How is coking in hydrogen production converters usually dealt with?

If coking occurs in the furnace tubes, if it’s not severe, increase the processing volume and adjust the water-to-carbon ratio to burn for a while; if it is severe, stop feeding material, introduce nitrogen gas, slightly reduce the temperature, and burn under normal operating conditions while measuring the levels of carbon monoxide and carbon dioxide in the gases

It depends on the pressure difference at the outlet of the converter; general carbon deposition only affects the catalyst’s activity and the purity of hydrogen in the conversion gas. Reduce or stop feeding, increase the water-to-carbon ratio, and burn charcoal. If the pressure difference is large and carbon deposition is severe, in order to protect the furnace tubes, it becomes necessary to consider replacing part of the catalyst. This is just my personal opinion; please forgive any shortcomings.

Mild carbon deposition can be appropriately cleared by flushing with the feed gas

Whether it is severe can be determined based on the color of the furnace tube, the outlet pressure difference, and the methane content in the converted gas. Common treatment methods: (1) Reduce the amount of raw material and produce with a high water-to-carbon ratio to see if there is an improvement. (2) Cut off the raw material and burn the carbon with steam. (3) Stop production to replace part of the furnace tube catalysts or all of the catalysts. (1) and (2) yield good results in terms of carbon deposition across the entire furnace, but when carbon deposition occurs only in one or a few furnace tubes, the effect of flow redirection is not very effective. Whether shutdown is required for handling usually depends on the furnace tube temperature. The temperature of the furnace tubes can be monitored using an infrared imager; if it exceeds the specified limit, the furnace must be shut down for maintenance.