Sudden shutdown of the reformer hydrogen generator
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The reformer hydrogen pump stopped suddenly; the furnace was shut down and hydrogen was added along with feedstock, containing oil. Where does this hydrogen come from? If the pre-hydrogenation hydrogenator tut is taken out, does it still be necessary to maintain the circulation gas volume with oil present?
The conventional approach to dealing with a sudden stop of the reforming cycle machine is to leave it running without using hydrogen gas for displacement； Recent designs of reformation units include a interlock for low-flow combustion mode; once the circulator stops, hydrogen from the compressor outlet can be directed to the inlet of the heat exchanger to establish a low-flow circulation, thereby protecting the heat exchanger and the components inside the reactor. Relevant documentation can be consulted for more details. Pre-hydrogenation circulators usually have backup units, which can be brought online in a short time to resume production; if the backup unit cannot be started, then penalties are inevitable
I basically agree with the opinion above: when cyclic hydrogen production stops, it’s necessary to identify the cause as quickly as possible and restart the system promptly. Generally, few companies have spare centrifugal compressors available; if such a stop occurs and hydrogen supply to downstream processes is interrupted, it’s no trivial matter. Hot hydrogen with oil is usually applied during shutdown for maintenance; the gas supply is generally drawn from the pipeline network
If oil is not carried by hydrogen, will the oil and gas in the reactor bed and pipelines cooling down to a liquid state cause damage to the catalyst and sludge?
Proven in practice, the device was left idle during a major power outage for 30 hours, and there were no issues after it was restarted. However, it is necessary to run a cold-state cycle of the catalyst to prevent damage to the internal components caused by differences in the cooling rates of those components and the catalyst ； For the low-flow combustion mode, it is best to establish a circulating oil supply to protect the heat exchanger plates.
Shutting down the reforming cycle hydrogen compressor and the pre-hydrogenation cycle hydrogen compressor are completely different handling methods; the principle for reforming is to maintain temperature stability and avoid damaging the components inside the reactor. The principle for pre-hydrogenation treatment is to prevent the reactor temperature from spiking.
After the reforming cycle machine trips, the unit adopts a holding strategy to maintain system pressure (or increase the high-pressure level), thereby preventing excessive coking of the catalyst; simultaneously, the flue dampers of the heater are adjusted to slow down the rate of temperature drop. Stop the hydrogen delivery, shut down the cryogenic system; cease circulation, regeneration, and reduction processes, and close all isolation valves. The distillation system maintains pressure and liquid level while waiting to recover. After dealing with this issue in this device, the compressor was restarted and production resumed without any major abnormalities.