In a step toward using gas hydrates as a future energy source, researchers in New York are reporting the first identification of an optimal temperature and pressure range for maximizing production of natural gas from the icy hydrate material. Their study appears in the March 18 issue of ACS’ Industrial & Engineering Chemistry Research, a bi-weekly journal.

Marco Castaldi, Yue Zhou, and Tuncel Yegualp note that gas hydrates, also known as “ice that burns,” are a frozen form of natural gas (methane). This material exists in vast deposits beneath the ocean floor and Arctic permafrost in the United States and other areas. Scientists believe that fuel from these frozen chunks, formed at cold temperatures and high pressures, may help fuel cars, heat homes, and power factories in the future. Although scientists have identified several different methods for extracting the fuel, including depressurization, researchers have not found an practical approach for producing the gas on an industrial scale.

To reach this goal, the researchers built what they believe to be the world’s largest experimental reactor, filled with sand, water, and methane, to simulate the formation gas hydrates (at low temperatures and high pressure) and production of the gas. While depressurizing the hydrates to free the methane, they observed an optimal boost in gas production between a narrow range of temperatures and pressures. Maintaining gas production at these settings could be a key step in boosting production of methane at an industrial scale, the researchers suggest. – MTS

“Experimental Investigation of Methane Gas Production from Methane Hydrate”

DOWNLOAD FULL TEXT ARTICLE:http://pubs.acs.org/stoken/presspac/presspac/full/10.1021/ie801004z

They are at present the most accurate clocks in the world: Caesium fountain clocks furnish the second accurate to 15 places after the decimal point. Until they reach this accuracy, caesium fountain clocks, however, need a certain measurement time. This time has now been considerably reduced with the aid of a new method developed at the Physikalisch-Technische Bundesanstalt (PTB) which makes the output frequency of the caesium fountains more stable. For excitation of the caesium atoms, the PTB physicists make use of a novel microwave source: they replace the oscillating quartz by a microwave oscillator which has been stabilized with the aid of a laser to such an extent that its noise becomes insignificant for fountain operation. For this purpose, techniques were applied which have originally been developed for optical atomic clocks which are regarded as the atomic clocks of the future. Now these previous competitors can complement one another, and the technology of the optical clock leads to a considerable improvement of the established caesium clocks. The results are currently published in the journal Physical Review A.

Caesium fountains are more accurate than “normal” atomic caesium clocks, because in fountains the caesium atoms are cooled down with the aid of laser beams and come ever slower – from a rapid velocity at room temperature to a slow “creep pace” of a few centimetres per second at a temperature close to the absolute zero point. Thus, the atoms remain together for a longer time so that the physicists have considerably more time to measure the decisive property of the caesium atoms which is required for the “generation of time”: their resonance frequency. When a maximum of atoms has changed into an excited state, the frequency of the exciting signal is measured – those approximately nine billions of microwave oscillations which must elapse until exactly one second has past.

In this way, the second has been defined in the International System of Units, SI. Realization of the second is achieved the more accurate, the finer the frequency of the microwave signal is tuned to the resonance frequency of the atoms and the lesser the microwave signal varies around the optimal value. This noise is considerably reduced with the aid of the new technique.

The new technique no longer employs an oscillating quartz for microwave generation, but a microwave oscillator which can be excellently stabilized with the aid of extremely stable lasers. For this purpose, a so-called optical comb is used – a technique which has been developed for the establishment of optical atomic clocks. In the case of these atomic clocks, no microwave transitions, but optical transitions with frequencies five orders of magnitude above the microwave frequencies are used. For their well-aimed excitation, these transitions require extremely low-noise laser light which is generated with the aid of lasers which have been stabilized to special high-quality resonators. For measurement, the frequency of this laser light can be converted with the aid of the optical comb into microwave or low-frequency oscillations which finally allow the second pulses to be generated.

