What are the hazards of water in syngas within the synthesis tower?
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Let’s all discuss it – is it related to catalysts?
It easily causes the synthetic catalyst to be oxidized repeatedly, leading to crystal growth. It affects catalyst activity.
Water carried in the syngas into the tower causes significant damage to the ammonia synthesis catalyst, potentially leading to its permanent poisoning. Therefore, it is necessary to avoid water vapor from entering the synthesis tower as much as possible.
It oxidizes the catalyst α-Fe to an oxide through adsorption at the active center, and this oxide can reduce and regenerate iron in syngas, thereby causing repeated oxidation-reduction of the catalyst. This process leads to the recrystallization of iron grains, and the irreversible growth of such grains results in a gradual decline in catalyst activity. Therefore, oxygen poisoning is a strong transient poisoning and a weak permanent poisoning. The effect of water vapor is similar to that of O2.
Catalytic oxidation, resulting in the loss of catalyst activity
This post was last edited by *aoye613 on 2010-2-5 22:16. The presence of water causes repeated oxidation and reduction of the catalyst in the synthesis tower, making it difficult to control the bed temperature; as a result, the catalyst crystals grow larger and its reaction activity decreases, eventually leading to permanent deactivation. It causes great harm
Water in the gas stream of the synthesis tower can cause the catalyst to become ineffective; in severe cases, it may lead to damage to the catalyst throughout the entire tower. Strict control is necessary during the production process; otherwise, the losses will be significant. The main principles have been clearly explained by those upstairs.
The last edit to this post was made by hongsheng_08 on 2010-2-7 at 22:41. Water in the synthesis tower can poison the catalyst; water is an oxide, and all oxides can cause oxidative poisoning of the catalyst； If that’s the case, the only option is to reduce the pressure, turn on the electric furnace, and raise the temperature of the upper layer to above 490°; maintaining this temperature for one shift should be sufficient to restore normal conditions.
As for the hazards associated with water in syngas, everything necessary has been covered earlier. Water is generated during the reduction process of the synthesis catalyst; if the catalyst has just been replaced, the reduction process may not have been completed thoroughly. Additionally, water in the feed gas might accumulate after entering the synthesis tower.
Water in the syngas, when it enters the tower, can cause the catalyst at the upper part to oxidize and lose its activity; in severe cases, it may even lead to caking of the catalyst, affecting the service life of the catalyst throughout the entire tower
Water is a poison for synthetic catalysts; it causes the catalyst to oxidize, leads to grain growth, and reduces its activity.