The math and commentary have been published in the August 10th issue of the ACS journal Energy & Fuels. The news, a bit obtuse this writer will admit, is still quite significant.  Coverage is worldwide if seemingly subdued – there aren’t a lot of journalists that are going to realize the significance of reducing the catalyst needs by factors in the 4 to 8 range.

Fractal Branched Fuel Cell Layout. Click image for more info.

It’s still theory for now, using sophisticated math for getting to the point. Stay with me: the process method uses the theorem of equipartition of entropy production to maximize energy efficiency.  The gas supply and water outlet systems, designed to produce entropy uniformly, have a fractal structure inspired by the human lung. The tree-like gas distributor engraved in the fuel cell bipolar plates may eliminate the need for porous transport layers.

Mathematical solutions are provided for the optimal height, macroporosity, and nanoporous column width of the electro-catalytic layer beneath the gas supply system.  The paper shows that the optimal macroporosity of the catalytic layer is equal to 1/2 for the model chosen and that the optimal height of the catalytic layer depends upon the coefficient for first-order reaction kinetics at the cathode, the diffusion constant for oxygen in the gas phase, and the oxygen concentration of the inlet flow.

In lay terms that is trying to say the layout of the passages for the fuel gas, such as hydrogen, and the dimensions of the passages have been identified using the math work by the group. Using the materials discussed in the paper indicates that the amount of catalyst can be reduced by a factor of 4−8, while the energy efficiency can be increased by 10−20% at high current densities.

Typical MEA Layout in a Fuel Cell. Click image for more info.

Compared to passageway layouts such as in a radiator or other ideas, and then trying to get the fuel working through a comparatively massive membrane acting as the porous transport, the lung based distribution with the activity taking place in the distribution routes offers a great increase is using catalyst resources.

Today polymer electrolyte membrane fuel cells are usually built with five active layers, all with different characteristic pore sizes. The central layer is a gas-tight ion-exchange membrane (typically Nafion) filled with water, in which protons conduct charge and where water transport takes place by electro-osmosis and diffusion. Two catalytic layers on both sides of the membrane are nanoporous with dispersed platinum, carbon, and polymer; the carbon grains (20-40 nm) form agglomerates of 200- 300 nm size, leading to pores of 20-40 nm inside the grains and 40-200 nm pores in the void space between agglomerates. These three layers comprise the membrane electrode assembly (MEA).

The MEA is covered on both sides with a porous transport layer (PTL), having micrometer-sized pores. Supplying oxygen fast enough through the PTL and the catalytic layer to the active sites can be problematic. The lack of a fast supply leads to gradients perpendicular as well as parallel to the membrane, resulting in loss in potential; clogging of pores by water can give similar losses. The Norwegians work seeks to avoid those problems.  Quote from the paper:

“To find an optimal structure starting from scratch, with all geometrical variables free, is not trivial. It is known, however, that the human lung as a gas distributor is characterized by the very same conditions (as given by eqs 9 and 10). The human lung has two flow regimes: one for convective flow and one for diffusion. The structure is such that the entropy production is constant in both parts, indicating that the entropy production is minimal for the total structure. This is exactly the situation that we want to achieve and why we take the bronchial tree as a source of inspiration…The gas supply system for the fuel cell should be compared to the first part of the bronchial tree.”

A bit of connecting the dots genius in involved here with more than a bit of objective analysis on the problems.

The paper’s authors offer, “The presented methodology is general and applies to any type of catalyst in a nanoporous catalytic layer. . . We have thus presented a method that predicts that significant catalyst savings are possible. . .  The results remain to be validated experimentally by building a cell, proving that a better energy efficiency can indeed be realized in practice for the proposed structure. It is important to establish all cell characteristics, because the loss at low potentials may not only be due to mass-transfer limitations.”

Another look at the two graphics suggests the group should get some funding for proving up the concept.  The issue is fundamentally controlling the fuel and the intersection with the catalyst.  The math looks good, the engineering quite a challenge for the test cell, and the promise quite high for getting fuel cells closer to mainstream use.

Moreover, the authors aren’t playing favorites on the fuel front either; the door is open from hydrogen on up.  The Norwegians have a great idea on the table and congratulations are in order for a very sharp innovation.  It will be very interesting to see how this idea might drive fuel cell costs down.

Chemists at Brown University have demonstrated that a nanoparticle with a palladium core and an iron-platinum shell outperforms commercially available pure-platinum catalysts and lasts longer. A writer could be tempted to repeat, bold or add emphasis.  If the Brown team’s work can be replicated and can show a commercial path they have the first treasure.  The race to the ‘Platinum Replacement Prize’ is on.

The team’s leaders Shouheng Sun, professor of chemistry at Brown and co-author of the paper and Brown graduate student and co-author Vismadeb Mazumder’s findings are now reported in the Journal of the American Chemical Society.

The precious metal platinum has two major downsides: It is very expensive, and it breaks down over time in fuel-cell reactions.

The Brown University chemists report a promising advance with the new study. The team built a unique palladium core and an iron-platinum shell nanoparticle that uses far less platinum yet performs more efficiently and lasts longer than commercially available pure-platinum catalysts at the cathode end of fuel-cell reactions.

Palladium Core Iron-Platinum Shell Fuel Cell Catalyst. Click image for more info.