For use with a fountain, the microwave oscillator – which has been pre-stabilized by the highly stable laser and the optical comb – is slowly readjusted by the fountain output signal (like formerly the quartz oscillator). The results so far achieved show an improvement of the relative frequency instability by approximately 50% which leads to a reduction in the measurement times by a factor of 3.2. Instead of in three days, a measurement can then, for example, be performed in one day. The experiments show without a doubt that the microwave oscillator stabilized by the laser does no longer furnish any noise contribution so that the quantum projection noise limit has been reached. This noise is given by the quantum nature of the caesium atoms. This is caused by the fact that in clock operation, the atoms can never definitely change into the excited state, but that this always happens with a certain probability which leads to a noise contribution: the quantum projection noise.

The results clear the way for further improvements of the instability by increasing the atomic numbers used in the fountain clock. Improved instabilities are not only favourable as regards the required measurement times, but also allow systematic frequency-shifting effects to be investigated in closer detail. They are, therefore, also indispensable for future reductions in the overall uncertainty of the clock. This allows a fruitful interaction: while the fountains benefit from the technology of the optical clocks, the development of the latter benefits from the more exact fountain clock as an improved reference.

Source: Physikalisch-Technische Bundesanstalt (PTB)

Last summer, it was very expensive to fill up a gas tank when the gasoline price hit close to four dollars a gallon. Transportation by road or air consumes fuel, which not only increases our vulnerability to foreign imports but also is a source of greenhouse gas emissions that will impact adverse change in climate and global warming. A mechanical engineer at Washington University in St. Louis is developing techniques that will lessen our monetary pain at the pump by reducing the drag of vehicles. Drag is an aerodynamic force that is the result of resistance a body encounters when it moves in a liquid or gaseous medium (such as air). Reduction in drag means less fuel would be required to overcome the fluid resistance encountered by the moving vehicle.

Working with undergraduate and graduate students, Ramesh K. Agarwal, Ph.D, the William Palm Professor of Engineering at Washington University in St. Louis, has successfully demonstrated that the drag of airplane wings and cars/trucks can be reduced by employing the active flow control (AFC) technology. The idea behind the AFC is to deploy actuators on the surface of these vehicles to modify the flow in a way that the overall resistance is reduced. Using computational fluid dynamics software, Agarwal has found that the actuators modify the flow, which results in drag reduction, which in turn reduces the fuel amount needed.

“The most promising actuators are the so called synthetic jet or oscillatory jet actuators which are embedded in the surface of the body (an airplane wing for example), and essentially perform injection and suction of the fluid from the surface in a periodic manner,” said Agarwal. He has demonstrated that the transonic drag of an airplane wing can be reduced by 12 to 15 percent with the incorporation of three-ounce actuators, about 20 to 30 spaced optimally on the surface of the wing.

“We use the genetic algorithms and artificial neural net algorithms to optimize the placement of actuators.” Agarwal said. His students have recently applied the concept on cars and trucks and have achieved 15 to 18 percent reduction in drag by placing the actuators on the back surface of these vehicles. Although the technology has not yet been deployed on any commercially available vehicle, it is being researched and investigated by airplane and automobile companies worldwide.

“There are approximately 100 million cars and trucks on the road in the United States alone and hundreds of millions more worldwide. Similarly there will be a substantial increase in air transportation worldwide. The AFC technology can therefore play an important role in fuel conservation and reduction of greenhouse gas emissions,” said Agarwal, one of the most decorated engineers in the United States and a fellow of ten national science and engineering societies including the American Association for Advancement of Science, American Physical Society, American Society of Mechanical Engineers (ASME), American Institute of Aeronautics and Astronautics (AIAA) and the Institute of Electrical and Electronics Engineers.

Agarwal will receive the James B. Eads Award from the Academy of Science of St. Louis on April 30, 2009. It is the latest of several distinguished awards he has received in just the past three years. An internationally renowned scholar who is considered a leading authority in aerodynamics and computational fluid dynamics, he has been the recipient of almost all the major national and international awards in these fields.

