Thread: 100% pure Nitrogen for Haber Process?

Hello, I have been doing research for a research assignment on Haber process, and a glaring contradiction.

A few websites claims that 100% pure Nitrogen obtained through fractional distillation is necessary for fractional distillation.

Other website do not mention and instead claims that air is used. (they react the oxygen to form water to get rid of water)

Which is right?

Thanks in advance.

They might both be right. Nitrogen can be obtained by liquefying air and then fractionating it. Nitrogen can also be obtained by burning hydrogen in air and condensing out the water that’s produced. The latter method would not produce 100% pure nitrogen but it could be cleaned up in further processing.

Using air instead of nitrogen in the Haber process would not make economic sense because the partial pressure of nitrogen would be much lower, slowing the reaction rate, and the size of equipment would be much larger to handle the large volume of air compared to the much smaller volume of nitrogen. Reactors designed for 200 bar should as small as possible, or they become tremendously thick, heavy and expensive.

Here's an example of a complete ammonia production plant using nitrogen from a cryogenic air separation unit (ASU).

http://www.uop.com/objects/FarmlandsGasif.pdf