Debottlenecking the Ammonia Synthesis Reactor System with the aid of Attainable Region Theory

Attainable Region theory is used to define the bounds of the operating region where an improvement in the productivity of ammonia is realised. An iso-productivity plot is used in conjunction with the results obtained from the attainable region to define a region of increased productivity. The objective is to determine the operating conditions under which the existing reactor system can handle increased productivity. This system consisted of a single reactor and a feed-product heat exchanger. The reactor system was modelled using the modified Temkin reaction scheme. A counter-intuitive result showed that an increased production rate of ammonia is associated with a decrease in conversion. Analysis of the results showed that a 10% increase in feed flow rate could possibly result in a 9% increase in productivity. It was found that the only way to increase the productivity of an existing reactor is to decrease the residence time. The results also showed that increasing the temperature need only be considered when implementing large increases in feed flow.