In 2007, he received the Gold Award from the Royal Aeronautical Society of U.K., an award given to fewer than five Americans in more than fifty years. In 2008, he received the “Aerodynamics Award” for outstanding contributions to Aerodynamics; it is the highest national award given by the AIAA in Aerodynamics. In 2008, he was also the recipient of William Littlewood Award given jointly by AIAA and SAE (Society of Automotive Engineers). Established in 1971, the award has only been given twice to a member of academia including Agarwal. It is normally given to CEOs and senior executives of aerospace companies worldwide. He received the “Fluids Engineering Award” in 2001 from ASME, the highest national technical award given by ASME in fluid dynamics.

Agarwal is also working for the United States Air Force on development of techniques to predict heat transfer and to design improved thermal protection systems for the next generation of space access vehicles.

Source: Washington University in St. Louis

Millions of homes in rural areas of Far Eastern countries are heated by charcoal burned on small, hibachi-style portable grills. Scientists in Japan are now reporting development of an improved “biomass charcoal combustion heater” that they say could open a new era in sustainable and ultra-high efficiency home heating. Their study was published in ACS’ Industrial & Engineering Chemistry Research, a bi-weekly journal.

In the study, Amit Suri, Masayuki Horio and colleagues note that about 67 percent of Japan is covered with forests, with that biomass the nation’s most abundant renewable energy source. Wider use of biomass could tap that sustainable source of fuel and by their calculations cut annual carbon dioxide emissions by 4.46 million tons.

Using waste biomass charcoal, their heater recorded a thermal efficiency of 60-81 percent compared to an efficiency of 46-54 percent of current biomass stoves in Turkey and the U.S. “The charcoal combustion heater developed in the present work, with its fast startup, high efficiency, and possible automated control, would open a new era of massive but small-scale biomass utilization for a sustainable society,” the authors say.

Source: American Chemical Society.

Discarded electronic hardware, including bits and pieces that built the information superhighway, can be recycled into an additive that makes super-strong asphalt paving material for real highways, researchers in China are reporting in a new study. It is scheduled for the Feb. 1 issue of ACS’ Environmental Science & Technology, a semi-monthly journal. They describe development of a new recycling process that can convert discarded electronic circuit boards into an asphalt “modifier.” The material makes high-performance paving material asphalt that is cheaper, longer lasting, and more environmentally friendly than conventional asphalt, the scientists report.

In the new study, Zhenming Xu and colleagues note that millions of tons of electronic waste (e-waste) pile up each year. The printed circuit boards used in personal computers, cell phones, and other electronic gear, contain toxic metals such as lead and mercury and pose a difficult disposal problem. The boards also are difficult to recycle. Xu’s group, however, realized that the boards, which provide mechanical support and connections for transistors and other electronic components, contain glass fibers and plastic resins that could strengthen asphalt paving.

The scientists describe a new recycling method that quickly separates toxic metals from circuit boards, yielding a fine, metal-free powder. When mixed into asphalt in laboratory tests, the powder produced a stronger paving material less apt to soften at high temperatures, the researchers say. -MTS

Source: Shanghai Jiao Tong University, Shanghai, China.

It was the geological collision between India and Asia millions of years ago that created one of the world’s most distinctive places: The area around Lake Baikal in Siberia, which contains 20 per cent of the world’s fresh water reserves and a unique display of plant- and wildlife.

That is the conclusion reached by two Danish researchers from the University of Copenhagen, Professor Hans Thybo and PhD Christoffer Nielsen, after many seismic examinations, including blowing up tons of dynamite, and five years work of analyzing the data.

In the middle of Siberia lies the 2000km long Baikal Rift Zone, where, over the last 35 million years, a gigantic crack in the Earth’s crust has developed. In the middle of this rift zone lies the world’s deepest lake, Lake Baikal, which is almost 1700m deep. Due to Lake Baikal’s isolated location, far from the world’s oceans the microbial and animal life found here has undergone a unique evolution over the last 30 million years. The Baikal Rift Zone, or fracture zone, is also special because it is located 3000km away from the nearest tectonic plate boundary. Therefore, it has been difficult, until now, to explain the origin of the Baikal Rift Zone using commonly accepted geological premises and methods.

