Nitrogen
Seventy-eight percent of the air, almost entirely unreactive, and the element whose industrial fixation roughly doubled the number of people the planet can feed.
Nitrogen makes up most of the atmosphere and is nearly inert, because the triple bond holding N₂ together is one of the strongest in chemistry. Life needs nitrogen in reactive form, and breaking that bond is the bottleneck.
The Haber–Bosch process, developed in the early twentieth century, breaks it industrially at high temperature and pressure. Around half the nitrogen atoms in a typical human body have passed through it. Few industrial processes have had a comparable demographic effect.
Environmental impact
Ammonia synthesis consumes a substantial share of world natural gas production, and reactive nitrogen that runs off farmland drives algal blooms and coastal dead zones. The process that made abundant food possible is also one of the larger perturbations humans have made to a planetary cycle.
Uses
Most nitrogen goes into ammonia, and most ammonia goes onto fields. Synthetic nitrogen fertiliser is the reason the world can feed its current population, and it is difficult to name another industrial process with a comparable effect on human numbers.
The gas itself is used wherever oxygen must be excluded: blanketing fuel tanks, packaging food, purging pipework. Liquid nitrogen is the cheap, everyday cryogen — cold enough for most laboratory purposes and, unlike helium, effectively unlimited.
How we know: checked recently · only one source, so there is nothing to cross-check it against · stated directly by the source.
How this connects
Where a connection has been confirmed by an outside reference, that reference is named beside it.
is used as
- Fertiliser — application · the N in N-P-K, fixed from the air by Haber-Bosch
is produced by
- Air separation — process · the most abundant component of air and the first to boil off
is an alternative to
- Argon — element · as an inert atmosphere. Nitrogen is far cheaper and not truly inert — it reacts with titanium, magnesium and molten steel — so argon keeps the work where that matters
is found in
- Air — material · 78% · roughly seventy-eight per cent by volume, and effectively inert — which is why it can be the bulk of what everything breathes
- Nylon — material · the element that makes it a polyamide — the same linkage that joins amino acids into protein, which is why nylon is strong for the same reason silk is
- Wool — material · in the amide links — wool is a polyamide, which is the same linkage nylon uses
- Silk — material · fibroin is a protein, so the chain is joined by the same amide link as nylon and wool
- Leather — material · collagen is a protein, and tanning cross-links it rather than replacing it
- ABS — material · in the acrylonitrile, and the source of the chemical and heat resistance the other two do not supply
- Aramid fibre — material · in the amide links — the same linkage as nylon and as protein, on a stiff backbone
- Epoxy resin — material · in the amine hardeners that cure most systems — and the component responsible for the sensitisation risk
- Polyurethane — material · in the urethane link, contributed by the isocyanate — the component that is hazardous before cure and inert after it
- Silicon nitride — compound · four, in covalent bonds strong enough that the atoms barely diffuse — which is why it is so hard to sinter
- Gallium nitride — compound · the other half, and the strong Ga–N bond is what makes the band gap wide
Sources
- Material WorldOur own writing
- Wikimedia Foundation · Creative Commons CC0 1.0 Universal (public domain dedication)
- US National Library of Medicine · Mixed — aggregated third-party content, rights retained by depositors
- United States Department of Commerce · US Government work — public information, credit requested