Small-medium ammonia plant

The low-pressure renovation for the small-medium ammonia plant... 

However, in China the pressure of small to medium ammonia plants still exceed 30 MPa and the energy consumption of ammonia production is about 50% higher than the average international level. Such a situation is not consonant with the trend of development in the ammonia sjmthesis industry. Ironically, it is China that has already developed high activity catalysts that operate at low temperature and... 

In view of the in biting effect of oxygen in the corrosive action of the reaction - medium, small amounts of air are added to the carbon dioxide feed. This addition is claimed to allow the easier removal of certain impurities. However, if the CO2 employed is obtained from an ammonia plant, it must first be rid of the hydrogen it contains by catalytic oxidation, to avoid subsequent explosion hazards. 

It is well known that the conversion of hydrogen and nitrogen per pass is only 20%-30% for the present catalytic ammonia synthesis technology (Table 1.4). Most synthesis gases need to be returned to the reaction system, which increases power consumption. In order to increase conversion per pass, it must increase the outlet ammonia concentration of reactor. Accordingly, it can be seen from Table 1.4 that it is necessary to increase reaction pressure for small and medimn scale aimnonia plants and Topspe process, or to reduce the content of inert gas in sjmthesis gas for Topspe and Braun processes, or to reduce ammonia concentration in the inlet of converter for small and medium scale ammonia plants and Kellogg process. But all of these operations will add the power consumption or unit gas consumption. 

Processes Small and medium scale ammonia plants Kellogg Topsoe Braun ICl AMV... 

Therefore, in industrial installations, the reduction rate and quality of catalysts is ensured by the strict controlling of the concentration of water vapor. Generally, the vapor concentrations are limited in < (0.7 — 1.0) g/m for small and medium-scale ammonia plants, and <3.0g/m for large-scale ammonia plants. 

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