Problems with hydrogen production catalysts
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I would like to ask fellow sailors: After the reduction process is completed for the first time with a hydrogen production catalyst, can a nitrogen and steam circulation be carried out over an extended period of time? What is the maximum temperature that can be controlled at the converter outlet at this time?
Hydrogen production begins with a nitrogen cycle. When the temperature at the outlet of the converter reaches 400°C and the steam produced is of satisfactory quality, hydrogen is introduced into the system. When the temperature rises to 650°C, hydrogen reduction starts; the reduction process continues until the temperature reaches 750°C, at which point 8 hours have passed since the start of reduction. At this point, feeding can begin, and it is now a hydrogen cycle rather than a nitrogen cycle. If you are concerned about issues related to the transition to production, you can control the rate of temperature increase properly. It’s not possible to use hydrogen reduction; one has to wait for a while. After all, that process takes basically 10 hours regardless of anything else. If feed is added again and PSA is used, it will take around three hours as well.
Of course, but the catalyst needs to be reduced again before feeding it, and the temperature at the outlet of the converter must be lower than that during reduction; otherwise, it will be difficult to reduce the catalyst.
A nitrogen and steam cycle is feasible; as mentioned above, it is necessary to carry out re-reduction, or the outlet temperature of the conversion process is lower than the operating temperature. In a nitrogen cycle, full-volume circulation is generally used, and the pressure should not be too high – it should be around 0.5 MPa at the inlet. Otherwise, if the system pressure is too low, nitrogen cannot be supplied into the system. If you are waiting to start operation, it is entirely possible to use nitrogen and hydrogen for circulation, take the hydrogenation reactor out of service, and simply wait for the feeding condition to be reached; as soon as feeding begins, operations can start immediately. I hope this can be helpful to you
No problem – today’s catalysts have improved oxidation resistance, and their ability to separate from active metals has greatly increased