The research team created a five-nanometer palladium (Pd) core and enclosed it within a shell consisting of iron and platinum (FePt). The trick, Mazumder said, was in molding a shell that would retain its shape and require the smallest amount of platinum to pull off an efficient reaction. The team created the iron-platinum shell by decomposing iron pentacarbonyl [Fe(CO)5] and reducing platinum acetylacetonate [Pt(acac)2], a technique Professor Sun first reported in a 2000 Science paper. The result is a shell that uses only 30 percent as much platinum, although the researchers say they expect they will be able to make thinner shells and use even less platinum.

Mazumder said in accrediting Sun’s earlier work, “If we don’t use iron pentacarbonyl, then the platinum doesn’t form on the (palladium) core.”

The test results, Ready?  The team demonstrated for the first time that they could consistently produce the unique core-shell structures. In the laboratory performance tests the palladium/iron-platinum nanoparticles generated 12 times more current than commercially available pure-platinum catalysts at the same catalyst weight. The output also remained consistent over 10,000 cycles, at least ten times longer than commercially available platinum models that begin to deteriorate after 1,000 cycles. That’s a “Wow!” moment.

The team created iron-platinum shells that varied in width from one to three nanometers. In lab tests, the group found the one-nanometer shells performed best.
Mazumber says, “This is a very good demonstration that catalysts with a core and a shell can be made readily in half-gram quantities in the lab, they’re active, and they last. The next step is to scale them up for commercial use, and we are confident we’ll be able to do that.”

Mazumder and Sun are studying why the palladium core increases the catalytic abilities of the iron platinum shell, although they think it has something to do with the transfer of electrons between the core and shell metals. To that end, they are trying to use a chemically more active metal than palladium as the core to confirm the transfer of electrons in the core-shell arrangement and its importance to the catalyst’s function.

The team leaders are hinting that this, a stunning of a result as it is, has room for more research and innovation.

The rest of the team and coauthors includes Miaofang Chi and Karren More at the Oak Ridge National Laboratory.  The U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy funded the research as part of its Fuel Cell Technologies Program.

The issue in a fuel cell is the chemistry known as oxygen reduction reaction takes place at the fuel cell’s cathode, creating water as its only waste.  Sun explains the cathode is also where up to 40 percent of a fuel cell’s efficiency is lost, so “this is a crucial step in making fuel cells a more competitive technology with internal combustion engines and batteries.”

For those of us with a deep-seated intuition that fuel cells are a critical segment of fuel to energy conversion power units for the future, the Brown University research team’s paper is the most important news in months.  At lower cost with useful cycles measured up to 10,000 times with 12 times the current flow – this writer is  . . . just thrilled.

Congratulations to Professor Sun, Mazumber, Chi and More.  To use an overworked word, but applies here, it’s a breakthrough.

University of Houston researcher Peter Strasser started in 2005 looking for ways to crack the platinum problem not by replacing platinum outright, as other researchers are seeking to do, but by making platinum more reactive.  Strasser and his colleagues use a process called dealloying.

First, they combine platinum with varying amounts of copper to create a copper-platinum alloy. Then they remove the copper from the surface region of the alloy. When they test the binding properties of the dealloyed platinum-copper catalyst, they found it was much more reactive than it would be otherwise.

Dealloyed Platimun Electrocatalyst. Click image for more information.

To find out why, Strasser asked Anders Nilsson, who conducts research at the Stanford Institute for Materials and Energy Sciences, a joint institute between SLAC and Stanford University and colleagues Mike Toney and Hirohito Ogasawara to put dealloyed samples under the extremely bright X-ray beam at the Stanford Synchrotron Radiation Lightsource.

By studying how X-rays scattered from the dealloyed samples, they were able to create detailed pictures (none seem to be posted on the internet) of the metal’s internal structure, revealing that the increased reactivity was caused by lattice strain – a phenomenon in which the arrangement of the platinum atoms is modified. By compressing the surface platinum atoms closer together, the process causes platinum atoms to bind a little more weakly to oxygen atoms and get closer to that magical “balance point” between fuel molecule dissociation and process materials catalytic binding.

Strasser said, “The distance between two neighboring atoms affects their electronic structure. By changing the interatomic distance, we can manipulate how strongly they form bonds.”

The choice of metal for the cathode is extremely important, as some metals cannot break apart the oxygen atoms while others try to bind too strongly to the oxygen atoms, taking them away from the key reaction. So, scientists are seeking the perfect “balance point,” where the number of oxygen bonds broken is maximized and the oxygen atoms bind more weakly to the catalyst. Platinum achieves the balance, which is strong enough to break the oxygen bonds but does not bind to the free oxygen atoms too strongly. Unfortunately, it also costs enough to make platinum-electrode fuel cells incredibly expensive.

Nilsson said, “This is a significant advance. Fuel cells were invented more than 100 years ago. They haven’t made a leap over to being a big (market) technology yet, in part because of this difficulty with platinum.”

Fuel cells hold significant promise because the cells are very efficient and the only byproduct is water.  Current fuel cell designs can require as much as 100 grams of platinum, pushing their price tags into the thousands of dollars.  Nilsson figures cutting the cost is worthwhile, “I think with a factor of ten, we’ll have a home run.”

Fuel cells and air batteries are similar. An anode provides electrons and a cathode collects them on the other end of an electrical circuit. But unlike batteries, fuel cells use hydrogen and oxygen fuel to drive their energy-producing reactions; when oxygen enters the metal cathode, it is broken down into individual atoms before it forms water with hydrogen.