However, two Danish researchers from the University of Copenhagen in collaboration with Eastern European colleagues, have succeeded in uncovering what happened, and what is still happening, under the surface of one of the most special and distinctive areas on Earth. More than that; the results from the experiment in Siberia have lead to a new understanding of, and model for, the formation of and activity in rift zones, which are found in locations around the globe, including between the continents.

Lots of dynamite

In Siberia the Danish research team lead a seismic experiment known as BEST (Baikal Explosion Seismic Transects) carried out around Lake Baikal. The experiment included setting off of tons of dynamite so the scientists could follow the sound waves from the explosion as they traveled through the ground, using them to determine the structure of the Earth’s crust and the upper mantle and thus gain an understanding of the processes driving the rift zone’s development.

The fieldwork at Lake Baikal was carried out in 2003-2004 with financial support from the Carlsberg Foundation and the Danish Natural Science Research Council and in collaboration with geologists and geophysicists from the Russian Academy of Science’s Siberian departments and the Polish Academy of Science. Since then the scientists have spent 5 years interpreting the huge amount of data they collected and have ended up with sensational seismic results related to the general formation of, and activity in, rift zones around the world.

The sensational results from Siberia now form the basis for a new model for understanding the formation of rift zones on a global plan. The results from Lake Baikal show that the 40-50km wide crack in the Earth’s crust is around 10km deep. All previous models of rift processes have assumed that the bottom of the Earth’s crust would have a corresponding bulge. However to the researchers’ great surprise it turned out that the bottom of the crust is flat across Lake Baikal.

The two scientists explain this phenomenon by a greater thinning of the crust than expected but at the same time also by an intrusion of magma (liquid rock from the Earth’s mantle) into the bottom part of the crust layer. The volume of the magma corresponds to the thinning of the crust.

The research group has therefore reinterpreted data from a number of other rift zones around the globe, including from the East African rift in Kenya where Karen Blixen had her African farm and from an older rift zone in the Ukraine. In both places the researchers see the same phenomenon found in Siberia. This is an important reason for the Danish researcher’s new results.

Rift zones can divide continents

Rift formation is a fundamental process of plate tectonics, which can, given time, split a continent in two. Up until 60 million years ago, what is currently Europe and North America was one large continent. The northern Atlantic appeared when a rift zone developed between what is now Norway and Greenland. The rifting process continued and ca 55 million years ago a new ocean arose.

Rift zones are also important for oil exploration as many oil rich areas have arisen as a result of rift processes. This is true, for example, of the area around the Central Graben in the North Sea which is a former rift zone whose development halted. The Central Graben is the location where the countries bordering the North Sea obtain most of their oil. It is therefore important to understand the processes that lead to rift formation, as it may give us an opportunity to pump more oil up from underground.

Source:University of Copenhagen.

Now a Northwestern University-led research team has identified a promising new material that could transform a technology that currently cools and heats car seats — thermoelectrics — into one that also efficiently converts waste heat into electricity to help power the car and improve gas mileage.

The researchers discovered that adding two metals, antimony and lead, to the well-known semiconductor lead-telluride, produces a thermoelectric material that is more efficient at high temperatures than existing materials. The results are published online in the journal Angewandte Chemie.

“We cannot explain this 100 percent, but it gives us a new mechanism — and probably new science — to focus on as we try to raise the efficiency of thermoelectrics,” said Mercouri G. Kanatzidis, Charles E. and Emma H. Morrison Professor of Chemistry in the Weinberg College of Arts and Sciences and the paper’s senior author.

Current thermoelectric technology is only used in niche markets, such as solid-state refrigeration and cooling, because the materials are not very efficient. With new materials and increased efficiency, devices based on thermoelectrics could find widespread use in the automotive industry, solar energy conversion and the conversion of waste heat from nuclear reactors, smokestacks and industrial equipment.

“It’s a big accomplishment to recover some of the heat or energy that would otherwise be lost and convert it into useful energy,” said Kanatzidis. “That’s what thermoelectrics can do, but we need to make them more efficient to really be practical.”

Thermoelectric materials are only 5 to 6 percent efficient today, but a new generation of materials based on recent discoveries including this one at Northwestern, could produce devices with 11 to 14 percent efficiency, says Kanatzidis. The long-term goal is to reach 20 percent.

