

Although the technology has been successfully used in larger applications for many years, micro CHP systems have only recently been commercialized for small scale use in residential homes, apartment buildings and small office buildings. This year’s winning micro CHP systems met strict criteria for efficiency, noise, emissions and third party-verified performance. In addition to submitting laboratory test results, products were monitored in the field for a minimum of one year to be eligible for recognition.

More information: http://www.energystar.gov/emergingtech

Carbon-absorbent foam triumphs at 2010 Earth Awards

By Shanta Barley, guardian.co.uk

Thursday 16 September 2010

The Earth Awards: Revolutionary artificial foam
A revolutionary artificial foam which captures and converts the Sun’s energy more effectively than living organisms has won the Earth Awards 2010. Illustration: The Earth Awards

An artificial foam inspired by the meringue-like nest of a South American frog has won the 2010 Earth Awards. The foam, which could help to tackle climate change, soaks up carbon dioxide from the atmosphere and generates sugars that can be converted into biofuel.

The Earth Awards were set up in 2007 to bring together green start-ups strapped for cash with investors. Between March and May, over 500 designs were submitted to a panel of judges that included Richard Branson, Jane Goodall, David de Rothschild and Diane von Furstenberg.

The panel awarded $10,000 each to six finalists in August. Tonight, the winning design – a photosynthetic foam developed by David Wendell and Carlo Monetmagno of the University of Cincinnati – was awarded $50,000 at Marlborough House, London, as part of the Prince of Wales’ Start Festival.

The foam, which will be installed in the flues of coal-burning power plants, captures carbon dioxide and locks it away as sugar before it has a chance to enter the atmosphere and contribute to climate change. Due to its frothy structure, the foam can be up to five times more efficient than plants at converting carbon dioxide into sugar.

Wendell knows that the foam is manufacturing sugar – glucose – but he hasn’t yet managed to extract the sugar in order to convert it into biofuel. Wendell says creating a biofuel like this is desirable as it reduces the pressure to grow biofuel crops on land for crops, and keeps the price of staple foods like cereal and rice down.

The secret to the foam’s success is a protein that the Tungara frog uses as scaffolding in its foamy nests. “I read about a protein that the frog uses that allows bubbles to form in the nest, but doesn’t destroy the lipid membranes of the eggs that the females lay in the foam, and realised that it was perfect for our own foam. The foam contains a mixture of over 11 different enzymes harvested from bacteria, plants and fungi. It fixes carbon dioxide as sugars like fructose and glucose at a rate that exceeds that found in plants,” Wendell said.

According to Rick Fedrizzi, chief executive of the United States Green Building Council, one of the award judges, Wendell’s idea and those of the other finalists were “amazing but wouldn’t necessarily have seen the light of day without the Earth Awards”.

“Cash prizes are great but the real benefit of the Earth Awards is that your idea or technology is recognised by your peers,” says Fedrizzi. “Plus you get to network with venture capitalists, who might choose to invest in you at a later stage when your idea is more tangible.”

Fedrizzi’s favourite entry was the Sustainable Shell, a biodegradable home that can be built from the soil on which it sits. “You might be living in the Serengeti in Africa with access to nothing but mud and water, but by using these design principles anyone can build a strong, sustainable shelter,” he says.

Designed by Michael Ramage of the Department of Architecture at Cambridge University, the home will probably be a hit among NGOs seeking to rebuild regions like Haiti that have been devastated by natural disasters. It’s also very beautiful, says Fedrizzi: “It brings to mind centuries-old Moorish temples.”

Among the other finalists is Jamie Lim, a Malaysian ethical designer who has created a range of sunglasses hand-crafted from bamboo – a fast-growing, biodegradable and low-carbon alternative to plastic. For every pair of “KAYU” sunglasses bought, Lim donates $20 towards surgery that restores sight in the developing world.

Another design recognised by the awards was Arthur Huang’s Polli Bricks – a low-carbon form of cladding made from recycled plastic bottles that can be wrapped around buildings to insulate them. They come studded with solar-power LED lights and cost around ten times less than conventional cladding.

Not all of the entries into the Earth Awards were tangible structures, however. The Biomimicry Institute in Missoula, Montana, submitted Ask Nature – an open source digital library that allows people to find out how nature has solved problems that now confront humanity.

See original article here.

Fuel cell gets energy from water.

Aug 09, 2010

Dreizler, AM, and E Roduner.  2010.  A fuel cell that runs on water and air. Energy and Environmental Science 3:761-764.


Synopsis by Evan Beach and Wendy Hessler
2010-0723hyrogenfuelcell
Flickr/eston

Chemists in Germany have figured out a way to extract energy from just water and oxygen. The discovery uses existing fuel cell technology and minimal additional chemicals, providing a safer way to generate electricity for low-power applications.

Context

Concern about the impacts of petroleum as the world’s major energy source has driven research into alternative energy sources, such as solar radiation, wind and biomass.

One of the tools for converting these sustainable energy sources into usable forms of electricity is the fuel cell. Fuel cells are devices that use chemical reactions to change energy from one form to another.