The researchers next step will be to use the SSRL beam to get a closer look at the reactions between oxygen and platinum, and to determine what can be done to make the process even more efficient. The ultimate goal is to create a potential replacement not only for gasoline engines but also for the batteries found in small electronic devices.

Platinum’s big claim is the cells loaded with it are quite responsive. That could obviate some or much of the need for electron storage with batteries or capacitors.  One still wonders though, even if the team gets to 90% less or just 10% of the platinum needed now will the platinum cell be economical?  This is still not a defeat for those looking for lower cost alternatives.

Factually, the idea of using hydrogen as the reactive fuel might not be the best idea either.  But the better fuels, methane, methanol and ethanol still function much the same way and a platinum replacement is a strong hint on what paths future research might take in these fuel’s future as well.  At smaller enough platinum requirements all the potential fuels have better futures.

What would it cost to alloy and dealloy a batch?  The researchers haven’t said.  The description in the press releases doesn’t say, but as a mechanical process it wouldn’t be a huge thing – especially as the raw stock is platinum.

Good idea, good work – how much further can it go?

Oorja’s Protonics’ methanol fuel cells eliminate the dangerous and time-consuming task of switching out and recharging batteries and owning the extra sets  Oorja’s OorjaPac fuel cell sits on the forklift and feeds electrons to the battery pack, charging it as the day progresses.  Filling up the fuel cell at the beginning of a shift, ideally, provides enough power for the day.  A 3.4 gallon-storage tank of methanol powers a vehicle for 10 hours.

Oorja Methanol Fuel Cell. Click image for the largest view. See the video below for more information.

The Nissan factory in Smyrna Tennessee has tested Oorja’s product over 18 months and then ordered 60 units.  Mark Sorgi, senior manager of material handling at Nissan said the factory would save near $225,000 per year and avoid spending $300,000 for battery replacements. Oorja’s fuel cells also save time and reduce its greenhouse gas emissions.  “We can probably run anywhere from 14 to 16 hours on one tank of methanol,” Sorgi said. “It takes 60 seconds to refill versus battery change-out that takes 15 minutes.”

Methanol, a one-carbon atom chemical is one of the mostly commonly produced chemicals in the world, costs about $1 to $2 a gallon and doesn’t have to be transported under pressure so it’s easy to ship. It’s the main chemical in windshield washer fluid. Methanol can be delivered in large plastic drums and is fully biodegradable.

Oorja has improved the performance of its fuel cell. The new 1.6-kilowatt Model H is about 25 percent to 30 percent smaller than the previous version, at $16,000 costs about 50 percent less than the earlier version, and can be refilled with methanol in about a minute.

Oorja Chief Executive Sanjiv Malhotra said the initial difficulty he faced when he started the company in 2005 was to find an appropriate fuel for the fuel cell. He settled on methanol, as it was cheap and easily available. “Fuel cells are synonymous with hydrogen,” he said. “The biggest challenge I was looking to solve was the hydrogen problem.”  Methanol is an alternative fuel that is derived from various sources including wood, grass, landfills, natural gas and coal.

Obviously Oorja is working to develop a product that can be used as a range-extender in pure electric or plug-in hybrid vehicles and aggressively working to get a unit ready in 18 to 24 months.

Last month Oorja began discussing a 5 kw unit, something large enough to power a larger American style home or small business. Used as a stationary fuel cell at about 5% of the output of the Bloom unit that garnered so much hype a month ago, the cost looks to be less than 2.5% of the Bloom, getting to the range where a consumer as a large home owner or small business in the higher grid priced energy markets can make this pay off. And for some, avoid temporary peak rates, or even blackouts.

At $15,000 it’s still richly priced and the cost of battery or capacitor storage for peak usage and inverter equipment isn’t included.  But going off grid with substantial energy demand is getting very close.  Just how this might work in a utility area with buy back of over production would be a local condition calculation.

Methanol is very easy to make and can be made from wide assortment of biomass stocks.  Sized for vehicles as a range extender, it might be a very productive choice for marketing and the company’s growth.

The Bloom fuel cell made a lot of news and blog posts.  Lets hope Oorja makes a lot of fuel cells.  I’d sure rather use methanol than hydrogen and have a vehicle range extender with enough energy output to have cabin heat and air conditioning.  Have a look and listen as Malhotra is interviewed.

There are articles and blogs rich in interesting details and after an hour or so of looking through them I encourage you to just choose a few of your favorites for the hype.

Meanwhile, lets review that Data Sheet, where the due diligence would begin, before making the call for a spot on what will be a waiting list.

The Bloom Box Flowing Electrons. Please click the link to the Bloom Energy Movie page.

The BB runs on natural gas or a methane from biogas, what moist are seeing as older landfills tapped for the naturally and stimulated methane output.  The Data sheet nor any of the articles are saying just how pure the methane has to be.  The gas flows at a moderate 15 psi.  Nothing scary or alarming here.

The other fuel, oxygen is from the air.  No article or blog I’ve seen is covering if the is an air separation to pure oxygen and the Data Sheet is listing NOx at a really minor number.  If you come across that information post it to the comments for everyone.

The Data Sheet is allowing for 100kW AC with an electrical efficiency of better than 50%.  Power take off is at 480V @ 60 Hz in a 3 phase 4 wire interconnect.  Elsewhere on the site the potential is listed for taking power off DC, which is what lots of data handling installations would use in great volume.

