What should be noted when resuming reduction after a disruption in catalytic reduction?
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This post was last edited by Kuju Keiko on 2011-1-8 at 23:21. During the previous heating and reduction process using the synthetic catalyst in beds 2 and 3, the hydrogen-nitrogen compressor failed suddenly; after repairs, the heating and reduction process was resumed. What should be taken into consideration by those working in the synthesis area? Thank you
There’s nothing to do – the worst thing that could happen has occurred. The only option is to raise the temperature again and reconnect the broken circuit. This kind of situation isn’t that rare. When raising the temperature, it’s necessary to control the rate carefully; the separator must be used to remove water, and it’s strictly forbidden for water to enter the tower. All other parameters should be maintained as they were before stopping. A representative from the manufacturer should be present when resuming operation; communicate more with them
The most important thing to prevent interruptions during the reduction of the synthetic catalyst is to maintain a certain level of venting at the outlet of the synthesis tower, thereby keeping the gases inside the tower in a forward-flowing state. This prevents the gases from re-oxidizing the already reduced catalyst, thus preserving its activity and strength. Secondly, it also prevents water vapor inside the synthesis tower from condensing due to temperature drops, which could dissolve the K ions in the catalyst and lead to a decrease in its activity. Secondly, it is important to control the rate of temperature and pressure reduction.
Sometimes things don’t work as people think; they can’t be replaced. Purging with nitrogen for protection is something to keep in mind when carrying out reduction again
There is no other choice but to shut down the furnace and the tower, maintain a constant temperature, and allow venting from behind the tower for some time in order to reduce the water vapor concentration and minimize the damage caused by water vapor to the ammonia catalyst. Once the compressor is repaired, the system can be restarted, the furnace can be turned on again, and the temperature raised.
After re-establishing the circulation, gradually increase the circulation volume, strictly control the temperature to prevent excessive temperature rise and loss of control, and enhance the discharge of reduced water to avoid the presence of water in it.