11–20 of 133 posts
I grew up on an organic orchard, so don't get excited about artificial sources of nitrogen for agriculture and horticulture. It is better than getting fertiliser from fossil fuels, but it is still not great. My mind goes to energy storage. If it was a smart way to do that, people would probably be doing it, who knows. Well, someone wrote a paper about it in 2022: https://www.sciencedirect.com/science/article/abs/pii/…
So basically: wind generators power electrolysis to create hydrogen, the hydrogen is fed to a normal Haber-Bosch plant which is still powered by coal or gas. So basically the wind power is just replacing the carbon footprint of a single input (hydrogen) to a H-B plant?
There are press releases which link to other press releases. Found the technical paper from 2021.[1] The ammonia plant is built for intermittent operation, so it can shut down or reduce output when there's no wind. No need to store much electrical energy. Storage tanks hold the ammonia. It's a reasonable idea, but is it cost-effective? No numbers are given. Still, fertilizer independence alone is worth something. You…
I grew up on an organic orchard, so don't get excited about artificial sources of nitrogen for agriculture and horticulture. It is better than getting fertiliser from fossil fuels, but it is still not great. My mind goes to energy storage. If it was a smart way to do that, people would probably be doing it, who knows. Well, someone wrote a paper about it in 2022: https://www.sciencedirect.com/science/article/abs/pii/…
I grew up on an organic orchard, so don't get excited about artificial sources of nitrogen for agriculture and horticulture. It is better than getting fertiliser from fossil fuels, but it is still not great. My mind goes to energy storage. If it was a smart way to do that, people would probably be doing it, who knows. Well, someone wrote a paper about it in 2022: https://www.sciencedirect.com/science/article/abs/pii/…
https://fred.stlouisfed.org/series/DHHNGSP
The cost of wind power and solar power have fallen dramatically, but without accounting for the externalities of CO2 emissions, natural gas is still the cheaper way to make ammonia.
It would be interesting to get details what’s the process behind. Can you reproduce it on personal level?
Fritz Haber initially demonstrated his process producing 125 milliliters per hour of ammonia in a "tabletop machine", so it's obviously technically possible. Typical process parameters are about 200 bars and 500 degrees C, so it's not trivial but also not outside of what a dedicated hobbyist could reach. I'm pretty sure it's not economically feasible at small scales though. Even the earliest industrial plants in the 1920s made 20 tons of ammonia per day. It will be vastly cheaper to just buy the stuff in bulk from a plant churning out hundreds of tons per day than it will be to make it yourself at a rate of 2 liters per day.
That said, go for it! A factory is just a room, and similarly a chemical reactor is basically just a steel drum.
In other words, to split 1 mole (18 grams) of water into constituent parts (molecular hydrogen and oxygen), you need to invest at least 300 kJ of energy. If you then use 1 mole of hydrogen to produce ammonia, you can get back 30 kJ of energy.
This is chemically pretty much the best case from the thermodynamic efficiency standpoint (especially when you also factor in the entropy changes) with almost zero potential waste.
The kicker is, of course, that you need extremely high temperature and pressure for the reaction to work. And this is just hard to do on small scale. But that's not a theoretical barrier, but "just" a question of clever engineering! It's great to hear that we're solving these issues.
Perfect project for rural Minnesota, that needs the ammonia, but also has a surprising amount of solar colocated with farms. And a fair amount of wind in the southwest. However there are far far larger projects going on over the world. China is building multiple GW of wind and solar to power a massive ammonia/green hydrogen site right now. I frequently hear of sites in Spain in the hundreds of MW range. The US has be…
The US isn't a centrally planned economy (sort of) so the more economical option wins.
So basically: wind generators power electrolysis to create hydrogen, the hydrogen is fed to a normal Haber-Bosch plant which is still powered by coal or gas. So basically the wind power is just replacing the carbon footprint of a single input (hydrogen) to a H-B plant?
Why would the HB plant be powered with fossil fuels? You can power that with wind power as well.
Perfect project for rural Minnesota, that needs the ammonia, but also has a surprising amount of solar colocated with farms. And a fair amount of wind in the southwest. However there are far far larger projects going on over the world. China is building multiple GW of wind and solar to power a massive ammonia/green hydrogen site right now. I frequently hear of sites in Spain in the hundreds of MW range. The US has be…
Fossil fuels remain more cost effective. The US isn't a centrally planned economy (sort of) so the more economical option wins.