The BB is bigger than first imagined.  At 18.6 x 7 x nearly 7 feet it’s larger than full sized pickup truck.  That doesn’t matter, but it gives a sense of scale when looking over then photos.

At just less than 3/8ths of a ton of CO2 per full rated operating hour the BB won’t be making the green crowd joyous.  Nor will the rating claim.   But these kinds of things in data sheets tend to be careful choices that any unit can make.  And we are after looking at Ver. 1.0 something.

Curiously, without much discussion the active agent is steam in the dry steam zone past 700º C.  Now, no one is looking at 15 psi methane, oxygen and dry steam in close vicinity at 700º C. Thus, the obvious safety matters haven’t been addressed.  The Data Sheet claims the units pass Underwriters Lab FC-1.  Keep in mind; there is very little experience at UL for fuel cells.

It also seems that an energy take off can be made of hydrogen requiring a water supply, a sort of have the cake and some frosting slipping over the side for later enjoyment.  The Data Sheet is using ‘municipal water’ for a source, but one has to wonder what the chemicals carried along will do to the ink coated types of anode and cathode.

The Bloom Energy Site has been filled out with an attractive array of info.  Lots of critical stuff is missing, no one is saying the BB is a mission critical unit.  It’s Ver. 1.0 something.

That’s enough – from recalling points made early in the week.  The venture capital wants to get on with the initial public offering, where the big bucks are made.  You will want to look over that data sheet very carefully.  We need to have a look at where those incentives are by state, California at 20% and the Feds kicking 30% more isn’t the same as everywhere.  That hard fast fuel cost included amortization seems elusive as well.  Don’t pretend to understand, the BB looks to be closer to the quoted 50% than 90%.

And finally, this is version one.  It will be competitively answered.  The IPO stockholders will be buying into the a race to the lowest cost kilowatt-hour.  The BB isn’t the leader yet, but hopes and crossed fingers, prayers and creative drive are making progress now.

We’ll have another look in a few weeks as more info might slip out.

A fuel cell is a device that takes molecules or atoms in on one side using a kind of ‘porous barrier’ to strip off electrons leaving the then disassociated atom or atoms on the other.  That’s as simple traditional description as I have handy today.  The issues have been the material(s) that make up the ‘barrier’ that so far have been discovered and are wildly expensive.  Breakthroughs have been coming, we saw an ‘on the market’ methanol unit out of Japan a few weeks back. Progress is getting made.  Reliability is up and costs down.

The Bloom Energy unit, as far as the reports have it so far, is a fuel cell running a bit differently.  In a high temperature containment vessel a hydrocarbon fuel such as ethanol, biodiesel, methane, or natural gas, is fed to one side of the cell.  That is explained as attracting the oxygen’s ions fed from the other side. As the ions are pulled through the solid core, the resulting electrochemical reaction ‘creates’ electricity.  One is to understand that the fuels of carbohydrates or hydrocarbons and the oxygen then combine and are emitted.  The round about math from the reports have the results at half the emissions of combustion.

This isn’t much technological know how out for an opinion. It’s surely not a classical fuel cell either.  Without the kilowatt per hour rating the value is just supposition.  Except:

Bloom Energy has persuaded 20 or so major companies to buy and install early models of the “Bloom Box” with admitted and PR hungry Google, Walmart, FedEx, and Staples pressing for the public information release.  The quotes at the CBS 60 Minutes web page have John Donahoe, eBay’s CEO, saying its five boxes (about $3.75 million) were installed nine months ago and have already saved the company more than $100,000 ($133K annually) in electricity costs, “It’s been very successful thus far. They’ve done what they said they would do.”  A bit further Donohue says, “When you average it over seven days a week, 24 hours a day, the Bloom box puts out five times as much power that we can actually use.”  With the California and Federal incentives the capital cost is reported to be about half the price – thus less than a 15-year amortization.  Fuel costs and which fuel aren’t mentioned.

Bloom’s point might be to generate buzz for a public offering.  The zing is the prediction that home units could be built for under $3,000 available in 5 to 10 years.  The flip side is the venture capital is ready to get out; public offerings are how they make the money.  This has meaning, what the meaning is will be the risk to the public offering share buyers.  But Bloom has orders and sales revenue, and more production volume should reduce prices and speed the amortization making sales more attractive to buyers.

KR Sridhar by Jonathon Sprague

Bloom CEO K.R. Sridhar is a 49-year-old scientist-turned entrepreneur who’s raised $400 million in venture capital for his Sunnyvale, California company.  Sridhar originally developed the idea for the Bloom Box after developing a device while working at NASA that would be able to create oxygen on Mars. When NASA ditched the Mars mission, Sridhar thought to reverse the oxygen-creating Mars mission box and use oxygen as the input instead, a reverse of photovoltaic solar electricity in and oxygen out to oxygen in and electricity out.  That’s being at the right place at the right time.  Those credentials got the foothold with the venture capital people.

With units built, sold, running and capital plus some cool names on the board like Colin Powell the incentive game could be quite useful for Bloom.  Already at 20% in California and a 30% Federal subsidy support, a California pitch like that can’t be real hard to make.

Can anyone contest or naysay on this?  Sure . . . The technology is reported to be simple, thermally prepared ‘sand’ as in silicon, shaved to thin squares, (sound familiar?) coat them with special “inks” on opposing sides and stack ‘em up with a low cost alloy between them.  The taller the stack the higher the output.

