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Technology Stocks : Ballard Power -world leader zero-emission PEM fuel cells -- Ignore unavailable to you. Want to Upgrade?

To: Dr. Ezzat G. Bakhoum who wrote (2735)	6/10/1998 2:05:00 AM
From: Sid Turtlman	Read Replies (1) \| Respond to of 5827

Dr. Bakhoum: I would suggest you check with Ballard about this issue. As I understand it, a phosphoric acid fuel cell can tolerate several thousand parts per million of carbon monoxide in the hydrogen stream, while a PEM cell cannot tolerate even 100 parts. That is why the reformer for a PEM cell involves several more steps than the one used in a phos acid fuel cell, making it more expensive and energy consuming. Why do you think that the efficiency level of the PEM is so low? Trying to get the last few bits of CO out of the hydrogen stream is mostly what does it. I'm not sure about solid oxide, but I know that in a molten carbonate fuel cell, carbon monoxide is just another fuel. I don't remember all the details, but several years ago ERC tested a small fuel cell with DESTEC Energy using coal gas, or some other fuel with a huge percentage of CO, like hundreds of thousands of parts per million. The fuel cell ran like a charm for quite some time. The reasons why the car companies are taking a look at PEM rather than molten carbonate have absolutely nothing to do with this issue. I know ERC expects its molten carbonate fuel cells to go about five years between stack replacements. Assuming that the fuel cell is working 90% of the time (which would make sense--its efficiency is so high--way higher than PEM cells--it would be foolish to turn it off and get power from something else) then that works out to about 40,000 hours between maintenance calls. I am not sure how many mph a car is considered to go on average, but let us say 30 mph. So if this fc were in a car, the car would go 1,200,000 miles before major maintenance. You're telling me that this is a problem with the car companies, that they want a car to go several million miles? Get serious, doctor. PEM appears to be the first choice for cars because pressurized units can be made relatively small, because they start up quicker once given some ultra-pure hydrogen, and they don't generate any waste heat. None of these elements are a positive for stationary power, where the product doesn't have to be stuffed under a hood, it is running most of the time, and the waste heat can be harnessed to produce even more electricity or used directly in a building or factory.