Gregoire's CleanTech Blog

Intégration réussie d'une pile à combustible avec un système à base de méthanol reformé

Une équipe de chercheurs de l'Institut de chimie et de physique de Dalian (DICP), institut de l'Académie des sciences de Chine (CAS), a effectué d'importants progrès dans l'élaboration d'une pile à combustible 75 kW alimentée par de l'hydrogène provenant du reformage d'une solution concentrée de méthanol.
Ils ont utilisé l'hydrogène extrait du méthanol pour alimenter une pile à combustible de technologie PEMFC (Proton Exchange Membrane Fuel Cell) pour générer un courant électrique pendant trois heures consécutives. La nouveauté vient du fait que ces piles à combustible sont résistantes au monoxyde de carbone contrairement aux PEMFC actuelles.
Ce projet fait partie d'un des programmes clé d'innovation du gouvernement chinois de développer les énergies dites propres et fait du DICP une des seules organisations au monde à posséder une technologie permettant d'intégrer des sources d'hydrogène provenant du reformage catalytique du méthanol.

Source : BE Chine

Higher-Capacity Lithium-Ion Batteries

Nanostructured electrodes and active materials could shrink batteries for portable electronics and electric vehicles.

A forest of copper rods about 100 nanometers in diameter create much more surface area for high-capacity battery electrodes.

Researchers in France have created lithium-ion battery electrodes with several times the energy capacity, by weight and volume, of conventional electrodes. The new electrodes could help shrink the size of cell-phone and laptop batteries, or else increase the length of time a device could run on a charge. What's more, the nanotech methods used to make these electrodes could provide a simple and inexpensive way to structure new materials for next-generation batteries for plug-in hybrid and all-electric vehicles.

The key advance is the development of an inexpensive and simple way to organize tiny particles into a desired nanostructure, says Patrice Simon, a chemistry professor at the Université Paul Sabatier, who participated in the work along with other researchers at the university and Université Picardie Jules Verne.

In a conventional battery electrode, ions and electrons will move quickly into and out of the active material -- allowing fast charging and discharging -- only if the material is deposited in a very thin film. Thin films, however, limit the amount of active material that can be incorporated into a battery. For high-capacity batteries, engineers typically increase the thickness of the active material, trading off fast charging and high-power bursts for more energy storage.

This new nanostructure allows for both high power and high storage capacity. Active materials are applied in a very thin film to copper nanorods anchored to sheets of copper foil. This thin film allows for fast movement of ions and electrons -- providing the power. At the same time, the high surface area of the forest of nanorods makes it possible to pack much more active material into an electrode than thin films typically allow, thus increasing energy capacity. The rods provide 50 square centimeters of surface area for every square centimeter of electrode.

In addition, the high ion and electron mobility of the thin layer makes it possible to use a new active material and a new chemical reaction for lithium-ion batteries. This new chemistry is attractive because it can accommodate far more lithium ions, and their electron counterparts, than the chemistry used now, thereby potentially storing more energy.

The new electrodes, which would be used as the negative electrodes in lithium-ion batteries, also showed the ability to retain their high capacity after being charged and discharged many times, suggesting that the electrodes may have a long useable lifetime, Simon says, although more extensive tests are needed to confirm this supposition.

Because this advance, described online this week in Nature Materials, applies so far to negative electrodes, the percentage increase in capacity over today's batteries will depend on the capacity of the positive electrode as well. (See "Battery Breakthrough" for a description of one possible positive electrode candidate cited by the researchers.) The first applications of the technology will likely be extremely small batteries, Simon says. These could be useful for remote sensors or medical implants. Further applications will require increasing the size of the electrodes that the researchers can make, and also optimizing the active material they use.

The materials used in reported experiments are not energy efficient -- about 20-25 percent of the energy used to charge them cannot be recovered while discharging them. This energy loss is not a big problem with cell-phone batteries, says Gerbrand Ceder, materials science and engineering professor at MIT. "Over the lifetime you probably spend a few pennies in charging the cell phone," he says. But for larger energy applications, such as electric vehicles, this lack of efficiency could be costly, especially with high electricity prices. For this reason, the researchers are incorporating different high-capacity active materials into their nanostructured electrodes that do not have this energy efficiency problem.

In turning to nanotechnology to improve batteries, the French researchers are not unique. At least two companies, A123 Systems, in Watertown, MA, and Altair Nano, in Reno, NV, have made batteries that include electrodes with nanostructured active materials; and numerous research groups around the world are developing such electrodes. Simon describes his group's process as being simpler and cheaper than many other methods for making nanostructures. It is also versatile, capable of being used with a variety of active materials, he says.

