Methanol Fuel Cell

Discussion in 'Hydrogen fuel cell vehicles' started by bwilson4web, Feb 24, 2019.

  1. bwilson4web

    bwilson4web Well-Known Member Subscriber

    Source: https://www.blue.world/technology/

    • High-Temperature PEM fuel cells
    • Methanol reforming

    Methanol reforming is a relatively simple process that converts a mix of methanol and water into a hydrogen-rich gas. Before the reforming can take place the fuel needs to go from liquid to gas form by evaporation, a process that requires energy and in a generic system would mean using primary fuel, leading to lower efficiency. In the combination with HT PEM the waste heat is of sufficient temperature to drive this process, meaning an energy-free process which leads to a superior overall efficiency.

    The fundamental chemical process, which takes place in the reformer is: Ch3OH + H2O → CO2 + 3 H2

    The hydrogen (H2) produced is subsequently used in the fuel cell to produce electricity.​



    This is a sensible approach because waste heat is used to support reformulation. However, without knowing the kWh/l of methanol, it is not possible to tell if it makes economic sense. Grid power in our area is $0.10/kWh.

    Gallon of methanol, $1.10, is 3 kg. Given it is CH{3}OH:
    C(14), O(16), H(1) -> 4H / (14C + 16O + 4H) :: mass ratios
    4 / 24 = 16.7% hydrogen :: hydrogen content
    3kg * 16.7% = 0.5 kg of hydrogen in 3 kg of methanol costing $1.10
    ~$2.20/kg of hydrogen - these are industrial hydrogen rates​

    Bob Wilson​
     
    Last edited: Feb 24, 2019
  2. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    As I have said many times, fuel cell EVs can only be made practical by using a practical fuel and an onboard reformer. Well, this is exactly that: A fuel cell power system which uses a practical fuel, methanol, and a reformer integrated into the system.

    So, I'm very glad to see it! I'm very glad to see, for fuel cell cars, an alternative to using the horribly impractical, energy wasting, and difficult to handle highly compressed hydrogen. I don't see any claim at the website that anybody has yet put this system into a prototype car. I hope that will be done soon, as a technology demonstrator.

    One caveat: The methanol-burning* system will emit CO2. But since it's much more energy-efficient than a gasmobile, the emissions will be much lower, even on a well-to-wheel basis.

    In fact, since most commercially produced hydrogen fuel is made by reforming natural gas, which of course involves CO2 emissions, and since the supply chain for using compressed hydrogen involves several additional energy-wasting (and CO2-producing) steps, I think it can be reasonably argued that a methanol-powered FCEV would have less CO2 emissions, on a well-to-wheel basis, than the average hydrogen-powered FCEV.

    *Technically it's not actually burning, which is rapid oxidation. Fuel cells work by a process of slow oxidation. I'm using the word "burning" here in a more casual manner, as it's used in the phrase "burning fat" in reference to exercise.

     
    Last edited: Feb 24, 2019
  3. bwilson4web

    bwilson4web Well-Known Member Subscriber

    I failed to point out that we don’t know the energy it takes to reformulate methanol to CO{2} and H{2}. We don’t know if it generates or requires energy. My analysis was based only on the atomic mass of the elements. This remains an unknown to me and that company has not provided facts and data.

    Once I realized the hydrogen cost per kg matched wholesale hydrogen cost, further analysis could improve operational expense.

    Bob Wilson
     
    Last edited: Feb 24, 2019
  4. Pushmi-Pullyu

    Pushmi-Pullyu Well-Known Member

    It does require energy to transform the methanol into hydrogen, but I don't know what fraction of the energy contained in the methanol is used in the process.

    There is a Wikipedia article: "Methanol reformer"

     
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  5. bwilson4web

    bwilson4web Well-Known Member Subscriber

    The Wiki article does a better job than my crude atom counting since I didn't include the water and energy. My interest remains on the cost of the hydrogen recovered. The water adds two more hydrogen but we'll assume it is 'free' relative to the methanol:

    6H / (14C + 16O + 4H) ~= 17.6% :: ratio of hydrogen to methanol ... water is assumed free
    17.6% * 3 kg methanol ~= .53 kg hydrogen including the water contribution
    $2.08 / kg of hydrogen​

    The water helps but it is not an economic game changer. Meanwhile, this article has more technical details:
    https://web.anl.gov/PCS/acsfuel/preprint archive/Files/48_2_New York_10-03_0720.pdf

    Bob Wilson
     
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