Catalytic slurry system

Find the reason for the high solid content in the slurry and fix it

There’s a problem with the oil and gas cyclone separator.

1. Are there any issues with the settler and cyclone separator? 2. Catalyst screening. 3. Check the reaction conditions to determine whether it is necessary to increase the amount of external slurry fed in.

There must be a problem with the oil and gas cyclone separator

The high solid content is likely due to a decrease in centrifugation efficiency. The reasons for low centrifugation efficiency include too high or too low linear velocity of the lift pipe (which can be adjusted by changing the feed volume and steam volume), high inlet concentration of the material (depending on the structure of the settler, with steam volume and the level of material in the settler being the main factors), wear and damage to the equipment itself, high content of fine catalyst particles (severe cracking of the catalyst, overly efficient oil slurry filters, or a high proportion of fine particles in the catalyst itself), as well as too low amount of oil slurry being discharged. As for how to solve this, depending on your actual situation, increase or decrease the pipeline flow rate, increase the amount of slurry discharged outside; if there is slurry being reprocessed, consider temporarily shutting down the slurry filter. If none of these methods work, try carrying out a emergency repair to see if the equipment is worn out

1. Check the temperature of the superheated steam, especially that of the stripping steam, the steam used for lifting, and the steam used for atomizing the feed. If these temperatures are low, it is easy to cause thermal degradation of the catalyst, resulting in an increase in catalyst fines and a rise in the solid content of the slurry. 2. Is the amount of water injected during the reaction too large, resulting in an excessively high linear velocity in the centrifuge, increased catalyst loss, and an elevated solid content in the slurry? 3. Check whether the fresh agent in the catalyst tank is damp; if it is, it can also cause thermal degradation of the catalyst and an increase in the solid content of the slurry. 4. If implementing the above measures does not work, then there may be a problem with the centrifuge. It could be that the flap valve of the centrifuge cannot be opened or closed properly. As a last resort, increasing or decreasing the reaction pressure significantly can resolve the issue; if that still doesn’t work, the only solution is to shut down the machine.

It is done in two steps: 1. First, address the issue of high solid content. 　　Solution: Increase the circulation volume of the slurry, raise the amount of slurry discharged outside, and increase the reprocessing of recycled oil. 2. Identify the reasons for the high solid content. 　　Analysis: The high solid content of the slurry is causing the catalyst to escape from the settler; the issue needs to be addressed at the reaction level: is there a problem with the fluidization in the settler? ； Is there a problem with the level indicator of the settler? ； Is the material leg unobstructed? ； Does the catalyst exhibit thermal degradation due to damage? ； Is the processing load deviating too much from the design? Either too low or too high an inlet linear velocity in the centrifuge can affect its efficiency, leading to increased catalyst loss.

The direct cause of the high solid content in the slurry system is the reduced centrifugal separation efficiency in the settler, while the underlying factor is the breakdown of the catalyst, which generates a large amount of fine powder. Furthermore, the fine particles of MIP units are slightly larger than those in conventional catalytic cracking, but most of them are fine particles smaller than 10 μm. Calculate the linear velocity at the centrifugal separation inlet. Given your current situation, the top priority is to increase the discharge volume of the slurry, add some raw materials, reduce the solid content in the slurry, and ensure safety

It is possible to analyze the size of the catalyst particles in the slurry in order to determine what is causing the problem

Regarding the solid content of the slurry: 1. First, consider the process you are using; for units that employ the MIP or MIP-CGP process, the solid content of the slurry is higher than that in conventional heavy catalyst systems； 2. Is the method used for analyzing the solid content in your slurry centrifugal sedimentation or combustion weighing? 3. What is the shape of the quick separator at the outlet of the lift pipe? VQS., coarse rotation, three-blade quick separation, or coarse rotation soft connection? 4. If the service life of the top rotor in your settler has reached 6 years, you can consider the reasons for the decline in efficiency ； 5. There may be issues with the fluidization of the bed material inside the settler; sometimes poor local fluidization can affect the material discharge through the downcomers, among other factors. For reference only!