It could also be important for another key trend in battery research: the move away from flat layers of electrode materials to positive and negative electrodes that interpenetrate -- a three-dimensional architecture that can improve the mobility of ions and electrodes, thereby increasing battery power. The French group is also now working on a three-dimensional battery, says Simon, that will combine their negative electrodes with a high-performance positive electrode.

By Kevin Bullis

Source : Technology Review

Seven Participants Complete Negotiations for International Fusion Reactor

The research ministers of the seven international parties engaged in the $10 billion ITER fusion project have met in Brussels to confirm the agreements negotiated over the past year, following the selection of the construction and operation site at Cadarache in southern France (see Superconductor Week, Vol 20, No. 12).  Since the decision last June to locate the project at Cadarache, the seven parties (the EU, Russia, Japan, China, India, South Korea and the U.S.) have been working on agreements that would bring to an end a complex — and at times acrimonious — three year long negotiation process.  Now each partner in the project must confirm the adoption of the agreement according to laws and practices of their respective governments.

For the EU, the host and largest financial contributor to ITER, this means that the Council of Ministers will be asked to adopt a decision endorsing the agreement.  The EU is represented by the EURATOM Community.  ITER’s Director General, Kaname Ikeda, hopes all parties will have completed the process by the end of 2006, which, in tandem with the completion of the process of gaining all necessary construction permits at the site, will mean actual construction can start in 2007.

“This is a truly crucial moment, for the ITER project and for global scientific co-operation in general,” said European Science and Research Commissioner Janez Potocnik, who hosted the meeting. “Together we are forging a new model for large-scale global scientific and technical cooperation.”

EU will provide 40% of the 5 billion euro ($6.4 billion) construction costs for ITER, with the other partners paying approximately 10% each.  The EU is also paying 26 percent of the 5 billion euro operating costs.

In other news in the fusion effort, and paralleling the international progress in pursuit of the world’s largest fusion project, the Institute of Plasma Physics at Hefei, under the Chinese Academy of Sciences (CAS), has successfully completed the first tests of the Experimental Advanced Superconducting Tokamak (EAST) fusion experiment.  The final assembly of the device is complete, and it is now undergoing vacuumizing, cooling, and galvanizing experiments.  The first plasma discharge is scheduled for July or August.

EAST started overall assembly in 2003, and was developed as an upgrade from HT-7, China’s first superconducting tokamak completed in 1990.  The budget for the device was just 300 million yuan ($37 million) — a small fraction of the cost of the multi hundred million dollar price tag of similar devices being developed elsewhere.   

If the device succeeds, China will become the first country to build and successfully demonstrate a superconducting tokamak fusion device.  The goals for EAST include exploring and demonstrating steady-state operation of a tokamak and generating plasma currents of 1MA.  With a capability for pulse times as long as 1,000 seconds, the device will also be used to investigate particle and heat flux handling on a time scale much longer than the wall equilibration time.

“The EAST project research results will be significant for the International Thermonuclear Experiment Reactor, or ITER, in terms of basic research both in engineering technology and physics,” said Wan Yuanxi, General Manager of EAST. “The technology developed for EAST will allow fabrication of ITER parts in China.”

India, the most recent addition to the ITER partnership, has been awarded the critical role of building the cryostat (refrigeration enclosures for the superconducting magnets used in the devices) for the massive device.  China is moving ahead with large-scale fusion research projects on a number of fronts.  Fusion may or may not prove to be a technologically feasible source of virtually endless energy, but I am continually amazed at the energy and sacrifice that poorer nations are capable of in pursuit of alternative ways to fuel their growth, environmental stability, and energy security.

Mark Bitterman, Executive Editor, Superconductor Weekhttp://www.superconductorweek.com

Ten ways to save gasoline and diesel

Hydrogen Nano-sensors in Speed Race

It is good to see an environmental sensor company go public (Tiger Optics); however, I must concede that I expect a lag of a year or two in the sensor IPO activity I predicted in my Clean Technology Trends for 2006 blog.

Of particular interest is the number of companies likely to commercialize sensors based on nanotechnology in the 2007/8 timeframe. A clear R&D target is sensors for hydrogen detection, a function in high demand as we use more hydrogen to power our economy. Here are some promising hydrogen nano-sensor technologies receiving attention this month.

