ICI-AMV process

ICI AMV Process. The ICI AMV process [1034], [1083], [1111] - [1122], also operates with reduced primary reforming (steam/carbon ratio 2.8) and a surplus of process air in the secondary reformer, which has a methane leakage of around 1 %. The nitrogen surplus is allowed to enter the synthesis loop, which operates at the very low pressure of 90 bar with an unusually large catalyst volume, the catalyst being a cobalt-enhanced version of the classical iron catalyst. The prototype was commissioned 1985 at Nitrogen Products (formerly CIL) in Canada, followed by additional plants in China. A flow sheet is shown in Figure 110. 

ICI 74-1 catalyst which contains cobalt has been successfully developed, and applied in the low pressure ICI-AMV process by ICI. The catalyst used in this process is ICI 74-1. The diameter of the converter is 2.9m, with the height of 24m. The volume of the catalysts is 96 m (250 tons in weight) in total, which is separated into three catalyst beds. The operation conditions are Pressure of 10 MPa, temperature of 450°C, space velocity of 5,00h net value of ammonia (10%-11%) and pressure drop of 0.4 MPa. The content of inert gases such as methane is limited to about 7%. The reduction temperature at which water is produced is 370°C. The highest reduction temperature is about 480°C. In Hainan Fudao Fertilizer Plant of China, the volume of the catalyst of the converter is increased to 122.4 m in Ude-ICI-AMV process. 

The A2 series of catalyst has been used in ICI-LCA and ICI-AMV processes. The AMV is the process used in the Zhongyuan Fertilizer Plant. The ammonia... 

The ICI-AMV process was developed by the ICI Company for its 74-1 Fe-Co catalyst, where the process was designed by ICI and the engineering was designed by Uhde Company, Germany. The core of the synthesis loop at low-pressure is the radial-flow converter with three beds of catalysts using 74-1 catalyst of small-particle and indirect interchanger, and in series an inverted U-shaped waste heat boiler. " The process flow is shown in Fig. 9.5. The main technical parameters are shown in Table 9.2. 

As with the processes already discussed, the ICI AMV process is based on steam reforming of either natural gas or naphtha. It uses the same basic process steps as the Kellogg or Topsoe processes, but the operating conditions are significantly different. 

There has been an immense amount of research into variations of the original Haber catalyst first used commercially. Current catalysts have been improved so that commercial plants using the ICI AMV process operate at 70-80 atm pressure. The bed exit temperatures are still above 400 °C because of the equilibrium properties of nitrogen/hydrogen mixtures (see Appendix 5) and the reaction-rate requirements. The development of high-activity catalysts could lead to significant reductions in temperature and pressure, and consequent savings on capital and fuel costs. 

The synthesis pressure has, as mentioned above, an important influence on the performance of the ammonia synthesis loop because of its influence on the reaction equilibrium, reaction kinetics, and gas/liquid equilibrium in the product separation. A wide range of operation pressures has been used in practice, from less than 100 bar (in the early Mont Cenis process and recently in the ICI AMV-process) to 1000 bar (in the early Claude and Casale processes). The trend in modern plants has been to select operating pressure in the low to medium pressure range typical operating parameters for modern synthesis loops at two different pressures are given in Table 6.1. 

The most notable development for the magnetite system was the introduction of cobalt as an additional component by ICI in 1984 [395], [396]. The cobalt-enhanced catalyst formula was first used in an ammonia plant in Canada using ICI Catalco s AMV process (later also in other AMV license plants) and is also successfully applied in ICl s LCA plants in Severnside. 

For the improvement of synthetic quotient per pass, it is also an effective approach to increase volume of catalyst in order to reduce space velocity such as ICI-AMV and Braun processes. 

The ICI AMV design is an overall process in which the operating conditions of the individual process steps have been optimized to complement each other. This can be demonstrated by describing a typical AMV flowsheet. 

C. W. Hooper and A. Pinto, Development and Operation of the ICI AMV Ammonia Process, Fertilizer Industry Annual Review, XI, p. 61 (1988). 

For example, Braun purifier process and AMV process (ICI) — bodi wifii increased duty of secondary reformer. 

ICI has been active in the design and operation of ammonia plants since before the Second World War. In recent years, they have commercialized two processes namely the AMV process, and the LCA process. 

AMV A modified process for making ammonia, invented by ICI and announced in 1982. It uses a new catalyst and operates at a pressure close to that at which the synthesis gas has been generated, thereby saving energy. Construction licenses have been granted to Chiyoda Corporation, Kvaeme, and Mannesman. In 1990 it was operated in the CIL plant in Ontario, Canada and then in Henan Province, China. 

Development work was successful and, following a typical fusion production procedure, the new catalyst could be reduced and operated at lower temperature under normal conditions in conventional plants. Reduction began at 380°C in the new AMV and LCA processes introduced by ICI in 1985 and 1988 respectively. The AMV plants have operated at more than 100% capacity of a pressure of only 60 bar. The life of the new catalyst has been very satisfactory, and could be operated of pressures much closer to those of the reformers, albeit with large converters. 

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