Longshot City

So dig.  There are some very important chemicals — some of them viable piston engine fuels as well — that are conventionally made out of oil & gas that can instead be made with air, water and renewable electricity.  At a certain price-point for the electricity, their “synthetic” renewable versions become price-competitive with the conventional fossil stuff.

For instance, ammonia (NH3) is a big-money industrial chemical.  It’s used to make artificial fertilizer, for one, and is also a viable piston engine fuel that’s storeable at room temperature under propane tank pressures.

The N in ammonia is distilled from the air, and the H is typically extracted from natural gas.  However, both of these elements can be obtained from air and water with cheap-enough electricity.

At a rough wholesale price of $200/ton, and a heating value of 18.6 mega-joules/kg, that means that the heating value of ammonia is going for 4 cents per kilowatt-hour.

Ergo, simplistically speaking, if someone could generate renewable electricity for 2 cents/kw-hr and use it to drive a 50%-efficient process for making ammonia from air and water, then the resulting product would be price-competitive with the stuff made from (air and) natural gas.  This assumes that the factory is free, which of course isn’t true, but I’ve read over and over that when it comes to making ammonia, the dominant cost is the gas feedstock, not the capital payments on the factory itself.

So.  2 cents/kw-hr could lead to a monster industry that displaces demand for natural gas and liquid motor fuel.  These are some mighty-big revenue streams we’re tampering with here.

Furthermore, let’s talk about methanol (CH3OH), an even-better motor fuel because it stores at room temperature and atmospheric pressure.  Methanol can theoretically be made from hydrogen and CO2, but no one’s yet had reason to do this on an industrial scale.

Well then, hydrogen can be obtained by electrolyzing water, and CO2 can be extracted from the atmosphere (or captured from the exhaust of a gas or coal power plant).  I posted a little earlier about a new process that allegedly extracts CO2 from the air at an energy cost of 1000 kw-hr/ton.

Ergo, one can imagine a process that sucks in water and air, extracts the hydrogen and CO2 from them respectively, reacts them somehow via the “reverse water gas shift reaction,” and spits out methanol.  From what I’ve been able to calculate, if the 1000 kw-hr per ton of air-extracted CO2 figure is for real, and if the rest of the process were 100% efficient, then the electricity feeding this process would have to cost 3 cents/kw-hr in order for the resulting methanol to be price-competitive with diesel fuel (the heating value of which goes for 4 cents/kw-hr as well, just like ammonia, which is interesting).

So.  The Point I’m trying to make here is that agriculture (via ammonia) and piston engines (via ammonia or methanol) can be economically driven by renewable electricity if that electricity is cheap enough.  No batteries, no fuel cells.  If these processes can be made 50% efficient, then “renewable ammonia” could be made at 2 cents/kw-hr, and “renewable methanol” at 1.5 cents/kw-hr.   (Roughly, and assuming the factories are free.)

Those are low numbers, but at least not comically low.  If anyone can actually crack them in a scalable way then it looks like they’d be creating a multi-trillion-dollar industry.  Not only would it displace where we get our electricity from (that happens at a much higher price point, around 5 cents/kw-hr), but our fertilizer and motor fuel as well!

That’s a big damned business!  Way bigger than Google.

BTW, for your reference, 1 cent/kw-hr = 8.7 cents/watt-year, or ~50 cents/watt over five years or ~$1/watt over ten years.  That gives a rough idea of what the installed wattage will have to cost in order to make such low electricity prices possible.

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UPDATE: We’ve all heard about how gasoline cars can be converted to run on methanol, so that’s an obviously-done thing.  But what about ammonia?  Aha!  As further proof that ammonia is a perfectly-workable motor fuel as well, watch this video about a man who converted his ’81 Impala to run on it and is still driving it that way!

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UPDATE #2 (Nov 17 2008): Thanks to some very good contributions from you kind and handsome commenters, I’ve learned about a still-experimental but very promising processed called SSAS, or “Solid State Ammonia Synthesis.”  It’s basically an ammonia-powered fuel cell driven in reverse.  Nitrogen + water + electricity in –> Ammonia and Oxygen out.

This is a big deal for many reasons:

R1: It uses about 40% less electricity than an electrically-driven Haber-Bosch process (look up Haber-Bosch in Wikipedia).  Quoted/estimated numbers are about 60% efficient when compared to the (unattainable) ideal, which is great because I was hand-waving/hoping for 50% efficient above.  This savings mostly has to do with the fact that SSAS doesn’t make hydrogen gas as an intermediate step.  That’s good, because otherwise, in Haber-Bosch, the reaction of Hydrogen and Nitrogen to make Ammonia is a exothermic one, thus blowing some of the energy it took to make that pure Hydrogen gas in the first place.

From what some experts have estimated, 2 cent/kilowatt-hour electricity feeding SSAS would produce ammonia at about $220/ton = $1.75/equivalent gallon as a motor fuel, which would rock the house!

R2: It has the potential to cut way down on the up-front cost of an electricty-to-ammonia factory because it all happens at solid state and low pressure.  There’s much less pumping, expanding, piping, boiling, condensing, separating and heat-exchanging going on.  The reaction chamber of a Haber-Bosch reactor works at 200-300 atmospheres (3000-4500 psi), which doesn’t come cheap!

R3: It flattens most economies of scale.  A SSAS ammonia factory of output “10 units” costs basically 10 times that of a factory of output “1 unit.”  It’s basically linear.  The efficiency is pretty much constant across scale as well.  This means that small electricity-sinking ammonia-making factories would be as economic as big ones.  (SSAS plants of most sizes would surely be made of parallel-running shipping-container-sized units of capacity, which is exciting for the mass-production benefits of affordability and scalability.)

R4: They can work intermittently.  A Haber-Bosch reactor is apparently a necessarily always-on kind of thing, like an iron smelter in a steel mill.  Turning a Haber-Bosch reactor (safety) on and off is a days-long production.  SSAS, on the other hand, can be throttled in a second.  This is perfect for sinking variable and intermittent power, like from a wind farm or the otherwise-unused nighttime baseload output from a dam or other power source that feeds a varying load but is barely throttleable itself.

So how about that!  What’s neat about this is that it points to the business model of setting up windmills in remote un-grid-connectable but hella-windy places (like Patagonia, Alaska, Tierra Del Fuego, etc.) and using that resultingly cheap but variable electricity to make ammonia.  A truck or ship lumbers up occasionally to empty the stationary tank and haul it away to market.  Once SSAS is fully real the above is a solid play.

(Also, it looks good for sinking cheap electricity generated far out to sea, which I’ll get to later 😉 )

This entry was posted on November 11, 2008 at 7:38 pm and is filed under inventions/schemes.