Ammonia, nitric acid and nitrates

Looking more closely at the Haber process in practical terms, we note that, like sulfur trioxide formation in the contact process, it is an equilibrium reaction and also exothermic. 

It is interesting to note that the hydrogen required for the Haber process comes from an organic source — North Sea gas (methane). 

Two stages are needed, with the first known as steam reforming CH4(g) + H20(g) = CO(g) 3H2(g) 

These reactions take place at 750 °C, and are carried out over nickel-based catalysts. The water gas shift reaction is then employed to remove carbon monoxide and produce more hydrogen  

In practice this is carried out in two stages at 400 °C over an iron catalyst, and then at 200 °C over a copper one. Finally the carbon dioxide is removed by bubbling the gaseous mixture through either potassium hydroxide or diethanolamine solution. It is important that the oxides of carbon are reduced to a very low level otherwise they may poison the catalyst in the Haber process. 

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As shown in Table 1.1, the number of chemicals manufactured as bulk commodities is large. Consequently, in this account we have focused on just a few representative examples that embody the major considerations which underpin the operation of a viable manufacturing unit. These are sulfuric acid phosphoric acid ammonia, nitric acid and nitrates the chlor-alkali industry and the inorganic fluorine industry. 

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