Thermoelectric materials convert heat into electricity by taking advantage of temperature differences. Electrons move from the hot end of the material to the cold end, creating positive and negative electrodes and an electrical voltage.

A thermoelectric device, for example, could be attached to a car’s tailpipe. The side of the material in contact with the tailpipe would be the hot side, and the side exposed to the air would be the cold side. The temperature difference would be enough to generate electricity, which would be returned to the car’s engine for additional torque. Such devices also could be used in large industrial plants, such as those for power, chemical production and glass making.

Car companies are working on the thermoelectrics problem as part of their strategy to raise the overall gas mileage of vehicles, says Kanatzidis. They hope to raise mileage by 5 to 10 percent per gallon using thermoelectrics, which would be significant.

A superior thermoelectric material needs to have these properties to work: high electrical conductivity (to transfer a lot of power), low thermal conductivity (to maintain the temperature difference and prevent equilibrium) and the ability to generate a large voltage for as small a temperature difference as possible.

A material with all three properties is difficult to find, but Kanatzidis and his team found it — in an unexpected way.

Four years ago, Kanatzidis and his research group discovered a class of materials based on lead-telluride that doubled the efficiency performance of existing materials. They were able to lower the thermal conductivity without changing its electrical properties by putting nanodots — small particles of silver-antimony-telluride between two and 10 nanometers in diameter — inside the lead-telluride.

For the new work reported in Angewandte Chemie, Kanatzidis and graduate student Joseph Sootsman decided to add two different materials — the metals lead and alimony, also in the form of nanodots — to lead-telluride to see if they could lower the thermal conductivity even more. They were surprised when they saw the results.

“The thermal conductivity was not any lower than our earlier results, but we discovered a net gain in electrical conductivity at high temperatures that we didn’t expect,” said Kanatzidis. “This means we had a net gain in power coming out of the material that we didn’t have before. This was very surprising.”

Interestingly, the researchers also discovered that adding lead or antimony alone to the lead-telluride did not produce an improvement. Lead and antimony both had to be present in the lead-telluride to produce the electrical conductivity gain. The electrons scatter less and move faster with the two inclusions than with just one or none.

“This phenomenon will stimulate new scientific inquiries and generate new ideas on how to design even more efficient thermoelectric materials in the future,” said Kanatzidis.

Source: Northwestern University.

The new map design follows a series of historical and ongoing arguments about ownership, and the race for resources, in the frozen lands and seas of the Arctic.

The potential for conflicts is increasing as the search for new oil, gas and minerals intensifies.

The move to comprehensively map the region illustrates the urgent need for clear policy-making on Arctic issues – an area rich in natural resources. The Durham map shows (click here to view the map):

1. where boundaries have been agreed
2. where known claims are
3. the potential areas that states might claim

Director of Research at the International Boundaries Research Unit (IBRU), Martin Pratt says: “The map is the most precise depiction yet of the limits and the future dividing lines that could be drawn across the Arctic region.

“The results have huge implications for policy-making as the rush to carve up the polar region continues.

“It’s a cartographic means of showing, and an attempt to collate information and predict the way in which the Arctic region may eventually be divided up. The freezing land and seas of the Arctic are likely to be getting hotter in terms of geopolitics; the Durham map aims to assist national and international policy-makers across the world.”

It’s a year since Russia planted a flag on the seabed, underneath the North Pole, highlighting its claim to a huge chunk of the Arctic.

The Russian demands relate to a complex area of law covered by the United Nations Convention on the Law of the Sea Convention (UNCLOS). Under that law, any coastal state can claim territory 200 nautical miles (nm) from their shoreline (Exclusive Economic Zone, EEZ) and exploit the natural resources within that zone. Some coastal states have rights that extend beyond EEZ due to their continental shelf. Areas of the seabed beyond the continental shelf are referred to as ‘The Area’ and any world state – landlocked or not – has equal rights in this area.

