Record an incident of blackening of the feedstock in the hydrogenation unit
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Once an overpressure condition occurred in an upstream unit (in the form of direct feed from a vacuum distillation unit), it led to an increase in the pressure difference across the reactor beds in the subsequent diesel hydrogenation unit by 0.02 Mpa, triggering a pressure difference alarm. After taking samples on-site, it was found that the oil had turned black; as a result, the unit was put into extended cycle mode with feeding stopped. Lower the reaction temperature to below 200°C; once the color of the raw material returns to normal and the test results are within the normal range, switch back to the normal production process. After the pressure difference stabilized, there were slight changes, but it remained at 0.02 Mpa. With no changes in reaction temperature or pressure, the product can meet the specified quality standards. Conclusion: Maintain good communication with upstream and downstream equipment, test the properties of raw materials in advance to avoid irreversible situations.
I have encountered similar situations that resulted in substandard products; I once suspected leakage inside the heat exchangers used for the raw materials and the products
Were the changes upstream not communicated to you in a timely manner?
Indeed, there isn’t any; the main concern on the upstream side is facing punishment from management
Indeed, it’s true that the more people say it’s not one’s responsibility, the more necessary it is to check
After this situation occurred, were there any signs on the raw material filter? (For example, the number of backwash cycles increases or the pressure difference increases).
Time passes so fast; the pressure difference increases in less than half an hour.
That’s the situation with fixed-bed reactors – one can only wait until the next time it’s time to turn them over and replace the catalyst