If high pressure increases the yield of ammonia, why is the pressure not raised further still?

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Question

If high pressure increases the yield of ammonia, why is the pressure not raised further still?

Accepted Answer

Because stronger vessels and more powerful pumps cost more and raise the safety risk — Award 1 mark. The chemistry would favour an even higher pressure, but the economics and safety do not, so the operating pressure is a compromise between yield and cost rather than a chemical limit.

Answer

Because the catalyst stops working above 200 atmospheres

Answer

Because higher pressure would make the reaction irreversible

Answer

Because stronger vessels and more powerful pumps cost more and raise the safety risk

Answer

Because ammonia decomposes at pressures above 200 atmospheres

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