Problems with the use of ammonia synthesis catalysts
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I would like to ask whether it is appropriate to maintain a temperature of 510 degrees for the catalyst in an ammonia synthesis tower after three years of use. How long is the typical service life of a catalyst?
When the operating temperature reaches 510°C, it is already in the later stage of the catalyst’s life cycle. The typical service life of ammonia synthesis catalysts is 3 to 5 years; however, most plants now use methanol synthesis and hydrogen extraction technologies, which allow these catalysts to last 7 or 8 years.
Is production done with an electric furnace? Is the pressure for synthesis high? If both of the previous issues are present, the synthetic catalyst should be replaced.
The ammonia synthesis catalyst is reaching the end of its useful life; it’s best not to keep using it. The savings from producing less ammonia, along with reduced electricity consumption, far outweigh the cost of replacing the catalyst. . . .
Generally, synthetic ammonia catalysts are supposed to last about 5 years, right? At 3 years, it reaches 510°C – this is likely due to an excessive production load. The figures provided by manufacturers generally indicate that one ton of catalyst can enable the production of 10,000 tons of product. In fact, given the situation at your factory, it would be more cost-effective to replace the catalyst.
Pressure is 26.5 MPa; the electric furnace is not yet installed. Please give your advice
The service life and replacement of catalysts should be based on scientific replacement criteria established according to the enterprise’s production conditions, rather than being determined simply by one or two indicators； Common criteria for determination include: 1. The type of catalyst and the corresponding operating conditions (different catalyst types have varying active temperature ranges, and the operating conditions differ at different times) ； 2. Catalyst activity (reaction rate of the catalyst, thermal equilibrium of the system) ； 3. Net ammonia value (conversion rate of ammonia synthesis) ； 4. System pressure conditions corresponding to production load, and the utilization level of the enterprise’s processing capacity ； 5. Enterprise production cost control (consumption of various materials) ； 6. The purification status of the enterprise, as well as the duration of catalyst use, all determine the enterprise’s decisions regarding catalyst usage. The catalyst used by the poster has a relatively high temperature, and this will affect the electricity consumption associated with your production ； However, if the A110 series catalyst is chosen, the gas purification performance of the enterprise will not be very good, and a higher starting temperature for the catalyst will be required. The enterprise’s other equipment can continue to operate as long as no maintenance is needed at present. In short, this is a variable that should be determined objectively based on the actual conditions of the enterprise.
The service life of a catalyst is generally 3 to 5 years. The length of this service cycle depends on factors such as the effectiveness of gas composition control in the preceding stages, the stability of tower operations, the number of start-up and shutdown cycles, and the control of temperature changes. To determine whether the catalyst has reached the end of its useful life, it is necessary to consider not only temperature but also pressure, production volume, whether the amount of fresh gas required per ton of ammonia produced increases, whether the pressure difference in the synthesis tower rises, and whether hot spots in the catalyst layer shift downward. If the catalyst has indeed lost its activity, it should be replaced immediately.