How does anhydrous ammonia work?

This manufactured chemical is made through the Haber-Bosch process that fixes hydrogen and nitrogen together by using a highly pressurized and heated catalyst plus an industrial reactor to make the chemical compound known as NH3. Keeping this manufactured chemical in a stable condition where it can be handled is imperative as it is very volatile and classified as an extremely hazardous material. Since anhydrous ammonia boils at -33.34°C, the temperature to pressure ratio is important to comply with as this will prevent accidents. For example, if the pressure tank is kept at 0° F then the pressure (pounds per square inch) should be 15.7psi. If the temperature is at 140°F then the pressure must be at 364.4psi.

Above is how the chemical physically works, as for its usefulness and how it contributes to productivity in our modern world, that’s a different matter. Anhydrous ammonia is a concentrated chemical compound that is used for a number of things including fertilizer, cleaning supplies (when diluted), and in some cases refrigeration. Anhydrous ammonia is produced on such a mass scale globally that it makes you wonder how we use it all. The answer is fertilizer; about 80% of what is made is used for that purpose since there is a large population that needs to stay fed. It is also much less expensive than other fertilizer options which is another reason why farmers use it so often.

Anhydrous ammonia for fertilizer works by the natural processed called nitrification. This is when the anhydrous ammonia is injected into the soil as NH3 and it quickly snags another hydrogen molecule making it into NH4 (ammonium).  Next the NH4 gets converted to NO2 (Nitrite) and with the addition of oxygen molecules it becomes NO3- (Nitrate). Nitrate is what plants use. Without this man-made nitrate product, corn farmers would probably have a much harder time trying to get things to be as productive.

The downside of using anhydrous ammonia is the argument that with the application of the chemical, the bacteria and fungi around the application site die. It is also argued that concentrated ammonia kills the earthworm population. This creates a sort of dead zone in the soil for a little while before the bacterial and fungal colonies can re-establish themselves.


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