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Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

nature.com

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Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#141

Post by pfdietz »

wolfi1 wrote: post #105
zeristor wrote: post #27

Looking at the paper, in similar papers reference is made to this paper published 13th September 2023: “Laser-induced nitrogen fixation” https://www.nature.com/articles/s41467-023-41441-0 This is Open Access, and mentions how that is also a leap forward in Nitrogen fixation “Abstract: For decarbonization of ammonia production in industry, alternative methods by exploiting renewable energy sources have recently been e…

"The corresponding lowest energy consumption of ammonia synthesis based on the light power can be calculated to be approximately 322 kWh kg−1 NH3 (Fig. 3b). This value is significantly higher than that (10 to 13 kWh kg−1 NH3) of the H–B process at an industrial scale" still way to go. found nothing about the "subsequent hydrolysis" step, skimming the article

Yeah, that's grossly too inefficient. This is nothing more than a lab curiosity.

Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#142

Post by pfdietz »

cornholio wrote: post #129
RetroTechie wrote: post #7

Earlier quoted context omitted.

Not just fertilizer: "In addition to its use in the fertilizer and chemical industries, ammonia is currently seen as a potential replacement for carbon-based fuels and as a carrier for worldwide transportation of renewable energy." Long-term grid storage? Publication: 22 July 2022 Anyone know if maybe some pilot / small scale production facility has been set up in the mean time? I've read about a farm that produced i…

The Haber Bosch reaction does not produce any CO2: N2 + 3H2 -> 2NH3 The challenge is getting the zero emission Hydrogen. The process presented here is somewhat better than using electricity for the electrolysis split water, but still substantially more expensive than the gray Hydrogen obtain by cracking Methane gas and releasing the CO2.

Where did you conclude it was somewhat better than using electricity for electrolysis?

Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#143

Post by pfdietz »

fbdab103 wrote: post #8
RetroTechie wrote: post #7

Earlier quoted context omitted.

Not just fertilizer: "In addition to its use in the fertilizer and chemical industries, ammonia is currently seen as a potential replacement for carbon-based fuels and as a carrier for worldwide transportation of renewable energy." Long-term grid storage? Publication: 22 July 2022 Anyone know if maybe some pilot / small scale production facility has been set up in the mean time? I've read about a farm that produced i…

Are there power plants today that burn ammonia directly? If not, is it a simple/cheap enough conversion?

I think many (most?) combined cycle plants use ammonia to destroy NOx in the exhaust (selective catalytic reduction). Some diesel cars use this technology as well (using urea instead of ammonia).

Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#144

Post by mcpackieh »

sidewndr46 wrote: post #133
anon_cow1111 wrote: post #91

Earlier quoted context omitted.

Yes, the difference is tannerite (by yield) is many times more expensive, and much easier to trace when someone buys hundreds of pounds of it from a sporting goods store. Similarly, a random individual buying a half ton of AN would probably trip some kind of alarm bells somewhere.

half ton? If I was headed to a friend's house who owns a farm and they asked me to pick up half a ton of farm supplies I would think nothing of it. Even my truck with its tiny payload can carry that around

If somebody asks you to buy half a ton of fertilizer on their behalf, I suggest you think twice about it. Why do they want you to buy it for them? Even if he's a farmer, with a rational use for that much fertilizer, why is he making such an unusual arrangement to receive fertilizer through his friend instead of buying it himself normally?

Who knows man, maybe feds caught him with some pot plants and now he's setting you up in some sort of bullshit anti-terror sting to cut a deal. Regardless of what kind of truck you have, casually buying half a ton of fertilizer for somebody else is an odd request that warrants some explaining.

Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#145

Post by danans »

hinkley wrote: post #113
danans wrote: post #112

This could be a game changer for seasonal energy storage if it allows round trip efficiencies of even say 60%. Ammonia has been demonstrated as a fuel in existing natural gas turbines [1] at combustion efficiencies up to 99%. 1. https://nh3fuelassociation.org/2018/12/07/performance-of-amm... .

Highly caustic to delicate tissues however, such as lung tissue.

Undoubtedly, at the scales needed for seasonal energy storage, containment systems with multiple fail-safes would be needed. But if we can do that for nuclear reactors, it's got to be strictly simpler for ammonia.

Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#146

Post by hinkley »

danans wrote: post #145
hinkley wrote: post #113

Earlier quoted context omitted.

Highly caustic to delicate tissues however, such as lung tissue.

Undoubtedly, at the scales needed for seasonal energy storage, containment systems with multiple fail-safes would be needed. But if we can do that for nuclear reactors, it's got to be strictly simpler for ammonia.

Some early fridges ran on ammonia as the refrigerant. Didn’t survive scaling up to mass production. Neither has nuclear.

Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#147

Post by lambdatronics »

rational_indian wrote: post #37

>150 ± 20 nmol s−1 cm−2 Isn't this miniscule? Is this commercially viable? Edit: The molecular mass of nitrogen is 28, so 1 mol is 28 grams, so 150 nmol is 28 x150 nano grams = 4.2 micro grams. How much gas is this?

For hydrogen electrolysis they typically quote around 1 A/cm^2 current. One Coulomb is ~6e18 charges, whereas one mole is 6e23 molecules, so that makes about 1e-5 H atoms per cm per second. Of course making one molecule of ammonia needs 4 H atoms, so it works out to something like 16x lower productivity. I assume it's not competitive as is.

Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#148

Post by lambdatronics »

HPsquared wrote: post #3

What does the term "current-to-ammonia efficiency" mean here? I imagine it would refer to the specificity of the reaction, i.e. that 99% of the electrons passing through the system are used in the main reaction, and The abstract doesn't go into detail on energy efficiency and a comparison to the old method using gas. For instance, would this method result in less CO2 emissions using regular grid electricity, or would…

Probably refers to "Coulombic efficiency." Ie, it takes 4 electron transfers to turn 2 H2 + N -> NH4, so that gives you a conversion factor between Coulombs of electrons (1 Amp of current is 1 Coulomb per second) and number of NH4 molecules produced.

Yeah, someone would have to get access to the paper to see if they state the energy efficiency. I assume that b/c they don't mention it, it is abysmal. There's pressure to put good results into the abstract.

Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#149

Post by lambdatronics »

hn_throwaway_99 wrote: post #4

This would be a gigantic breakthrough if true and scalable, correct? Most ammonia production for fertilizer currently uses natural gas, and of clean sources of electricity with such a high yield of ammonia production would have a huge worldwide impact. So is there something I'm missing?

Probably not just yet. I calculated downthread that the productivity is something like 16x less per unit area than a hydrogen electrolyzer, so that would need to be improved to make it cost-effective probably. Also they don't mention the energy efficiency, only the "current efficiency" so I would assume the energy efficiency is also poor. Sounds like there's much to be done still.

Re: Nitrogen electroreduction with almost 100% current-to-ammonia efficiency (2022)

#150

Post by lambdatronics »

danans wrote: post #112

This could be a game changer for seasonal energy storage if it allows round trip efficiencies of even say 60%. Ammonia has been demonstrated as a fuel in existing natural gas turbines [1] at combustion efficiencies up to 99%. 1. https://nh3fuelassociation.org/2018/12/07/performance-of-amm... .

First you want to displace natural gas for fertilizer production. But yes, if the energy efficiency is good enough and the electrolyzer costs are very low, it would make more sense than electrolyzing hydrogen and then running that through Haber-Bosch. Remains to be seen if either of those criteria can be met.
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