--- Date: Thu, 10 Jan 2002 22:32:25 -0500 From: Steven Thomas Bond <stbondat_private> To: Declan McCullagh <declanat_private> Subject: fuel cell cars Actually this is as big a scandal from a scientific standpoint as any you handle regularly: http://www.csmonitor.com/2002/0110/p1s3-usgn.htm My reply to Christian Science Monitor: Subject: Hydrogen fueled cars Date: Thu, 10 Jan 2002 22:20:25 -0500 From: Steven Thomas Bond <stbondat_private> To: opedat_private This concept reflects the danger of decisions made by politicians unfamiliar with chemistry and and articles written by reporters who have been trained primarily in the use of language. There is a lot known about the use of hydrogen. The "hydrogen economy" has been discussed for decades. There is an article in Scientific American, now a decade or more old, about the use of hydrogen when fossil fuels runs out. There are some serious problems with hydrogen as a fuel, and only one good point - that it makes water only as a result of combustion. The really big problem with hydrogen is where to get it. It is so highly reactive there are no stores of uncombined hydrogen in nature. None! Any little wisp that gets into the atmosphere is shortly combined with the highly reactive oxygen already there. Industrial hydrogen at the present time is made from methane, natural gas. When one molecule of methane burns it forms two water molecules and one carbon dioxide molecule. Consider what happens if you intend to use methane as the source of hydrogen which is subsequently to be used as fuel. Compared to using the methane directly, energy is lost converting the methane to hydrogen and carbon, and you loose the energy obtained by oxidation of carbon. The greater efficiency of the fuel cell, compared to the internal combustion engine, offsets this loss to some degree. Since the carbon atom gives off much more energy on being converted to carbon dioxide than hydrogen does on being converted to water, liquid fuels like gasoline (C8H18) and diesel fuel (C16H34), are much more energy dense fuels than methane. So the proposition of using hydrogen for fuel boils down to where do you get the hydrogen? A vast amount of hydrogen? Fifteen years ago the answer was to use hydrolysis of water, which, of course, is very abundant. This reaction requires energy be supplied to break the hydrogen free of the oxygen. This energy is a little more than the amount of energy that is recovered when the hydrogen recombines with oxygen in a fuel cell. The "hydrogen economy" thus requires another source of energy. The hydrogen fuel (and oxygen from the air) is only an intermediary between some advanced energy source and the energy used to power the vehicle. If natural gas is to be the source of hydrogen, we are choosing a lower grade chemical source of energy, which requires a wasteful conversion, and a natural resource that is only slightly less limited in quantity than oil. A few years ago nuclear fusion (not nuclear fission, the current "nuclear power") appeared to be the shining light on the horizon. Now, for reasons I will not go into in detail in this letter, that prospect has dimmed. Nuclear power folks think interference of the wealthy and powerful fossil fuel industry with getting appropriate funding and recognition of need for fusion by government may have something to do with fusion's decline, along with the unanticipated technical difficulties and long time to payoff. Right now there are a lot of chemists and physicists who are quietly laughing up their sleeves about the adoption of a nonfeasable technology for energy sufficiency. But they are also amused by the "star wars"missile boondoggle, another technical lead balloon. And other things. God bless America! People don't realize how much we need that kind of help. S. Thomas Bond, Ph. D. 304-884-7352 ------------------------------------------------------------------------- POLITECH -- Declan McCullagh's politics and technology mailing list You may redistribute this message freely if you include this notice. Declan McCullagh's photographs are at http://www.mccullagh.org/ To subscribe to Politech: http://www.politechbot.com/info/subscribe.html This message is archived at http://www.politechbot.com/ -------------------------------------------------------------------------
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