The hydrogenation refining filters for coker diesel and gasoline become clogged frequently

Reason: Excessive impurities in the raw materials. Recommendations for handling: 1. Raise the temperature of the raw materials to prevent low-olefin substances from sticking together and causing blockages; 2. Install an automatically switching filter for periodic cleaning.

Possible reasons are as follows: 1. High impurity content in the raw materials: Raw materials such as styrene tar and catalytic slurry used in the coking unit may contain many impurities, such as solid particles and precipitates; these impurities can easily clog the filters once they enter the hydrogenation unit. 2. Inappropriate operating conditions: The operating conditions of the hydrogenation unit may not be stable or suitable enough; for example, parameters such as temperature and pressure may not be set properly, which causes the feed material to condense, aggregate, and clog the filter as it passes through it. 3. Inadequate equipment maintenance: This may be due to the failure to clean or replace the filter elements in a timely manner, which leads to persistent blockages and subsequently affects the material heat exchange section of the high-pressure heat exchanger. To address these issues, it is recommended that you take the following measures: 1. Regularly check the impurity content in the raw materials and optimize the raw material processing procedures to reduce the amount of impurities that enter the hydrogenation unit. 2. Review and optimize the operating parameters of the hydrogenation unit to ensure stable operating conditions and prevent blockages. 3. Strengthen the maintenance management of equipment by regularly cleaning or replacing filter elements, as well as the feed heat exchange section of high-pressure heat exchangers, to prevent the continuous occurrence of blockage issues. In short, a comprehensive analysis and improvement of raw material handling, operating conditions, and equipment maintenance are necessary to address the issue of frequent clogging of the filters. .

I would like to ask you: is the operating condition of 0.9 MPa pressure and 45°C temperature suitable for feeding the raw materials into the unit?

Styrene tar and catalytic gasoline contain active olefins, which can self-polymerize into polymers at certain temperatures, thereby causing coking that blocks the heat exchangers.

What is the feed pressure under design conditions? What is the pressure difference when the filter is in operation? All need to be confirmed; simply adjusting the temperature is not enough – other conditions must also be taken into account

The distillation column upstream needs to be modified by adding sprays to reduce the carryover of coke powder. The filter needs to be upgraded to increase its capacity for processing raw materials, so as to generate a surplus flow. At the same time, special attention should be paid to the pressure difference before and after flushing the filter – whether it can return to its original level after flushing.

It is due to the combined effect of impurities and unsaturated olefins in the raw materials; it is necessary to use dispersant antiscalants to prevent the polymerization of olefins from causing sticking and aggregation. As a result, the impurities remain relatively loose and do not stick together easily, thereby significantly extending the filter replacement cycle. The efficiency of the system’s heat exchangers will also increase, and the operational life of the device will be extended

It is possible to consider adding antiscalant dispersants on the raw material side (the filter scale samples can be analyzed to select the appropriate product), thereby preventing polymerization and scaling within the system, extending the filter replacement cycle, and indirectly achieving energy savings and increased revenue.