Might beg a few questions for tomorrow.  Add yours below.  What’s the power ratio or energy efficiency?  Using an internal combustion engine, then a turbine and now the Bloom Box, what are the ratios or percentages?  Is there a specific build for each fuel type?  Is there one build for methane, another for ethane, another for each alcohol?  Is a switch of the silicon squares all that’s needed to switch fuels?  If so, what part of a unit’s investment is standard and what part can be switched? Can fuels be mixed?

Then there are the operating questions, like the uptime percent, the fuel purity and costs and consequences of fuel contamination.  One wonders what, if any fuel conditioning might be required.

I sure hope the Bloom Box has the attributes to go to scale from small vehicles in liquid fuels to home sized power and on to grid substation fueled by gases.  One hope is Bloom Boxes make more economic sense than gas fired turbines, preferably by a wide margin.

Parallel is the Randell Mill’s Blacklight project that also could make news soon – and it doesn’t need carbon-based fuels.

News is moving fast, Brian Wang put up more background last night.

It’s looking like a great year.  Good Luck to everyone tomorrow, lets hope some smart people ask some good questions and they’re answered easily.

Toshiba Methanol Fuel Cell. Click image for more info.

At a price of about $320US the cell is still a cautious design.  And at that price its bait – Koji Kariatsumari and Hideyoshi Kume of Nikkei Electronics Asia with some consultants and help from Toshiba tore one down for their article.  Keep in mind that mass production, should it follow the latest trend seen in Blu-Ray DVD players, would take the price to under $50US.

The design seems extra safe.  There is extensive use of metal parts such as stainless steel and aluminum alloy.   Called the “Dynario” Toshiba let loose only 3000 units, in the midst of a recession, much to the surprise of engineers worldwide that are working in the field.
The Dynario seems quite mature in that comments center about the design, which stabilizes the incoming air humidity, there is no methanol smell, and it warms when running only to about the temperature of hot bath water.

The Dynario is a direct methanol fuel cell (DMFC) with a USB connector that allows it to charge mobile equipment such as cell phones and mpg players. The maximum output, together with the internal Li-ion rechargeable battery, is 2 W (5 V, 400 mA). The fuel cell is fueled with 14 mL of methanol, which, according to Toshiba, “is enough to charge a piece of mobile equipment about two times.” Kariatsumari and Kume used an LED lamp with a power consumption of 1 W to verify that it generated enough output for about 11 Wh.

Toshiba Methanol Fuel Cell Parts View. Click image for more info.

Kariatsumari and Kume say they were surprised at how many parts were inside.  The Toshiba people explain, “There are a number of custom components that just pushed the price up.”  In addition to the actual fuel cell, there was an ultra-miniature pump and valve, as well as micro-controllers, control ICs, control boards, and other circuit components. The case was so sturdy it almost seemed like overkill.  It’s built with a metal exterior including reinforcing members. Most of the people who looked inside, including mobile equipment and fuel cell engineers, agreed that it was almost certainly impossible to sell it for only 30,000 yen, considering components, manufacturing and other costs.

The Dynario has two key generating units mounted in the center of the case, one in front and another in back. The center of the case also holds a cylindrical Li-ion rechargeable battery manufactured by Sanyo Electric Co., Ltd., and two control boards mounting the power switch and input/output (I/O) pins, with the rest of the parts attached to the center case frame.

The fuel tank is located on the end of the center case frame. The case itself has aluminum alloy front and back, with plastic on top and bottom. An engineer in the fuel cell industry commented Toshiba seems to have used a lot of metal parts to maximize durability, strength and other characteristics, given that this is the first volume production model.

The generating unit positions the power cells between a stainless steel lattice and a plastic holder that acts as the fuel supply plate. The stainless lattice and plastic holder are riveted together, making it impossible to remove the generating cell without destroying the power cells. The stainless steel lattice also acts as the air inlet for the power cells, while the generating unit control board, fuel pump, fuel valve, and other components are mounted on the fuel supply plate side. The control board holds the ICs controlling the fuel pump, fuel valve, an 8-bit micro-controller, and more.

Toshiba Methanol Fuel Cell Control Board. Click image for more info.

Toshiba Methanol Fuel Cell Fuel System. Click image for more info.

The fuel valve and fuel pump can be seen mounted on the generating unit. Both components are electro mechanically driven, so key design goals must have been minimizing power consumption and ensuring durability. Additionally, use for mobile equipment imposes strong demands for small size, thinness, etc, leading one fuel cell engineer to suggest this is where manufacturers have the toughest problems.

Kariatsumari and Kume think Toshiba had a tough time designing the fuel valve, as it protrudes 6 mm beyond the other components. The fuel pump and control board have all been thinned down, but the fuel pump seems to have had insufficient development time. Thus, it has been positioned off-center and the two power cells positioned to make room for it, keeping case thickness to a minimum.

Murata Manufacturing Co., Ltd manufactured the fuel pump in the unit Kariatsumari and Kume disassembled.  It uses a piezoelectric device, and is quite thin measuring 24 mm × 33 mm × 1.325 mm. The pump discharge rate is thought to be 0.001 mL/s, with a pressure of 35 kPa.
The fuel path is from the tank to the fuel valve and into the plastic fuel supply plate.  The fuel pump then pressurizes the fuel into the fuel supply plate.

