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Gold/Mining/Energy : Global Thermoelectric - SOFC Fuel cells (GLE:TSE) -- Ignore unavailable to you. Want to Upgrade?


To: Vitalsigns who wrote (4137)11/19/1999 12:09:00 PM
From: blue_chip  Read Replies (2) | Respond to of 6016
 
SOFC's, PEM's and Today.

Many of you may have done some research and read into articles relative to power generation and SOFC's as well as PEM's. Before I go any further though I would like to say one thing. This isn't to me about GLE vs. Ballard or GLE vs. PlugPower, etc. It to me is not a matter of wanting to see one Company succeed and another to fail. We all want our respective companies to be successful. It is inevitable however that the 2 technologies are compared. The comparison however is based on the timing. Both SOFC'c and PEM's have advantages and disadvanteges. These change when you take the two technologies and examine them on a timeline. A timeline showing the status of the worlds energy infrastructure, the technology available at that time, the cost of the technology, and the world demand for energy. As you travel from say today to the year 2100 the worlds demand for energy needs to be satisfied and uninterrupted. Each technology has its place on the timeline which give it somewhat of an edge over the other. Both the SOFC and the PEM have their place. My feeling is that the SOFC is the fuel cell that works with what exists today. The PEM is the fuel cell that works with what we may have in the future.

What the world has today:

1. An existing energy infrastructure based on mainly power and energy production from hydrocarbon fuels (gasoline, diesel, natural gas, etc.), hydroelectric generation, nuclear power, solar power, wind power, and coal. (these are not placed in order of greatest use to least use)

2. An increasing need for more power daily. This need is one which cannot be interrupted. Radical changes to the way we satisfy this need will create chaos. There are alot of ways to satisfy this need however if we choose the radical we will end up with chaos. There are alot of articles out there on estimates on how much world power demand will increase in the comming years.

3. An increasing need for cleaner energy to offset the impact we are having on our environment.

4. We live in a world based on assumptions. People assume when you turn the handle on your tap in the kitchen that water will come out. Most people (right or wrong) pay little attention to the amount of energy they use. We all "say" we should be more energy efficient but how many really are?

5. The is a current "energy economy" in the world. Millions and billions of dollars are invested in the current infrastructure. There are also aot of people who rely on this industry for their work. Alot of these Companies have alot of influence and weight. You cant just say ok, as of January 1, 2000 fossil fuel consumption will be banned world wide. Look at the tabacco industry for example, smoking is bad for you however have they banned cigarettes? No. Do they cause cancer? Yes. Well then, why haven't they banned them? Well, its because ther is a whole enconomy within ours that is based on tobacco. On top of that, there are millions of people around the world who are addicted to tabacco. They can gradually change smoking laws to restrict areas and make it increasingly more difficult to smoke however you would never see an outright ban on tobacco products. The only way you eliminate this is by changing the consumer, and people don't change, or at least not easily. The world is full of people who talk the talk, but do not walk the walk.

6. Money, nobody wants to pay extra for a solution. They do all these survey and such a great percentage of people say the recognize the need for change and say that they do conserve, but how many actually do? All these people in these surveys who say they would be willing to pay so much more for cleaner more efficient means of energy. My guess, is that most answer for their neigbour. They say yes they are willing to pay more, but turn around and put the oweness on their neighbour to make the change. If you want an example just look at GM's EV1 vehicle. If you have read alot of the pre-EV1 talk and looked at GM's estimates of how many vehicles they figured they could sell and compare them with the actual numbers they have sold to date the program looks like a complete and utter flop. Again, the public said it would switch but hasn't.

7. Because we are so slow as people to change, the longer we go before we do means the amount of change required to compensate or catch up will grow, yet at the same time we will remain resistent. I think we all want a change, but a change that is less noticable, a change that we can implement that we can afford, and a change that does the smallest change possible in the way we live our lives, that does not inhibit our mobility, our consumption, and the amount of money in our back pockets.

There are several different technologies that address this change. The following is why I think the SOFC will be embraced more rapidly today than the PEM. This is not a question of who gets the most news, it is a question of what works, practically, economically, and societally.

PEM fuel cells are advantageous because of their ability to produce power almost on demand. A PEM fuel cell operates at temperatures ranging around 90 degrees celcius. Beacause of this low operating temperature exists the time required and the point which the cell can produce full power is considerably faster than a SOFC from "cold" temperature. This is the biggest factor which has given the PEM its boost to the forefront. This helps address our "I want it now need", it address the "hop in and go" attitude. For transportation especially it is an ideal solution in mind. I could see how back when companies started working on fuel cells how they would choose the PEM. They choose the ideal solution that would satisfy the way we live as people and decided that they would engineer backwards through its problems. They choose what they saw as the best at the time and are trying to make it work. They did not choose an answer to the problem that works in the "real" world today. that fits in the "real" world today and engineer forward. For this reason you have (had) seen all the talk about PEM's.

