The active uses of an inert gas

Most of an organic chemist’s work is done in various phases of the liquid and solid states. Reactants and reagents go into the flask or the reactor, the chemistry is done in the solution phase, and ideally the produce is immediately crystallised out. Sure, there is the odd reaction that generates gases, like diazotisation reactions. There are also some reactions that use gases like chlorine as a reagent. However, most days in our plant, gases do not take part much in the chemistry.

That’s not to say gases are unimportant. One in particular has many important roles to play: nitrogen. The most common reason to use nitrogen is the most obvious – we’re using it to make sure oxygen and a spark don’t start a combustion reaction with the solvents we use, which are typically fantastic fuels for fires. This creates a very significant nitrogen demand – 24 hours a day, our reactors have just enough nitrogen flowing above the reactions stirring below to keep oxygen out and keep our chemical operators safe.

It’s not just fire prevention where nitrogen is useful in the plant. Have solid product stuck in a bottom valve? Pump in nitrogen to blow the chunk of product out of the way. Want to provide a little agitation to a reactor where the main agitator is off? Nitrogen up the bottom valve can help with that as well. And if you can’t distil a reaction by heating it, you can often sparge out some solvent by blowing nitrogen pressure through the reaction mixture.