Because of their efficiency and their ability to harvest energy from diverse sources, fuel cells show promise as one of the keys to sustainable power generation.  Fuel cell technology has already matured to the point where it can be used in power plants to supply electricity to buildings, and portable fuel cells have been demonstrated in prototype cars as well as military vehicles.  Smaller fuel cells can be used in place of batteries for electronic devices like radios or laptop computers.

A fuel cell has an anode and a cathode, just like the positive and negative terminals of a battery. Chemical reactions occur at the two electrodes.

Generally, conventional fuel cells get power from a carrier molecule – usually hydrogen – that is added to the device. The fuel cell harvests electrons from the carrier molecule, producing electrical current.  When hydrogen is used in fuel cells, it combines with oxygen in air to make water as a byproduct, also releasing heat.  Fuel cells generally do not require wind or sun and operate quietly.

Tens of thousands of scientific studies have focused on fuel cell technology in attempts to find the chemical fuels and components that produce the greatest energy efficiency. While many varieties of fuel cells have been demonstrated, one thing they have in common is that they depend on energy that was previously generated – in effect they are just tools for converting one form of energy into another. A fuel cell that consumes hydrogen generated from natural gas, for example, still depletes fossil resources. In other types of fuel cells, the carrier molecules are toxic, or the byproducts produced are harmful.  Ideally a fuel cell would derive its energy from a renewable source and avoid unsafe chemicals in the process.

To move toward this goal, there is another way to drive the reactions inside a fuel cell. This not-so-common approach is to use entropy. Entropy is a measure of disorder, and nature favors increasing disorder: it is one of the fundamental laws of thermodynamics.

What did they do?

The authors purchased a commercially available fuel cell, the kind that would ordinarily be used to harvest power from methanol, an energy carrier chemical commonly used in fuel cells. They poured water into the anode side of the cell. The cathode side was exposed to a temperature-controlled stream of air.

In the study, the pH of the water was changed by adding sulfuric acid or sodium hydroxide, and the electrical current and voltage were measured with a multimeter.  The pH was adjusted because it affects the rate at which electrons can be harvested by the cell.

What did they find?

The fuel cell was driven by evaporation of water from one end of the cell, “pulling” the chemical reactions forward. This form of entropy powered the cell.

Considering the chemical reactions involved, at one end of the cell, water breaks down to make oxygen, hydrogen ions, and electrons. At the other end of the cell, the oxygen, hydrogen ions and electrons recombine to make water. In other words, the chemical input (water) is the same as the output. The net enthalpy, or heat balance, is zero, because any heat released at one side of the cell would be balanced by an equal absorption of heat at the other side, so release of heat cannot be the driving force for the fuel cell.

However, this fuel cell used two different forms of water: liquid and vapor. Liquid water is fed into the cell and vapor escapes. Vapor is more disordered than liquid, so the entropy increases and the chemical reaction moves forward. The electrons are forced through a circuit in the process, to make electricity.

The researchers found that temperature and pH affected performance. The optimum temperature was 70 degrees celsius (about 160 degree farenheit) and the voltage was highest at pH 11 (about the same pH as household ammonia).

What does it mean?

This paper reports a unique approach in developing fuel cells. It takes advantage of the fact that a chemical reaction can be “downhill” or spontaneous even if no heat is released, as long as there is an increase in entropy.

The fuel cell design reported in this study uses this technique to drive the overall chemical reaction.

Remarkably, the fuel cell setup can be used to generate electricity from water and air, producing just water and oxygen as byproducts. This is extremely attractive compared to hydrogen, methanol or other common fuel cell chemicals that only carry energy that was generated elsewhere. For example, it is possible to derive hydrogen from solar or wind power, but in practice most hydrogen comes from natural gas or oil, and a fuel cell would only be capturing the energy from those non-renewable sources.

In addition, the use of water as the energy source avoids problems of flammability and toxicity. Many existing fuel cell technologies based on liquids have the drawbacks that the fuels, byproducts or sometimes both are very hazardous. For example, methanol fuel cells can produce formaldehyde, a cancer-causing chemical.  The authors noted that high pH gave better results; in other words the use of a pH-raising additive like sodium hydroxide would be necessary to give optimum performance.  This could be considered a drawback but it might be possible through further research to improve the reaction rate by other means.

Because evaporation of water is critical to the process, the researchers suggested that the technology would be most effective in dry, windy areas.

The main limitation of the water fuel cell is that it needs more space, and materials, to generate the same amount of power as a denser fuel cell.  The researchers suggest that the water fuel cell is perhaps 100 times less dense than would be practical for most applications. The performance, though, is similar to fuel cells that produce electricity from microbial activity. The researchers suggest the cell would be adequate to power sensors or wireless transmitters.

Further research on these fuel cells might compare the amount of energy used to construct the fuel cell and its component parts, including membranes and metal catalysts, to the amount of energy that could be generated in the fuel cell’s expected lifetime.

Resources

Demirci, UB. 2010. How green are the chemicals used as liquid fuels in direct liquid-feed fuel cells? Environment International 35:626-631.

Fuel cell basics. Smithsonian Institute.

Fuel Cell Technology Program. U.S. Department of Energy.

