Friday is here, and the weekly column 'A Taste of Science for the Weekend' is back — issue 58.
This week: what makes ammonium nitrate such an effective fertilizer, yet also an exceptionally dangerous and deadly explosive.
---
If ammonium nitrate sounds familiar, you're not wrong.
It is most likely the substance responsible for the massive explosion in Beirut in 2020, which devastated the port area and caused damage across a radius of many kilometers.
According to reports, the blast originated from 2,750 tonnes of ammonium nitrate that had been improperly stored.
Beyond its power as an explosive, it is also widely used as a fertilizer for agricultural crops. Its legitimate civilian use makes it considerably harder to detect those who acquire it with malicious intent.
---
Nitrogen is one of the fundamental building blocks of life on Earth, as organic compounds such as proteins and DNA rely on it as an essential component.
Although roughly 80% of the atmosphere is nitrogen, it occurs in the form of paired nitrogen atoms that are extremely difficult to separate.
Certain soil bacteria are capable of breaking it down into ammonia (nitrogen and hydrogen), while other bacteria convert ammonia into nitrite (one nitrogen atom + 2 oxygen atoms) and nitrate (the same as nitrite, but with 3 oxygen atoms).
This product serves as a vital nutrient for plants, and subsequently for the animals that eat them.
---
Ammonium nitrate combines ammonia (nitrogen and hydrogen) with nitrate (nitrogen and oxygen), arranged in a crystalline structure similar to table salt.
Ammonium nitrate can today be produced in the laboratory in large quantities and at low cost, making it a far more efficient and cleaner fertilizer than the cow manure traditionally used for this purpose, which contains a much lower concentration of nitrogen.
The danger of the compound lies in the fact that it contains both nitrogen — which can be rapidly released as a gas when heated — and oxygen, which can feed the combustion process.
When ammonium nitrate is exposed to high heat or fire, it decomposes while releasing energy, generating gas that expands rapidly through the surrounding space, along with oxygen that continues to sustain combustion even without any external oxygen supply.
As a result, it is considered a popular explosive in industry and in the manufacture of fireworks, but also a favored explosive among terrorists, who can claim if necessary that it was intended for use as a fertilizer.
Following a number of disasters caused by improper storage, regulations have been established governing how the material must be handled and stored.
The warehouse in Beirut apparently did not comply with these safety requirements — and so set in motion one of the most devastating, yet also most visually striking, explosions we have ever witnessed.
Shabbat Shalom ☺️
#ATasteOfScienceForTheWeekend (#ATasteOfPhysics formerly)