Optimizing the Conditions for Ammonia Production Using Absorption

Ammonia is made from hydrogen and nitrogen over a catalyst operating at high temperature and pressure. More ammonia can be produced by changing how the ammonia synthesized is separated, i.e., by replacing the current condensation of ammonia with absorption in salts like magnesium chloride. This paper uses the concept of resistances in series in conjunction with experiments of absorption and a well-established theory of reaction to identify conditions where the rate of ammonia synthesis can be increased. For example, in one case, if a condenser in a conventional process is simply replaced with an absorber, the increase in production rate per mass of catalyst is capped at 10%. However, if the recycle rate is simultaneously increased, the increase in production rate per gram of catalyst can exceed 1000%.