After the shutdown, does the catalyst need to be reduced again before restarting?
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After a natural gas-based hydrogen production plant is shut down and restarted, does the catalyst need to be reduced again? Is the heating rate still the same as when we first did the debugging?
After a natural gas-based hydrogen production plant is shut down and restarted, the catalyst generally does not need to be re-reduced. The reduction of the catalyst is carried out upon its initial use, with the purpose of removing oxides from the catalyst surface to restore its activity. During the shutdown period, the catalyst is usually stored under an inert atmosphere and does not continue to oxidize; therefore, no reduction treatment is required when restarting the plant. As for the heating rate, it generally needs to be adjusted according to specific circumstances when restarting the device. If the device is shut down for an extended period, it may be necessary to raise the temperature gradually to avoid damage to the catalyst caused by sudden temperature increases. However, if the shutdown time is short, it can be considered to proceed at a heating rate similar to that during initial commissioning. The specific heating strategy is generally determined based on the device’s process and operational experience. .
Do you have any information on devices for raising the temperature while driving? Could you send me one?
On our end, it needs to be restored; 12 hours of restoration is required each time work starts
What is the size of the device on your end? Could you send me detailed information on temperature rise and reduction?
30,000–40,000 standard liters; the catalyst for the conversion reaction is nickel oxide, which is reduced to elemental nickel during production, and under conditions of hydrogen concentration above 75%, an inlet temperature of 350 degrees, and an outlet temperature of 720 degrees, the reduction process takes place over 12 hours
Our natural gas hydrogen production unit has a capacity of 600 cubic meters
Looking at the catalyst maintenance requirements, in some cases the catalyst becomes passive as soon as operation stops, and it needs to be reduced again before operation can resume after it becomes passive. If it is nitrogen retention and the catalyst has not been in operation for long, passivation may not be necessary
There seems to be some issue with the starting and stopping of your device; it needs to be optimized by an expert. If this catalyst is operated with natural gas, it usually does not require reduction.
We have several types of raw materials, and most of those used in driving are C5
In the case of starting up with C5 feedstock, a pre-reformation reactor is installed in the hydrogen production unit. Normal hydrogen dosing during startup is sufficient; this hydrogen dosing prior to feeding the feedstock serves a reducing function, eliminating the need for a separate, prolonged reduction process. The hydrogen molar ratio is 1.5%–3%.