Monitoring

Monitoring at this stage confirms that the unit reached the intended condition and detects early signs of a problem while corrective action is still cheap.

The parameters are unit-specific but generally include reactor temperature profile, weighted average bed temperature, hydrogen partial pressure, recycle gas composition, pressure drop and the routine product analysis schedule. Comparing them against the basis the unit was commissioned on, rather than against the previous cycle alone, is what turns readings into a diagnosis.

Monitoring also has a logistics dimension: if the catalyst will reach a temperature or pressure drop limit sooner than planned, the earlier that is known, the more options exist — feed slate, operating target, an earlier regeneration, or rescheduling the next changeout.