Palladium Plays

Applied Nanotech’s metal nanoparticle sensor (MNPS) — films of metal nanoparticle alloys — detects hydrogen gas, CO and other gases, as well as chemicals.  MNPS technology has not been widely used in sensors. By using palladium particles to dissociate and dissolve hydrogen as small as parts per million, ANI’s technology is demonstrating response times of two seconds. Applied Nanotech is part of the intellectual property portfolio of Nano-Proprietary, Inc. (OTC Bulletin Board: NNPP), and is certain to be spun off at some point.

This palladium hydrogen nano-sensor has been perking up the fuel cell world this week. Yokohama National University is using palladium dust in an ultra-sensitive sensor that detects hydrogen gas in under one second, and in amounts as small as 100 parts per million.

Acoustics

A NASA-funded project at the

University

of

Florida

has developed a hydrogen sensor that claims to have solved the hydrogen storage paradox, although its technology is a mystery of its own.  It apparently “draws its power from a tiny internal source that harvests energy from small vibrations.”  A Space Daily article goes on to say the sensor can operate continuously without batteries off the slight vibrations of pumps and cars.  When hydrogen is detected, alarms sound through a wireless network.

If any one knows more about the “tiny internal source,” please let us know.  It sounds like nanotechnology and acoustics.  Applied Nanotech is also developing a photo-acoustic sensor.  Do not underestimate acoustic technology.  We are just beginning to rediscover what we once knew.  It is now believed that acoustic vibrations moved the mammoth stones that built the Egyptian pyramids.

Cavity Ring-Down Spectroscopy (CRDS)

Cavity “ring-down” spectroscopy sounds like acoustics.  It is the photonic technology applied by Tiger Optics to detect trace gases, including hydrogen, at fast speeds and highly sensitive levels. CRDS technology is based on the familiar semiconductor laser, with a few tricks and mirrors (Here is a good overview of CRDS technology).  One of the few other companies in this space is Picarro, a Stanford spin-off.  CRDS is not a nanotechnology, but a proven photonic technology whose potential is just beginning to be tapped, particularly in new laser architectures. It would be interesting to know how the CRDS laser performs in hydrogen detection relative to the emerging nanotechnologies; perhaps Rob Day over at Expansion Capital Partners can shed some light on this.

Lien: EcoLog :: Hydrogen Nano-sensors in Speed Race.

Large-Scale, Cheap Solar Electricity

A well-financed California startup is promising to build a solar-cell factory that could finally make solar power affordable.

Part of a solar-cell printing machine in Nanosolar’s pilot manufacturing plant. The technology might make solar power competitive with electricity from the grid. (Courtesy of Nanosolar.)

This week, Nanosolar, a startup in Palo Alto, CA, announced plans to build a production facility with the capacity to make enough solar cells annually to generate 430 megawatts. This output would represent a substantial portion of the worldwide production of solar energy.

According to Nanosolar's CEO Martin Roscheisen, the company will be able to produce solar cells much less expensively than is done with existing photovoltaics because its new method allows for the mass-production of the devices. In fact, maintains Roscheisen, the company's technology will eventually make solar power cost-competitive with electricity on the power grid.

Nanosolar also announced this week more than $100 million in funding from various sources, including venture firms and government grants. The company was founded in 2001 and first received seed money in 2003 from Google's founders Larry Page and Sergey Brin.

Experts say Nanosolar’s ambitious plans for such a large factory are surprising. "It's an extraordinary number,” says Ken Zweibel, who heads up thin-film research at the National Renewable Energy Laboratory in Golden, CO. Most groups building new solar technologies “add maybe 25 or 50 megawatts," he says. "The biggest numbers are closer to 100. So it's a huge number, and it's a huge number in a new technology, so it's doubly unusual. All the [photovoltaics] in the world is 1,700 megawatts."

Today, the lion's share of solar cells are based on crystalline silicon, which is about three to five times too costly to compete with grid electricity, Zweibel says.

Nanosolar's technology involves a thin film of copper, indium, gallium, and selenium (CIGS) that absorbs sunlight and converts it into electricity. The basic technology has been around for decades, but it has proven difficult to produce it reliably and cheaply. Nanosolar has developed a way to make these cells using a printing technology similar to the kind used to print newspapers, rather than expensive vacuum-based methods.

Although the company expects to start selling solar cells next year, ramping up to full production will take more time. Meanwhile, high demand for solar cells worldwide will keep prices high, Roscheisen says. Eventually, however, he says the company hopes to attract more customers with lower prices, in several years reaching prices that make solar-power electricity competitive with the grid.

Zweibel says the company is likely to face challenges in ramping up production, although their pilot manufacturing facility is a big step. And he adds that Nanosolar is not alone in developing inexpensive manufacturing processes for CIGS solar cells, and at least one other company is working with a printing process.