Tollefson, J. 2010. Hydrogen vehicles: Fuel of the Future? Nature 464:1262-1264.

Hydrogen fuel cells

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2 August High hopes in the search for clean-burning hydrogen. As General Motors gets ready to sell its new Chevrolet Volt plug-in car this year, and with Nissan right behind with its all-electric Leaf hatchback, there’s not a lot of talk about hydrogen fuel-cell cars. Toronto Star, Ontario.

28 July US seeks solar flair for fuels. The US Department of Energy has launched an ‘artificial photosynthesis’ initiative with the ambitious goal of developing, scaling up and ultimately commercializing technologies that directly convert sunlight into hydrogen and other fuels. Nature.

18 July The case of the poisoned fuel cell. Hydrogen fuel cells have their own Achilles’ heel: They are easily poisoned by carbon monoxide. Now, researchers report that they’ve created novel catalysts for fuel cell cars that strongly resist carbon monoxide contamination, potentially solving a problem that has vexed the industry for years. Science.

15 July UK firm B9 eyes hydrogen as gas plant alternative. Britain’s B9 Gas is exploring hydrogen fuel cells as an alternative cheap, low-carbon way to generate electricity instead of burning gas, the clean fossil-fuel company said on Wednesday. Reuters.

10 July UK hydrogen cars are coming – if you can fill up. Britain’s hydrogen fuel cell car fleet may hit top gear within five years, but only if there is enough investment in filling stations, the UK Hydrogen and Fuel Cells Association told Reuters on Friday. Reuters.

More news about
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New Report from Environment and Human Health, Inc: “LEED Certification Where Energy Efficiency Collides with Human Health”

LEED Certification Where Energy Efficiency Collides with Human Health, An EHHI Report

Breast Cancer, What Science Knows, What Women Think

Report Summary

Link to the Full Report

LEED Standards Are Being Adopted into Many Laws

Green Building Council standards are being incorporated into federal, state and local laws through legislation, executive orders, resolutions, policies, loan-granting criteria and tax credits. As demonstrated in this report, LEED standards are clearly insufficient to protect human health, yet they are being adopted by many levels of government as law. Thus the Green Building Council, a trade association for the building industry, is effectively structuring the regulations. The number of jurisdictions adopting these standards as law is growing, which will make them difficult if not impossible to change, unless federal law and regulation supersede the “green” standards with health-protective regulations.

No Federal Definition or Regulation of Green Building Standards

There is no federal definition of “green building standards” analogous to federal “organic food standards” or drinking water standards. Given regulatory neglect, many trade organizations have worked to create their own certification programs, hoping to capture growing demand for environmentally friendly and heath-protective buildings.

Energy Efficiency Given Priority Over Health

The LEED credit system is heavily weighted to encourage energy-efficient building performance. Nearly four times as many credits are awarded as energy conservation technologies and designs (35 possible credits) as for protection of indoor environmental quality from hazardous chemicals (8 possible credits).

Green Building Council Board Has Little Expertise in Environmental Health

Directors of the LEED Program are predominantly engineers, architects, developers, real estate executives, chemical industry officials and building product manufacturers. One medical doctor representing Physicians for Social Responsibility was recently appointed to sit on the board, which has 25 directors.

False Impression of Healthy Buildings

The Green Building Council’s award of “platinum,” “gold”, and “silver” status conveys the false impression of a healthy and safe building environment, even when well-recognized hazardous chemicals exist in building products.

Time Spent Indoors

Americans today are spending more than 90 percent of their time indoors. The EPA spends the majority of its resources working to manage outdoor threats to environmental quality and human health.

Tighter Buildings Increase Human Exposure

Energy conservation efforts have made buildings tighter, often reducing air exchange between the indoors and outdoors. Since outdoor air is often cleaner than indoor air, the reduction of outdoor-indoor exchange tends to concentrate particles, gases and other chemicals that can lead to more intense human exposures than would be experienced in better-ventilated environments.

However, the LEED program has been effective in encouraging more efficient heating and ventilation techniques, such as solar panels, geothermal wells, window placement and building orientation.

Toxic Chemicals in Built Environments

Tens of thousands of different building materials and products are now sold in global markets. Many of these products contain chemicals recognized by the U.S. National Toxicology Program, the CDC, or the World Health Organization to be hazardous.

These products include pesticides, chemical components of plastics, flame retardants, metals, solvents, adhesives and stain-resistant applications.

Some are carcinogens, neurotoxins, hormone mimics, reproductive toxins, developmental toxins, or chemicals that either stimulate or suppress the immune system.

Chemicals in Buildings Are Often Found in Human Tissues

The CDC began testing human tissues to determine the presence of some chemical ingredients of building materials. Most individuals whose tissues were tested carried dozens of these chemicals in their hair, blood or urine. Children often carry higher concentrations than adults. Chemicals released by building materials to indoor environments may be inhaled, ingested or absorbed through the skin.

No Level of LEED Certification Assures Health Protection

It is possible for new construction to be certified at the “platinum” level with no credits awarded for air quality assurance in the category “indoor environmental quality.”

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