Problems with the PEM to be resolved are:
1. Fuel Delivery System - What type of fuel works to produce the "pure" hydrogen this cell needs to operate. What type of fuel source will it use? On board or reformed hydrogen?
On board hydrogen is the cleanest, most efficient, and works the best, however the world today does not have a hydrogen infrastructure, nor can I see one anytime soon. Hydrogen itself has its definite limitations. Because hydrogen has a very low density it has to be cooled and stored under great pressure. The volume of hydrogen needed to make a vehicle go to similar ranges that we drive today for instance is significantly large. Beacause of the low density it needs to be super cooled, it also needs to be highly presurized. When you fill up a cylinder with hydrogen you have to make allowances for what happens when the gas warms up. Its like this, hydrogen is super cooled to increase its density, that allows for larger amounts of hydrogen to be stored. Once that hydrogen starts to warm in its cylinder it expands. There is only a certain amount of expansion that can happen until the pressure is too high and some of the gas needs to be vented. It does not take long for a full tank of hydrogen to be an empty tank of hydrogen. They are working with other storage technologies which may help increase the density of hydrogen that can be stored without expansion problems, it is through the use of what the industry is calling nano tubes. These in my mind expensive and a long time away from being a real solution. One other thing that comes to mind is things like parking garages etc. They do not allow propane vehicles to park in a parking garage, they wont be letting tanked hydrogen vehicles park in one a bleed their hydrogen into a confined space.

I'll continue on the next post........



To: Vitalsigns who wrote (4137)11/19/1999 12:15:00 PM
From: CH4  Read Replies (1) | Respond to of 6016
 
No problem try this link... you'll need Acrobat Reader... move icon to document type next to Nov. 17 1999 sedar.com



To: Vitalsigns who wrote (4137)11/19/1999 1:11:00 PM
From: blue_chip  Read Replies (1) | Respond to of 6016
 
PEM's SOFC's cont.....

The alternate to tanked/ stored hydrogen onboard would be hydrogen reformed onboard from a fuel reformer/processor. This would allow the PEM powered vehicle to operate in extended ranges and be a solution to the hydrogen storage problems. This however, adds additional complications. The reforming process of extracting hydrogen from hydrocarbon fuels changes some of the intial advantages of the PEM. The reformer to make this hydrogen (a seperate piece of equipment from the cell) runs at a substantilly higher temperature than the PEM fuel cell. This means, similar to the SOFC, although the PEM cell itself does not require the time to start up, the reformer will. Suddenly the face of the playing field changes. We have two technologies that will operate or better said begin to operate in the same proximity of time. In addition to this, the PEM in combination with the reformer faces additional difficulties. You've come up with one answer to storage but you've created a pandora's box of others. The fuel reforming for a PEM is complex and expensive. Expensive not only because the reformer needs to gasify the fuel, it also needs to seperate the fuel streams, i.e. pull the hydrogen gas out of the other gasses that will be present when the fuel is gassified. Sulphur would have to be extracted if present, CO, etc. Not only that, but the reformer itself utilizes energy to operate.

Other problems.
1. Climate - PEM fuel cells are limited in the areas of the world they can be used. The cells cannot freeze as there is moisture present in the membrane. This moisture would expand and ruin the cell if it were to. A PEM always has to be kept above freezing level. Either through constant operation, or by adding supplementary heat to the cell when it is not in operation yet reamins exposed. GM seems to be working hard on one soolution as is Ballard im sure. I think GM is adding some sort of antifreeze to its fuel stream. When not in operation and in the cold the there would be antifreeze in the membrane which would inhibit expansion damaged to the membrane cause by freezing. GM claims to have solved this down to temperatures of -20 degrees so far, others, have not yet announced any advancements. Take Ballards busses in Vancouver for instance, they are not allowed to be parked inside the bus barn because of the hydrogen. They take hoses hooked up to heaters and put them in the cell compartment to provide constant protection.

Sulphur. PEMS have little to no tolerance at all to sulphur. Sulphur in a fuel stream at very low levels will contaminate the cell.

CO (Carbon monoxide) PEM's as well have little tolerance to Carbon monoxide, again, it poisons the cell membrane and kills it.

Companies developing SOFC's have taken a different approach to the fuel cell problem. Instead of choosing the "ideal" solution that satisfies the need for "immediate" immediate power, they have chosen a solution that works in the world today. A solution that works with todays infrastructure, its fuel system, and have turned around and looked for ways to make this technology suitable for mobility and methods to make it suitable for use in an "on demand world".

Disadvantages of a SOFC
1. Start up time - as a SOFC works at a higher temperature than a PEM the amount of time required to get the cell to a temperature required to facilitate the production of electricity is greater.
2. Sealing of the cell. When used for applications that require frequent start-ups SOFC's have a problem with expansion and contraction. Warming a cell slowly and cooling it down slowly is one way to elleviate sealing problems, but when you rapidly heat or rapidly cool the cell the coefficient of expansion and contraction between the cell materials and its supporting structure etc differs. The difference between the two coefficients cause breaks in the seals of the cell. If you have a fundamental understanding of how a cell works its like this. The anode compartment and the cathode compartment are two different chambers, now when hydrogen enters the differing atoms take alternate routes to get to the other compartment. One atom can actually penetrate the cell membrane the other cannot. Think of it as sifting gravel through a screen. The smaller particles that fit through the sreen can get past, the larger particles however cannot and take an alternate route to the otherside. It is this splitting of routes that causes an electric current. Now if the cell has cell sealing problems and it faces rapid start up and shut down the differeing coefficients of expansion between the material cause this seal to crack. Take a dish of mud and allow one to dry slowly and take the other one and dry it rapidly and you will see the difference. Now because the cell seperates these two comparments any failure in the membrane will cause an effect like getting a hole in that screen and both different atoms taking the same path to the otherside of the cell. It is by isolating the poitive and the negative ions and making them take seperate patsh to get to the otherside of the cell that current is made. If there is a hole that both ions can get through then you no longer have seperate paths and no longer have current.