Toshiba Methanol Fuel Cell Membrane Electrode Assembly. Click image for more info.

The power cells are membrane electrode assemblies (MEA) measuring 81 mm × 52 mm, and a collector. Each MEA uses four single cells, each measuring 81 mm × 9 mm. As each cell probably has an electromotive force of about 0.3 V that means the generating unit would generate over 1 V. The step-up circuit on the generating unit control board then boosts output to about 5 V.

Kariatsumari and Kume are calculating cell output density to about 25 mW/cm2, leading a consulting fuel cell engineer to theorize it was deliberately kept low to control heating issues. Toshiba has said that it developed fluorine- and hydrocarbon-based solid polymer films, but it is unclear which was used in this product. Several of the consulting fuel cell experts commented that the Dynario is most likely the fluorine-based design.

The Dynario’s Li-ion rechargeable battery supplies electricity for the operating load until output from the generating unit stabilizes at start-up, as well as pass through powering the generating unit control circuit and other components.  The Li-ion rechargeable battery and generating unit are controlled by the 8-bit micro-controller with 2 Mbits of internal flash memory on the control board that also holds the power switch and some I/O pins.

Toshiba gave top priority to assuring safety. On the list is an auto-stop when the unit gets too hot.  Kariatsumari and Kume’s tests showed that the auto-stop function triggers when the surface temperature reaches about 45°C.  A temperature sensor at the generating unit air inlet ensures that surface temperature does not exceed a preset maximum The fuel cell is said to incorporate other functions as well, such as disabling operation at temperatures of 100°C or higher, and breaking high input currents through the I/O pins.  All in all, it’s a commercially viable design.

The obvious questions are about scaling up the output.  What we can interpret from the Kariatsumari and Kume tear down is that ‘cool’ running methanol fueled fuel cells are practical even in a seemingly high cost design.  Production in volume can greatly reduce the costs, and at over a volt per membrane electrode assembly the power output can add up with the attendant gear only needed once per unit.  Costs could plummet if sales volume grows.

Other questions are in the design that Kariatsumari and Kume didn’t report.  Just how is Toshiba keeping the humidity out?  There is something very clever in the design not discussed.  Nor did they cover the fueling process itself; is there a design to handle the methanol handily and safely by the masses? And just how efficient is it?

Even with the omissions aside, Toshiba has a breakthrough sales claim.  Fuel cells using renewable fuels such as methanol and ethanol should have a great future.  A hybrid automobile with an ethanol fuel cell would be vastly more efficient than an internal combustion engine and could offer chassis sizes and performance that American’s crave.  If you don’t like the idea of a mini sized car, fuel cell power is certainly going to be one route to salvation.

Solid Oxide Fuel Cell Diagram. Click image for more information.

But the material has three significant drawbacks: because YSZ has limited conductivity at low temperatures – SOFCs must operate at high temperatures, the use of hydrocarbon fuels creates carbon build-up, which clogs the anode, and even small amounts of sulfur in fuel contaminate the anode that dramatically reduces efficiency.  But the potential to avoid using expensive platinum is a powerful motivator.

A new ceramic material from the Georgia Institute of Technology described in the journal Science could help expand the applications for solid oxide fuel cells.  Devices that generate electricity directly without the need to separate out the hydrogen first makes a wide range of liquid or gaseous fuels potentially available for fuel cells.

Meilin Liu, a Regent’s professor in the School of Materials Science and Engineering at the Georgia Institute of Technology has his team working through the long-term durability of a new mixed ion conductor material. The new material’s development could address two of the most vexing problems facing the SOFCs: tolerance of sulfur in fuels and resistance to carbon build-up known as coking. The new material could also allow solid oxide fuel to operate at lower temperatures, potentially reducing material and fabrication costs.  SOFCs convert fuel to electricity more efficiently than other fuel cells a factor that drives the research perhaps more than the costs of the competing materials.

Meilin Liu and Team Examine Their New Material. Click image for more info.

Liu says, “The development of this material suggests that we could have a much less expensive solid oxide fuel cell, and that it could be more compact, which would increase the range of potential applications. This new material would potentially allow the fuel cells to run with dirty hydrocarbon fuels without the need to clean them and supply water.”

That would be a game changer for petroleum and alcohol fuels supplies.  Switching out efficiencies from say 25% to over 85% would have a dramatic impact on the demand as new fuel using devices enter the economy.

The typical SOFC’s anode uses a composite consisting of YSZ and the metal nickel. This anode provides excellent catalytic activity for fuel oxidation, good conductivity for collecting current generated, and compatibility with the cell’s electrolyte – which is also YSZ.

Georgia Tech’s new material development addresses all three of those anode issues. Referred to as BZCYYb as shorthand for its complex composition, (BaZr0.1Ce0.7Y0.2–xYbxO3–δ) the material tolerates hydrogen sulfide in concentrations as high as 50 parts-per-million, does not accumulate carbon – and could operate efficiently at temperatures as low as 500º Celsius or 932º Fahrenheit.  Still, that’s quite hot, but a considerable improvement.

Liu believes that two options are viable, use the material as a coating on the traditional Ni-YSZ anode or as a replacement for the YSZ in the anode.  Another possible use is as a replacement for the entire YSZ electrolyte system.

