• CrimeDad@lemmy.crimedad.work
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    1 year ago

    Everyone seems to be focused on electricity production, but ammonia production (ie nitrogen fixation) for fertilizer is often overlooked. Right now it is accomplished mostly with natural gas. If we’re supposed to do it instead with wind and solar, we’re going to have to rely on simple and inefficient electrolysis of water to generate the hydrogen needed for the Haber process. Nuclear power plants have the advange of producing very high temperature steam, which allows for high temperature electrolysis, which is more efficient.

    When you consider our fertilizer needs, it becomes clearer that nuclear power will have to play the predominant role in the transition away from fossil fuels.

    • schroedingershat@lemmy.world
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      1 year ago

      No on all fronts.

      The only reactor designs with any sort of history don’t produce steam at high enough temperature for the sulfur cycle and haber process.

      The steam they do produce costs more per kWh thermal than a kWh electric from renewables with firming so is more economic to produce with a resistor.

      Mirrors exist. Point one at a rock somewhere sunny and you have a source of high temperature heat.

      Direct nitrogen electrolysis is better than all these options. It’s had very little research but the catalysts are much more abundant than hydrogen electrolysers and higher efficiencies are possible.

      Using fertilizer at all has a huge emissions footprint (much bigger than producing it). The correct path here is regenerative agriculture, precision fermentation and reducing the amount of farmland needed by stopping beef. Nitrogen electrolysis is a good bonus on top of this.

      • CrimeDad@lemmy.crimedad.work
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        1 year ago

        One way or another, I’m pretty sure that we need fertilizer. What is the source of GHG if the fertilizer is produced without natural gas or other fossil fuels?

        • schroedingershat@lemmy.world
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          1 year ago

          NO2, methane from byproduct/digestion, soil carbon release from land overuse. Downstream methane release due to nitrate pollution.

          The overwhelming majority of cropland is for “biofuel”, industrial chemicals and animal feed.

          Industrial scale regenerative agriculture has lower yields in the short term, but doesn’t emit NO2 and leave behind a dust bowl (requiring clearing a new forest).

          Eating crops directly rather than feeding cows is far more effective than changing fertilizer source. Eating organic crops uses a small fraction of the crop land that eating beef fed on intensively grown corn does.

          Biointensive methods have many times the yield as industrial agriculture but are very labour intensive – automating them would save a lot more emissions.

          Precision fermentation uses a tiny fraction of the land per unit of protein/nutrients.

          • commie@lemmy.dbzer0.com
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            1 year ago

            Eating crops directly rather than feeding cows is far more effective than changing fertilizer source.

            cows eat a lot of grass, and usually from land that isn’t suitable for crops. the silage they get is mostly parts of plants that people can’t or won’t eat.

            • schroedingershat@lemmy.world
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              1 year ago

              Paltering.

              Corn and soy grown for the purpose of large animal feed exceeds the amount of cropland used directly for human consumption in areas where <20% of calories and protein come from red meat.

              • commie@lemmy.dbzer0.com
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                1 year ago

                almost all soy (about 85%) is crushed for oil for human use. the vast majority of what’s fed to animals is the industrial waste from that process.

                only 7% is fed directly to animals.

                i don’t know the numbers for corn, but i do know that globally, about 2/3 of all crop calories go to people.

              • commie@lemmy.dbzer0.com
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                1 year ago

                almost no soy goes to cattle at all. calling me “paltering” while jumping from one segment of agriculture to another is just hypocritical rhetoric. try addressing the topic instead of characterizing me.

    • MonkCanatella@sh.itjust.works
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      1 year ago

      Yes, we’re definitely going to have to set up more nuclear power plants specifically to make fertilizer. Nuclear heads are literally brain dead

      • schroedingershat@lemmy.world
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        1 year ago

        Fertilizer which they can’t make because the steam isn’t hot enough.

        Every single pro nuclear argument is a fractal of terrible ideas and gaslighting.