What is the difference between medium-variant iron catalysts and synthetic iron catalysts?
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Do medium-variant and synthetic iron catalysts differ in structure after reduction? Please help answer it, guys
The structure and additives of the two catalysts differ, but the main difference lies in the active components after reduction: medium-pressure – Fe2O3, ammonia synthesis – α-Fe
Reply to 1# Xingyue: The main difference lies in the active components resulting from the reduction of the two catalysts: medium temperature conversion – Fe3O4, ammonia synthesis – α-Fe
The oxidation state of the medium-temperature catalyst (its oxidation state at the time of manufacture) is that of iron oxide; the promoters include chromium oxide, potassium oxide, etc., which are reduced to iron oxide tetraoxide, thereby catalyzing the conversion reaction. The oxidation state of the synthetic catalyst (its oxidation state at the time of manufacture) is that of iron tetraoxide; the promoters include aluminum oxide, potassium oxide, calcium oxide, etc., which are reduced to elemental iron, thereby acting as a catalyst for the ammonia synthesis reaction.
The low-temperature condensate contains ammonia nitrogen, whose main source is the medium-temperature converter. What I want to know is: how can the amount of ammonia generated be calculated in a medium-temperature converter operating at 2.8 MPa, 400°C, and with a high water vapor concentration?
The low-temperature condensate contains ammonia nitrogen, the source of which is primarily the gasification furnace; trace metal elements present in the feed coal can act as catalysts in the gasification furnace to convert H2 and N2 into NH3.
There is no over-reduction in ammonia synthesis catalysts, whereas when medium-temperature shift catalysts are over-reduced to Fe, they remain catalytic for the Fischer-Tropsch reaction but lose their catalytic activity for the shift reaction.