So, this fuel from air story

I don\’t know enough chemistry to know whether this makes sense. Even if The Telegraph has or has not garbled it:

A small company in the north of England has developed the “air capture” technology to create synthetic petrol using only air and electricity.

Experts tonight hailed the astonishing breakthrough as a potential “game-changer” in the battle against climate change and a saviour for the world’s energy crisis.

The technology, presented to a London engineering conference this week, removes carbon dioxide from the atmosphere.

The “petrol from air” technology involves taking sodium hydroxide and mixing it with carbon dioxide before \”electrolysing\” the sodium carbonate that it produces to form pure carbon dioxide.

Hydrogen is then produced by electrolysing water vapour captured with a dehumidifier.

The company, Air Fuel Syndication, then uses the carbon dioxide and hydrogen to produce methanol which in turn is passed through a gasoline fuel reactor, creating petrol.

Methanol to petrol I can accept as being obviously possible. No idea at all about the previous step, the sodium hydroxide to sodium carbonate.

And electrolysing H2 out of water is going to be an expensive process even if we know that it can be done.

Further, the use of sodium hydroxide will be interesting. As that is produced by the chloralkali process. Which in itself is hugely energy intensive (it\’s essentially the electrolysis of sodium chloride, or common salt).

I\’m willing to believe that the chemistry could work. I\’m absolutely certain that it\’s a damnably inefficient method of producing storable and transportable energy. And I\’d be absolutely amazed if anyone ever managed to make it economic.

Anyone see any other faults with it?

Update: OK, finally I see why it\’s rubbish. I should have remembered that I know some people who make sodium hydroxide. And they tell me that they\’ve got free (as in, please take some, it\’s free) hydrogen as a result of the process. So we\’ve already got the H2 earlier in the process and there\’s no need at all to electrolise it from water. Meaning that they must be mad or having a larf.

26 thoughts on “So, this fuel from air story”

  1. Funny to see this story in the papers today, as I am off to see a Molten Carbonate Fuel Cell (MCFC) in situ today…the point being that the chemistry is near enough exactly the reverse.

    MCFC’s are very efficient forms of producing electricity, and get their inputs from burning methane. Question really is about how efficient turning the process on it’s head.

  2. It’s all scientifically plausible (the company describes its process here). Producing hydrogen by electrolysing water is straightforward, but I believe commercial production of hydrogen gets it (and carbon dioxide) from methane (and water), which is running part of the process in the opposite direction.

    This is all going to be hugely energy inefficient, compared with electric cars say.

  3. Agree about the inefficiency and given the current availability of Oil & Gas (especially through fracking), though “Sure, you probably can, but why would you want to”?

    Easier to setup a solar power plant and electrolyze hydrogen. That at least can be done more cleanly.

    In short, interesting technical demonstration, but given current price and easy availability of oil I can’t see this taking off in a big way.

  4. “No idea at all about … the sodium hydroxide to sodium carbonate”: Christ, your father really should have sent you to Ampleforth!

  5. Anyone see any other faults with it?

    Yes, a big one. The extra oxygen this will give to the perpetual motion/Brown’s gas/oxyhydrogen boosters/fuel pill/etc nutters. I predict this story will appear on a thousand fraudulent and/or deluded requests for funding that end up “suppresed [sic] by Big Oil” by the end of the year.

  6. @ dearieme I think I can see why Tim doesn’t understand because the spoof says that:
    You add CO2 to NaOH to get (Na)2Co3 so that you can electrolyse the (Na)2CO3 to get CO2!!

  7. 1) The use of lye to suck CO2 out of the air is what they used to (still?) do on submarines.
    2) The resulting carbonate provides a concentrated source of CO2 (the two step process is to achieve near-pure CO2). Whether that’s got any better efficiency than a cryogenic approach to freeze it out, I can’t say.

  8. I think the point of all these technologies is storage. Storing electricity is much more complex and planes for example really need high density energy storage (which batteries are not). It’s just a variation on the methanol economy concept. I have read that they are reaching 40% efficiency with a similar technology and aiming at above 50%. Which is not great compared with 85% from a battery, but it could still be a piece of the puzzle…

  9. 5 litres in 3 months. Don’t call us, we’ll call you.
    Nothing new about the (electro)chemistry involved. All they need is a power station at the front end.

  10. It’s a long time since I taught chemistry but a cursory look indicates that the chemical processes add up. The big problem is that most of the reactions require energy and only a fraction of the total energy input will be stored in the resulting fuel. Maybe as low as 15-20%. By any standards that’s not very efficient and is likely to go even lower if the energy source is intermittent wind, solar or wave energy which would work the process on a stop / start basis.

  11. It’s not Green insofar as depriving green things of huge amounts of CO2 will turn them brown.

    Remembering my A level chemistry (or alchemy as we called it in those days) just looking at the chemical symbols for the source and the chemical symbols for the product make me believe that putting the “petrol” together is more expensive than taking it apart i.e., burning it.

  12. Burn naturally occurring fossil fuel to generate electricity to manufacture a smaller quantity of artificial fossil fuel, in order to avoid using natural fossil fuel in motor vehicles.

    Got that.

    Next time: Gold From Lead, followed by How to Achieve Perpetual Motion.

  13. Correct me if I’m wrong but, if a significant part of the energy input is coming from solar PV this is just a hellishly complicated & inefficient way of producing biofuels simply to remove the prefix bio.

  14. “using only air and electricity”……

    4 lines later

    “involves taking sodium hydroxide and mixing it with carbon dioxide”

  15. What baffled me was why anyone would want to extract the CO2 from air?

    Surely this sort of plant would sit next to a conventional power station and use the CO2/water from burning gas.

    If these stations were the ‘spinning reserve’ then the electricity they were generating on the rare occasions when wind farms were producing leccy could be used for to make methanol to be burned in plant to generate more electricity.

    Still, I’m not convinced it would be efficient enough to make much sense even if we just used it as a glorified battery….

  16. So Much for Subtlety

    Has no one pointed out these idiots have managed to recreate something people have been doing for years, perhaps even centuries?

    They are using a complex procedure to remove and purify CO2 from the air and then combining it with hydrogen to produce methane or methanol. Great. If you have a large supply of cheap hydrogen lying around. Most people don’t.

    But I can do this on a bigger scale using simpler technology. A pine tree for instance. Then you cut it to get the sap. You then distill it. Hey presto, turpentine.

    You can use it in car engines – Honda’s first motorbikes ran on turps. You can do pretty much everything you might want to do with methanol with it. Even drink it (heavily diluted with gin) although I would not recommend it.

    Simple technology. Using solar power. But somehow I don’t think I would get a great fanfare of press releases if I said that is what I was going to do.

  17. So Much for Subtlety

    diogenes – “what about harvesting the energy in cucumbers?”

    You probably could, but would you want to? With cucumbers, I would probably ferment them the old fashioned way to produce alcohol. I suppose a plus is that no yoof would want to drink it.

    But we have any number of ways of doing this. You could dry them and then burn them without much free oxygen. Producing cucumber charcoal. Which you can then burn with limited oxygen and some water, to produce a feeder gas. In WW2 people used to run cars on this although it can’t have been good for them.

    If you really wanted you could take the cucumber charcoal and produce a whole range of synthetic fuels via the Fischer-Tropsch process someone mentioned. But why would you want to? I mean, really?

    The sensible thing to do with cucumbers is feed them to cows and produce methane from the resulting cow (and human) sh!t. Because then at least you get some milk and hamburger meat.

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