So far, the new material has provided steady performance for up to 1,000 hours of operation in a small laboratory-scale SOFC. But to be commercially viable the material will have to be proven in operation for up to five years – the expected lifespan of a commercial SOFC.
Liu says, “We don’t see any problems ahead for fabrication or other issues that might prevent scale-up. The material is produced using standard solid-state reactions and is straightforward.”

Currently the researchers don’t yet understand how their new material resists deactivation by sulfur and carbon, but theorize that it may provide enhanced catalytic activity for oxidizing sulfur and both cracking and reforming hydrocarbons.

But the news is in the temperatures, “If we could reduce operating temperatures to 500 or 600 degrees Celsius, that would allow us to use less expensive metals as interconnects.” Liu points out, “Getting the temperature down to 300 to 400 degrees could allow use of much less expensive materials in the packaging, which would dramatically reduce the cost of these systems.”

The side result is Liu and his team’s material could also be used for fuel reforming to feed other types of fuel cells.

The technology for solid oxide fuel cells is currently less developed than other types of fuel cells, Liu believes SOFCs will ultimately win out because they don’t require expensive precious metals such as platinum and their efficiency can be higher – as much as 80% plus co-generation use of the waste heat.  How close that comes to a full 100% is yet to be seen.  But 80% directly to electrons is a huge head start.

SOFCs are fascinating as they have the potential to utilize all of the energy in fuels as diverse as petroleum, through all the biofuels at a huge efficiency gain and be built without precious metals for the catalysts.  Science has gotten another step closer to a practical fuel cell oxidation device.

Fuel cells are devices that produce electricity from simple fuels from hydrogen up to the simple hydrocarbons and alcohols, without burning them, so fuel cells are a very desirable and promising technology.  Using light gases and liquid fuels could power everything from cars and homes on to small portable devices such as cellphones and laptops. But fuel cells come at a very high cost due to the materials and construction costs, thus researchers have been trying to find ways to make the devices less expensive.

One group, an MIT team led by Associate Professor of Mechanical Engineering and Materials Science and Engineering Yang Shao-Horn with researchers at the Japan Institute of Science and Technology, and the Brookhaven National Laboratory has found a form of fuel cell electrode that promises to dramatically increase the efficiency of the electrodes in the type of fuel cell that uses methanol instead of hydrogen as its fuel and is considered a top candidate as a replacement for batteries in portable electronic devices. The MIT electrodes are made of platinum, increasing their efficiency means that much less of the expensive metal is needed to produce a given amount of power.  Moreover, methanol is something that could be produced in huge quantities.

The MIT team found a key to the boost in efficiency is to change the surface texture of the platinum material. Instead of leaving it smooth, the researchers gave it tiny stairstep shapes. That adaptation approximately doubled the electrode’s ability to catalyze oxidation of the fuel and thus produce electric current. The team believes that further development of the surface structures could end up producing far greater increases, yielding more electric current for a given amount of platinum.  That is critical, as the platinum raw material is wildly expensive.

Shao-Horn says, “One of our research focuses is to develop active and stable catalysts,” and this new work is a significant step toward “figuring out how the surface atomic structure can enhance the activity of the catalyst” in direct methanol fuel cells.

Platinum In Step Construction for Fuel Cells. Click image for the largest view.

For the experiments, the team used platinum nanoparticles deposited on the surface of multi-wall carbon nanotubes. Chemical engineering graduate student Seung Woo Lee says that many people have been experimenting with the use of platinum nanoparticles for fuel cells, but the results of the particle size effect on the activity so far have been contradictory and controversial. “Some people see the activity increase, some people see a decrease” in activity as the particle size decreases. “There has been a controversy about how size affects activity.”

The new experiments show that the key factor is not the size of the particles, but the details of their surface structure.  Mechanical engineering postdoctoral researcher Shuo Chen says, “We show the details of surface steps presented on nanoparticles and relate the amount of surface steps to the activity,” By producing a surface with multiple steps on it, the team doubled the activity of the electrode.

The team members are now working on creating surfaces with even more steps to try to increase the activity further. Theoretically, they’re saying, it should be possible to enhance the activity by orders of magnitude.  That’s a very bold suggestion, an order of magnitude improvement would be stunning, going up from there would be at the edge of astonishing.

Shao-Horn suggests that the key factor is the addition of the edges of the steps, which seem to provide a site where it’s easier for atoms to form new bonds. The construction of the steps creates more of those active sites. Additionally and quite importantly, the team has shown that the step structures are stable enough to be maintained over hundreds of cycles. Stability over a long term, over tens of thousands of cycles is going to be key for developing practical and cost effective direct methanol fuel cells.

The research team also hopes to understand whether the steps enhance the oxygen reduction part of the process that takes place in a fuel cell. So far study has looked at the enhancement of oxidation. The question,  “Does the addition of steps to the surface also enhance the oxygen reduction” Shao-Horn says, “We need to find why it does, or why it doesn’t.” The team expects to have answers to that oxygen reduction matter in the next few months.

The results are reported Oct. 13 in the Journal of the American Chemical Society showing a linear relationship between the intrinsic activity and the amounts of surface steps. Increasing surface steps on Pt nanoparticles of ~2 nm led to enhanced intrinsic activity up to 200% (current normalized to Pt surface area) for electro-oxidation of methanol.

