Ammonia processing routes, simplified

Application The Linde ammonia concept (LAC) produces ammonia from light hydrocarbons. The process is a simplified route to ammonia, consisting of a modern hydrogen plant, standard nitrogen unit and a high-efficiency ammonia synthesis loop. 

Allied Chemical recently proposed a simplified technique, producing caprolactam from cyclohexanone, ammonia and oxygen in a single step, in the vapor phase, on a sffica or alumina-based catalyst However, the drawback of this process resides in the fact that only half of the oxime is converted in situ to caprolactam. This makes it necessary to resort to the Beckmann rearrangement For a 50 per cent conversion of cyclohexanone, the molar selectivity of oxime and caprolactam is 68 per cent Although this method considerably reduces the production of ammonium sulfate, the yields are still too low for it to appear to be more economical than the foregoing routes. 

In the development of the steam-reforming route to ammonia, for many years there has been a desire to eliminate the steam-reforming furnace for reasons of capital cost, efficiency, and reliability. This technology has now been demonstrated on a commercial scale by ICI with the LCA process. With this process the plant is simplified by the use of a Gas Heated Reformer (GHR) in which the primary reformer receives heat directly from the process gas leaving the secondary reformer. This compact pressurized reformer eliminates the massive furnace structure and the high-pressure steam system of a conventional plant. A pressure swing adsorption... 

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