Meanwhile, Andrew Gabor, senior engineer at Evergreen Solar, a silicon solar-cell developer and manufacturer in Marlboro, MA, says current supply problems related to conventional solar cells are easing as more production capacity is coming on line. This could mean that prices for silicon cells start dropping again, eventually becoming competitive with grid electricity. He suggests that in the future solar electricity supply will likely be met by a mix of technologies.

By Kevin Bullis

Source : Technology Review

La technologie biodiesel reçoit le prix finlandais de l'innovation

La technologie NExBTL de Neste Oil qui permet la production de biodiesel à partir d'huile végétale et de matières grasses animales a reçu un prix finlandais de l'innovation d'un montant de 20.000 euros de la part de la fédération des industries chimiques.
L'usine de production ouvrira ses portes pendant l'été 2007 et sera située sur le site de la raffinerie de Neste Oil à Porvoo. Cette technologie est pour l'instant unique et contribue aux objectifs fixés par l'Union européenne, soit 5,75% de biocarburants d'ici à 2010.
Le carburant obtenu par ce procédé peut être utilisé tel quel pour des véhicules ou en mélange avec du diesel normal. En mélange, le biodiesel contribue à la réduction des émissions NOx des pots d'échappements des véhicules.
Neste oil négocie actuellement la construction d'usines basées sur cette technologie en Autriche et en France.

Source : BE Finlance

An Alternative to your Alternator

New thermophotovoltaic materials could replace alternators in cars and save fuel.

A "thermophotovoltaic" (TPV) generator burns fuel to heat a material that emits light (labeled "radiator"). The light is then filtered and converted into electricity in photovoltaic (PV) cells. (Image courtesy of John Kassakian, MIT.)

Researchers at MIT are developing new technology for converting heat into light and then into electricity that could eventually save fuel in vehicles by replacing less-efficient alternators and allowing electrical systems to run without the engine idling.

The technology, called thermophotovoltaics, uses gasoline to heat a light-emitting material, in this case tungsten. A photovoltaic cell then converts the light into electricity. The idea has been around since the 1960s, says John Kassakian, MIT electrical engineering and computer science professor. But until now, the light emitters for the photovoltaics produced inefficient and very costly systems. Improvements in the materials used in these latest devices -- possible in part because researchers can modify the material structure at the nanoscale -- are now making much more efficient systems, Kassakian says.

According to Kassakian, the system could potentially be a more efficient way to power electrical systems in a vehicle than the current alternator-based one, which wastes energy in two stages: the internal combustion engine converts only about 30 percent of the energy in fuel into movement, and then the alternator is only 50 percent efficient in converting the mechanical energy into electricity. He says a small prototype thermophotovoltaics device that could confirm the system's improved efficiency might be ready in a year.

The researchers modified the surface structure of the light emitter, etching into it nano-sized pits to tune the wavelengths of light emitted to precisely those a photovoltaic cell can convert most efficiently into electricity. They further refined the device with the use of filters that allow the desired wavelengths of light to pass through to the photovoltaic cells, but reflect other wavelengths back to the light emitter. The reflected light carries energy that helps keep the emitter hot, reducing the amount of fuel needed.

In addition to replacing the alternator with a thermophotovoltaic module, says Kassakian, the technology could be part of an air-conditioning system for vehicles that doesn't require a compressor. Because this would significantly decrease the load on an engine, it could make it possible to turn off the engine when the vehicle stops in traffic and easily restart it. Today's hybrids use this technique to save gas, but require large batteries to provide electricity for the radio and lights, and to restart the engine, and they have to turn the engine back on when the battery charge runs out. In the new MIT system, these batteries wouldn't be necessary.

Indeed, if the new materials do make more efficient thermophotovoltaics, there will be no shortage of potential uses. Kassakian says a particularly good application, when combined with the a new air-conditioning system, could be for use in trucks with sleeper cabs to cool the cabs and provide electricity for televisions and other equipment. And, says Donald Chubb, a researcher at the NASA Glenn Research Center, "The military has had a lot of interest in it for portable power supplies in the field. Because there are no moving parts, there wouldn't be any noise, so you couldn't detect it."

It will be several years before the technology can used in vehicles, though. Challenges include scaling up the fabrication process, developing effective insulation and cooling systems to manage the heat generated, and ensuring that the system remains efficient on a larger scale. The MIT research is funded in part by Toyota, but the automaker has not committed to implementing the technology.

By Kevin Bullis

Source : Technology Review