Fuel cells and more nagging questions

Okay, I understand that this whole dream of a hydrogen economy run by fuel cells has a number of barriers, including storage, distribution and other infrastructure issues. Assuming these can all be overcome — and there are many people out there trying to do just that, boosted by another $119 million in funding from the Bush administration — let’s consider two other potential barriers: platinum and water.

A story in ScienceDaily raises the issue of sustainability of metal resources, and has this to say about platinum: “Researchers believe scarce metals, such as platinum, face depletion risks this century because of the lack of suitable substitutes in such devices as catalytic converters and hydrogen fuel cells.”

I understand a lot of work is being done to try to reduce platinum dependency in fuel cells, or to replace platinum altogether. Unless these goals are achieved, it seems that fuel cells the way they are today will simply be driving into a brick wall.

Then there’s water. If water is to be used in the future as a source of hydrogen through electrolysis, and if — correct me if I’m wrong — you need to use relatively pure water to accomplish this, then tell me where this water is going to come from when we have water shortages/crises in many parts of the world — including the United States? This may be oversimplifying things, but water is essentially being positioned as a fuel for the future at a time when we are running out of it for basic things, such as survival (and of course for keeping Arizona golf courses green).

Then again, once you run hydrogen through a fuel cell and it combines with oxygen you get the water back… so perhaps I should just shut up.

4 thoughts on “Fuel cells and more nagging questions”

  1. You’re right about water being an incredible fuel source. One use of that rescource is to recapture the heat of hot water going down the drain. What a waste! There is off the shelf technology (www.gfxtechnology.com) that can capture up to 80% of the heat that would otherwise go down the drain. This is not smoke and mirrors. Should be part of all building codes.

    Richard Garbary

  2. I’ll share what I can here, though I wish I had more information for you.

    This summer I attended the CNE and I distinctly remember talking to one of the company reps in the Hydrogen Villiage about their fuel cell model. They were pitching the fact that theirs was better than Hydrogenics because their version didn’t use platinum. I believe it used an alkaline-based model, but that’s about all I remember (unfortunately)

    Secondly, regarding using water as a fuel source, it should be mentioned that pure water (that is, H2o only) will I’ll share what I can here, though I wish I had more information for you.

    This summer I attended the CNE and I distinctly remember talking to one of the company reps in the Hydrogen Villiage about their fuel cell model. They were pitching the fact that theirs was better than Hydrogenics because their version didn’t use platinum. I believe it used an alkaline-based model, but that’s about all I remember (unfortunately)

    Secondly, regarding using water as a fuel source, it should be mentioned that pure water (that is, H2o only) will not conduct electricity. Water needs ions in in the mix to actually conduct the current as far as I know so pure water may not be an issue.

    Unfortunately though, I’m not sure about this either 😉 Wish I could be of more help.

  3. As far as I know all PEM fuel cells such as those made by Hyrogenics use noble metal electrodes. Some are experimenting with nanocarbon materials with a little sucess. Mixing a little platinum with the graphite shows some promise and uses much less metal than current models.

    Fuel cells that operate at an eleveated temperature such as zinc oxide fuel cells (SOFC) and molten carbonate fuel cells do not need noble metal electrodes. Molten carbonate cells are commercially available but are combersome and toxic and are not suitable for vehicles or small applications. They are being used for large, 250 kW to 2.5 MW applications, usually CHP applications where waste heat can be recovered and an overall efficiency of 75-85% can be obtained.

    SOFCs are not toxic and are much more compact. Some are developing them for cars, where most of the heat would be wasted. ZETEC, Woburn, MA, seems most advanced of the several SOFC companies.

    See The Energy Blog under the category of fuel cells for more details.

  4. PEM fuelcells are enormously over-hyped, which is unfortunate because they’re a great LONG TERM part of the renewable energy mix.

    The low-hanging fruit for conversion to renewable energy SOURCES are the stationary energy users, particularly electricity generation and heating. Until nearly 100% of the stationary users are converted to renewable energy sources, there is no point in even attempting to use hydrogen as a transportation “fuel”. Biodiesel from waste bio-oils, yes! Cellulose-derived ethanol, probably yes too, once Iogen actually has a truly viable process. But hydrogen? It’s a mistake to even consider it.

    If the original energy source used to produce the hydrogen is a fossil-derived hydrocarbon, making hydrogen from it to use as a transportation fuel makes ZERO sense from an energy efficiency/greenhouse gas emissions standpoint and virtually zero sense from a smog/toxic pollutant minimization standpoint. The conversion efficiencies from fuel to hydrogen, combined with the costs and efficiency reductions resulting from hydrogen fuel storage, more than cancel out any efficiency benefit offered by the fuelcell. The enormous costs of using and distributing hydrogen and of building fuelcell vehicles would therefore be a wasted effort. These are all mature technologies, and though incremental gains are possible there is no massive breakthrough which will make these problems go away.

    Furthermore, unlike electrolysis-produced hydrogen, all fossil-fuel derived hydrogen contains some quantity of carbon monoxide which is a poison to the platinum in the PEM fuelcells. Efforts to remove this CO reduce the hydrogen production energy efficiency even further, as well as putting a hard limit on both the efficiency of the fuelcell itself AND the minimum quantity of platinum needed to make the cell in the first place.

    When you consider that a good platinum ore may be 1 part per million platinum, the enormous environmental cost of platinum production must be taken into consideration as well. This consideration alone rules out the conversion of all existing IC engine vehicles to fuelcells, ever!. Platinum too is a non-renewable resource, and current recycling rates for platinum are abyssmal despite its enormous cost.

    Let’s be real: there is no single technological fix to our addiction to the personal automobile. It is not sustainable on any level for each of us to drag several tonnes of metal around with us everywhere we go!

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