Please tell me why the solid content of prawn oil slurry always fluctuates between 4.0-6.0?
Thread Content
Our device is for catalytic cracking of wax oil. The solid content of the oil slurry has always fluctuated between 3.5-6.0 for a month. Our control index is less than 2.0g/L. We have no effect on the solid content of the oil slurry by adjusting the steam consumption, the processing capacity of the device and the linear speed of the cyclone. The wind used does not carry water, but the superheat degree of the steam is not high due to the heat exchange effect of the waste heat furnace. The catalyst used has also been changed, and the effect of changing from Lanzhou agent to Changling agent is not obvious. Now we only have to consider the issue of the cyclone. Could you please help me analyze the possible causes? Will the current solid content cause a lot of wear and tear on pipelines and equipment? :) :)
Some personal opinions: First, it is most likely a problem with cyclone separation. Analyze whether the cyclone equipment is normal and healthy, do a catalyst particle size analysis, and calculate whether the cyclone efficiency matches the design. Second, the high solid content of the oil slurry will increase the coking tendency of the oil slurry system and affect the long-term operation of the oil slurry system. If your installation has oil slurry refining, can you consider reducing the amount of refining and increasing the amount of oil slurry thrown out? Thirdly, it is recommended to pay more attention to the pressure drop of the oil slurry system and adjust the amount of antiscalant injection in a timely manner. :lol :lol :lol :lol Thank you for your advice!
2 additional points: 1. Check whether the amount and temperature of steam injected into the regeneration system have changed, and whether the regeneration temperature is too high (calibrate the thermocouples in key parts) ； 2. Check whether the personnel doing the analysis and testing have changed. For the same analysis project, different people sometimes produce different results. For reference only.
Another point to note is that if the nozzle outlet linear speed is too high, exceeding 100m/s, it will have a certain effect on catalyst fragmentation. The main reason is that excessive steam in the cyclone and reactor can easily cause thermal collapse. There is another possibility related to the experimental method. Generally, centrifugal sedimentation is used to measure the solid content. If the centrifuge rotation speed is too low, it is easy to produce a high value of solid content. Ask the laboratory how much the centrifuge line speed is controlled.
1. Is it necessary to control the oil slurry solid content to 2g/L? Generally, it is not more than 10g/L under stable working conditions. 2. The coking of the oil slurry system is not necessarily affected by the solid content. High temperature has the greatest impact on the coking of the oil slurry system. It also depends on the viscosity change of the oil slurry. If the viscosity is too large, asphaltene-type scaling may occur, causing poor circulation of the oil slurry system. 3. Use the burning method to remove the ash in the oil slurry. The ash is the true manifestation of catalyst loss. 4. Is the oil slurry being thrown out or is it being refined? Is the external rejection amount + refining amount too small to concentrate the oil slurry? 5. Micrographs can be used to observe the form of the solid in the catalyst and oil slurry to see if it is caused by the broken catalyst? And the screening size of solids in the oil slurry can be analyzed to judge the efficiency of spinning.
The solid content control indicator in the operating procedures is less than 2.0g/L. However, in general operations, the solid content will be slightly higher than 2.0g/L. As long as it is not more than 10g/L, there should be no big problem. Our devices have been above 10 recently, even greater than 25.4. The solid content in production is sometimes high and sometimes low, so there shouldn’t be much problem with the cyclone. I think it should be considered from the actual operation and raw materials.