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Device uses wind to create ammonia out of air

(spectrum.ieee.org)
147 points rbanffy | 3 comments | 16 Jan 25 14:43 UTC | HN request time: 0.699s | source
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dizzant ◴[16 Jan 25 17:21 UTC] No.42728125[source]▶
The comments here are focused on how much energy it would take to turn this into fuel. The real story here is decentralized fertilizer production, buried at the end of the article:

> this innovation could fundamentally reshape fertilizer manufacturing by providing a more sustainable, cost-effective alternative to centralized production

The high energy cost of Haber-Bosch, plus the additional cost of transportation from manufacturer to farmer could potentially be eliminated by distributed, passive fertilizer generators scattered around in the fields.

I'm no expert, but assuming sufficient local production, low concentration could potentially be overcome by continuous fertilization with irrigation throughout the growing season.

Let's find out. Some quick fiddling with a molarity calculator and an almanac:

-- 100 uM ammonia -> 1.7 mg / L ammonia

-- 82% nitrogen -> 1.4 mg / L nitrogen

-- My lawn needs around 1 lb / 1000 sq ft, or around 5 g / m2

-- So my lawn needs about 3500 L / m2 of fertilized irrigation total for the season

-- Ballpark farming irrigation is around 0.2 inches per day, or around 5L/m2

I would need to water my lawn about 700 days in the year, or more realistically up my irrigation rate by about a factor of 4, AND source all of the water from the fertilizer box.

I'm a little skeptical that I can allocate space for enough production and still have a lawn left to fertilize. The tech probably isn't ready for the big time on an industrial farm yet, but for research demo, this seems like a promising direction! Much more than concentrating it for fuel.

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darth_avocado ◴[16 Jan 25 17:33 UTC] No.42728262[source]▶
Until big fertilizer lobbies to make decentralized fertilizer illegal. Insert national security, wrong hands blah blah
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1. cogman10 ◴[16 Jan 25 17:45 UTC] No.42728401[source]▶
NGL, it would be an easy sell. You are just a hop/skip and a quack away from turning that decentralized fertilizer into a decentralized bomb making system.
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2. dizzant ◴[16 Jan 25 17:48 UTC] No.42728442[source]▶
A hop, skip, quack, jump, and fairly obvious high-energy distillation process away. The national security angle probably isn't a concern here for the same reason that this process doesn't produce good fuel.
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3. darksaints ◴[16 Jan 25 22:38 UTC] No.42731802[source]▶
Ammonium nitrate is made from ammonia and nitric acid (which is also made from ammonia). Therefore, ammonia is the only necessary direct precursor to ammonium nitrate, which is probably the most relevant oxidizer in improvised explosives today.

Not saying that it should be regulated on the basis of national security, but it’s not like there isn’t a potential security concern.