The continental shelf is the part of a country’s landmass that extends into the sea before dropping into the deep ocean. Under UNCLOS, if a state can prove its rights, it can exploit the resources of the sea and the seabed within its territory.

Russia claims that its continental shelf extends along a mountain chain running underneath the Arctic, known as the Lomonosov Ridge. Theoretically, if this was the case, Russia might be able to claim a vast area of territory.

The IBRU map shows what is currently possible and what might be permissible in terms of territorial claims under international law. It also highlights the areas of land and sea where clashes of interest are likely.

A new survey by the US Geological Survey estimates that a fifth of the world’s undiscovered, technically-recoverable resources lie within the Arctic Circle. The Lomonosov Ridge is just one area of contention between countries. Other disputes involve Canada, USA, (Greenland) Denmark, Iceland and Norway.

The problem with claims is that they must be verified by geological, geomorphological and bathymetric analysis (sub-sea surveys), and it’s not an easy or quick process to verify claims.

The new map will help politicians to understand areas of maritime jurisdiction and the methodology employed could be vital in helping to settle future sea territorial disputes.

Conservationists want laws to protect the North Pole region and climate change is likely to bring further pressure as ice melts and the seas open up to exploration.

Source: Durham University.

The journal paper, ‘Cow Power: The Energy and Emissions Benefits of Converting Manure to Biogas’, has implications for all countries with livestock as it is the first attempt to outline a procedure for quantifying the national amount of renewable energy that herds of cattle and other livestock can generate and the concomitant GHG emission reductions.

Livestock manure, left to decompose naturally, emits two particularly potent GHGs – nitrous oxide and methane. According to the Intergovernmental Panel on Climate Change, nitrous oxide warms the atmosphere 310 times more than carbon dioxide, methane does so 21 times more.

The journal paper creates two hypothetical scenarios and quantifies them to compare energy savings and GHG reducing benefits. The first is ‘business as usual’ with coal burnt for energy and with manure left to decompose naturally. The second is one wherein manure is anaerobically-digested to create biogas and then burnt to offset coal.

Through anaerobic digestion, similar to the process by which you create compost, manure can be turned into energy-rich biogas, which standard microturbines can use to produce electricity. The hundreds of millions of livestock inhabiting the US could produce approximately 100 billion kilowatt hours of electricity, enough to power millions of homes and offices.

And, as manure left to decompose naturally has a very damaging effect on the environment, this new waste management system has a net potential GHG emissions reduction of 99 million metric tonnes, wiping out approximately four per cent of the country’s GHG emissions from electricity production.

The burning of biogas would lead to the emission of some CO2 but the output from biogas-burning plants would be less than that from, for example, coal.

Authors of the paper, Dr. Michael E. Webber and Amanda D Cuellar from the University of Texas at Austin, write, “In light of the criticism that has been levelled against biofuels, biogas production from manure has the less-controversial benefit of reusing an existing waste source and has the potential to improve the environment.

“Nonetheless, the logistics of widespread biogas production, including feedstock and digestates transportation, must be determined at the local level to produce the most environmentally advantageous, economical, and energy efficient system.”

Source: Institute of Physics.

The automaker said today its first FCX Clarity hydrogen fuel cell-powered vehicle will roll off the assembly line next month, and go only to pre-selected customers for now. Honda also revealed the first auto dealership network in the United States to sell and service the next-generation cars. All three are located in California, Power Honda Costa Mesa, Honda of Santa Monica, and Scott Robinson Honda in Torrance.

The announcements were made during a ceremony for the start of FCX Clarity production at the world’s first dedicated fuel cell vehicle manufacturing facility in Japan.

Honda previously announced plans to deliver about 200 FCX Clarity hydrogen fuel cell-powered vehicles in the U.S. and Japan to customers in the first three years of production, with leases beginning in July. The lease program marks the world’s first large-scale retail initiative for fuel cell vehicle technology.

The FCX Clarity is a next-generation, hydrogen powered fuel cell-powered vehicle. Propelled by an electric motor that runs on electricity generated in the fuel cell, the vehicle’s only emission is water, and its fuel efficiency is three times that of a modern gasoline-powered automobile.