Sulfidation of conversion catalyst

When a fresh catalyst is first exposed to process gas, the bed temperature rises rapidly; if not controlled properly, this can lead to an excessive rise in the catalyst bed temperature, thereby damaging the catalyst. The solution is to use a low concentration during the initial gas introduction in order to control the temperature rise of the bed.

Generally, catalysts that have been saturated before leaving the factory do not require further saturation, but those that have not undergone pre-saturation must be saturated. Control the concentration and air flow rate entering the converter; the temperature rise of the catalyst should be slow, as a too rapid temperature increase can cause significant damage to the catalyst. Generally, the temperature is controlled at a level slightly higher than the maximum allowable temperature for the process operation

Purpose: To prevent the new catalyst from having excessive activity, which could lead to poor control of gas concentration and cause the catalyst to overheat, resulting in its deactivation and reduced service life! Pre-saturation helps to achieve a stable thermal equilibrium in the catalyst layer of the converter. 1. The pre-saturation concentration is generally kept at around 3%-4% (as low as possible), with the aim of raising the ignition temperature of one stage of the catalyst to the required level. 2. The temperature at the inlet of stages following the first stage can be set higher than the ignition temperature; the outlet temperature of the first stage should not exceed 620°C. Once the reaction temperature in the first stage becomes more stable, the gas concentration can be increased slightly to continue the saturation process in the subsequent catalyst stages. 3. After saturation has been achieved in all stages, the gas concentration can be raised to the normal operating level. 4. When using new catalysts for saturation purposes, it is necessary to ensure good coordination among all relevant teams.