Production of ammoniaIn 1910, a U.S. patent for the Production of Ammonia was issued to Fritz Haber and Robert Le Rossignol (No. 971,501). This process could produce ammonia on a large scale directly from its component gases, hydrogen and nitrogen, by passing a mixture of them over heated finely-divided osmium metal used as a catalyst. A typical pressure of 175 atmospheres and a temperature of 550ºC could easily give an 8% by volume yield of ammonia. Although nitrogen makes up 80% of the air, as a gas it is quite unreactive. Despite its ready availability, nitrogen gas had previously been difficult to combine in a chemical form. Once nitrogen has been chemically combined in the form of ammonia, many other nitrogen compounds can be made.« |