Fuel to combustion yielding heat and pressure thus converted to mechanical energy is handy, well understood and in wide use, but such an inefficient set of steps leaves a huge amount of energy unused.  Oxidation through a fuel cell jumps over several steps that need eliminated for efficiency.  The MIT, the Japan Institute of Science and Technology, and the Brookhaven National Laboratory group is showing that there are other paths with great potential.  Perhaps the structure of the catalyzing platinum will work on the other catalysts in research.

After months of quiet on the fuel cell front – this is great news.

The call for proposals opened Friday October 9, 2009 at carbontrust.co.uk/fuelcells.

The fuel cell market is stuck on production costs.  Fuel cells are already marketed around the world, with sales growing at over 60% a year – they are used to power forklift trucks, mobile phone masts or provide power in camper vans. However, they currently remain too expensive to be more widespread.  Current fuel cell system costs are still too high by a factor of at least ten for widespread uses. These costs could be brought down in the future through volume production, but projections show that even then, with today’s technology, costs would remain too high by 30-40% for most markets.

The initiative aims to deliver the critical reduction in fuel cell system costs that must be achieved to make mass-market deployment a reality. The Polymer Fuel Cells Challenge will aim to support those breakthroughs that will allow high-volume costs to come down by 35%, making fuel cell systems attractive for mass markets.  New Carbon Trust analysis shows that if substantial cuts can be achieved, the global market could be worth over $26 billion in 2020 and over $180 billion in 2050. The UK share of this market could be $1billion in 2020 rising to $19 billion in 2050.

Simply put, fuel cells efficiently convert the chemical energy contained in a fuel directly into electricity – they produce electricity like a battery but are fuelled like an engine or a boiler.  The Brits aim to accelerate the commercialization of breakthrough U.K. technology that could see the mainstream cost effective mass production of fuel cell powered cars and buses, as well as providing electricity and heat in homes and business. These kinds of mass-market applications could be saving the U.K. up to 7 million metric tons of CO2 a year in 2050, equivalent to taking two million of today’s cars off the road.

Dr Robert Trezona, Head of Research and Development at the Carbon Trust, says in launching the initiative, “Fuel cells have been ten years away from a real breakthrough for the past 20 years. This is a critical moment for U.K. fuel cell technology as emerging markets combine with technology cost breakthroughs to create a golden opportunity to launch world-beating products onto a massive global market.  Our initiative aims to drive forward the commercialization of the U.K.’s unique fuel cell expertise which will play a crucial role in the U.K.’s Clean Tech Revolution both cutting carbon and creating jobs and economic value.”

David Hart, Head of Fuel Cell and Hydrogen Research, Centre for Energy Policy and Technology at Imperial College, said: “For many years fuel cell and hydrogen technologies have been expected to become a cornerstone of a low-carbon, more efficient energy system, but the cost, durability and performance of current fuel cell systems remain unattractive in most applications. The Polymer Fuel Cells Challenge is an exciting opportunity to address these issues with a fresh perspective and coordinated approach to make polymer fuel cells an everyday commercial reality.”

Celia Greaves, at the private advocacy firm Fuel Cells UK, said: “We warmly welcome the Carbon Trust’s new Polymer Fuel Cells Challenge. The U.K. is home to a number of world-class fuel cell companies and research centers, and substantive intellectual property has already been created in this area. Initiatives such as this from the Carbon Trust are vital to strengthening the UK’s position and ensuring that the UK is innovative and remains competitive in this growing global industry.”

The Carbon Trust is focusing on polymer fuel cells for three reasons:

1.    They can be used in many different products, including all the applications with a strong prospect for carbon savings (cars, buses, combined heat and power).
2.    The horizontal structure of the polymer fuel cell supply chain allows the development of new businesses to market component technologies rather than requiring the development of completely new systems; and
3.    There is capacity and appetite from the U.K. research and industry community to deliver breakthrough polymer fuel cell technologies, which the Carbon Trust has confirmed with extensive recent engagement.

The Carbon Trust is an independent company set up in 2001 by the U.K. government in response to the threat of climate change, to accelerate the move to a low carbon economy by working with organizations to reduce carbon emissions and develop commercial low carbon technologies.

The newest fuel cells can cold start just as well as an internal combustion engine. Fourth generation General Motors fuel cells were lasting 80k miles and the 5th generation is expected to start at 120k miles and improve on from there.  That seems good, but as the economy shows now, 120k mileage is still a youthful automobile.

It’s a near sure thing the “competition” is closed to other than U.K. organizations. But that’s not the point, it’s that serious money is willing to get on with the newest and most efficient means to use fuels and transition the fuel energy into work.  Any breakthrough will be instructive worldwide.  But a head start, which is the fundamental aspect of the challenge, is what matters.  Getting cheaper fuel cells across a range of fuel candidates would be a national boon wherever it happens first.  Coming up with light carbon fuels is much easier than many thought a few years ago, and the potential from bio sourced methane and methanol up to ethane and ethanol are stunning.

It’s a ways off to say 300 thousand U.S. miles, a cost comparison with and internal combustion engine and drive sets, and sure fuel supplies with convenient availability.  But even a pure hydrogen fuel cell would be worthwhile in many circumstances.

The risk in this is in the picking.  As you’ll note, the Carbon Trust is a government creature and they’re doing what such creatures do – trying to choose a winner.  Maybe they will catch a good one, maybe not.  But the cash flow will help everyone to some extent and might evoke a privateer somewhere in the world to a breakthrough.  Let’s hope its sooner than later.