Summary Post for Petroleum Refining Technology Exchange Area (27) – Root Cause Analysis

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I have compiled all the posts related to technical discussions on cause analysis within the oil refining technology exchange area, so as to make it easier for everyone to search, save time, find what they need, and assist others in solving problems! 1st floor: 1–100 2nd floor: 101–153 (Click the title directly to access the hyperlink) 1. What is the reason for the high liquid level in the reboiler condensate tank, preventing the condensate from being discharged? 2. Reasons for high steam loss 3. What are the reasons for catalyst deactivation during the normal operation of a catalytic unit? 4. Recently, the vibration level of the rear shaft of the smoke extractor has been high, varying from time to time, and the temperature of the lubricating oil is also a bit high. What could be the reasons? 5. Reasons for black spots on converter tubes 6. Analysis of coking causes 7. What are the reasons for blockages in the recycle hydrogen pipelines of hydrogenation units? 8. Causes of sodium poisoning in catalytic reforming catalysts and whether the catalysts can be regenerated? 9. Reasons for excessive temperature rise in hydrocracking processes. 10. Reasons for the bankruptcy of Panjin Ethylene (part of Huajin Group). 11. Why is gasoline not up to standard while thiol sulfur levels are acceptable? 12. What are the reasons for the storage tank becoming flattened? 13. What are the reasons for catalyst loss during shutdown for emergency repairs? 14. Reasons for cracks in the welds of the alkali solution line. 15. Reasons for negative pressure to occur in the coke tower during coke soaking! 16. What causes a high c3 content? ? 17. Causes of catalyst “bridging” and methods for dealing with it. 18. Recently, the outlet of the aftercooler in my unit has frozen; I would like to know what the cause might be. 19. Reasons for coking in coking steam turbines. 20. The level at the interface of the high-pressure tank in catalytic reforming pre-hydrogenation keeps rising and cannot be controlled; what is the reason? 21. The color of #3 industrial white oil is not good; I would like to know the reasons and solutions 22. Reasons for fluctuations in the exit temperature of the catalytic cracking riser. 23. What are the hazards of sodium in catalytic cracking? What are the reasons for its presence? 24. Why are the yields of dry gas and oil slurry increasing, while the yields of diesel, gasoline, and liquefied gas are decreasing? 25. Urgent: What are the main reasons for excessive diesel top pressure temperature? 26. Analysis of the deviation in operation and the causes of pressure drop in the RMC unit at Yanshan Petrochemical. 27. Reasons for unstable operation of the desorption tower in the catalytic cracking unit. 28. Reasons why the bottom drain line of the fixed-bed reactor used in gasoline refining often becomes blocked. 29. Reasons for insufficient temperature reduction in catalytic reforming. 30. Reasons for the sudden stoppage of the bottom pump in atmospheric and vacuum distillation units, along with solutions 31. During normal production, if the sulfur content in the reforming feed exceeds the specified limit, what are the possible causes? 32. What are the causes and hazards of oil carried in steam in a catalytic cracking unit? 33. What is the cause of frequent leaks at the superheated steam outlet of our plant’s coking furnace? 34. Why does the desulfurization tower in the coking process experience frequent flooding? 35. What are the reasons for seal leaks at the inlet and outlet of the crude oil pump? 36. What causes freezing in the non-condensable gas pipeline at the top of the stabilization tower in the absorption and stabilization section? 37. What are the reasons for coking in the large oil and gas line of the coke tower? 38. What is the cause of leaks in the top condenser? 39. The wing valves in the catalytic unit are severely worn, resulting in significant loss of catalyst – please analyze the reasons. 40. What is the cause of coking at the outlet connection of the large oil and gas line in the coke tower? 41. What are the reasons why hydrogenated diesel and crude gasoline fail to meet the standards? ? ? ? 42. Main causes of air compressor explosions 43. Diagrams of the two aileron valves; please analyze the reasons 44. Urgent: Please advise on the cause of leakage in the bottom reboiler of the deethanizer in the gas separation unit? 45. What are the causes of blockages in the dry gas lines during winter? 46. What is the reason for water being present in the refined dry gas? 47. What are the reasons for the wear and breakdown of the valve plates in the swirler vanes of the catalytic cracking settler? 48. What are the reasons for significant fluctuations in the reflux flow at the middle and lower sections of the absorption tower? 49. Reasons for the presence of numerous hot spots in the catalytic converters. 50. Reasons for the high carbon dioxide content in the dry gas desulfurization gas from the heavy catalyst unit? 51. Causes of oil in dry gas and methods for adjustment 52. Summary of operational difficulties in newly commissioned refineries due to design issues without any design changes 53. Causes of liquid in dry gas and methods for handling it 54. What are the reasons for poor heat exchange efficiency in oil coolers? 55. Hazards associated with high iron content in catalytic cracking catalysts and analysis of their causes 56. Investigation into the reasons for high pressure differences in reforming feed heat exchangers 57. Reasons for reduced aromatic content in reforming product oil 58. What are the causes of excessive pressure drop across the bed in hydrogenation reactors? 59. Reasons for crystallization and blockage in alkali liquor heaters 60. Reasons for large fluctuations in liquid level in catalytic distillation towers? 61. Cases of failures or even plant shutdowns caused by instrument measurement issues. 62. Reasons for the unsatisfactory corrosion resistance of diesel products. 63. Reasons for the presence of lead in gasoline. 64. What causes large radial temperature differences in hydrocracking reactors? 65. What are the reasons that can cause an incorrect liquid level reading in the high-pressure tank? 66. What are the causes of pump cavitation in liquefied gas pumps and how to address them? 67. What are the reasons for corrosion in the waste heat recovery system of heating furnaces? 68. Please discuss the reasons behind the formation of pellet coking, including the input materials and operating conditions. 69. Why is it difficult to maintain an accurate high-level control in hydrocracking units? 70. The piston rod of the new hydrogen generator in our company has broken; could everyone help analyze the reasons? 71. There is severe catalyst leakage in the regenerator – what are the main causes? . . . 72. Reasons for the increase in the acidity of circulating water. 73. Reasons for the increase in the circulation volume of the circulating hydrogen compressor. 74. Analysis of the reasons for yellow smoke emission from the regenerator in a catalytic cracking unit. 75. Reasons for high carbon content in the regenerated catalyst. 76. The valve position of the vent valve in the desulfurization flash tank is always around 100% open; please analyze the reasons. 77. Reasons for over-pressurization in the stripping tower. 78. What is the reason for the yellow color of catalytic liquefied gas? 79. Reasons for excessive sodium ions in the steam produced by the catalytic heat exchanger drum. 80. Why is the corrosive sulfur content in the hydrogenation and refining products often not up to standard? 81. Analysis of the reasons for poor performance of fiber membrane units. 82. Analysis of the reasons for \"surge\" in rich gas compressors. 83. Reasons for excessively high regeneration temperatures. 84. Why is a large amount of fine powder generated when the catalyst passes through the lift pipe and the settler? 85. Reasons for high losses in catalytic cracking. 86. What are the reasons for the high asphaltene content in coker wax oil? How to handle it? 87. If the purified water obtained after acid water treatment has a high ammonia nitrogen level and appears brown in color, what is the reason for this? 88. What is the reason for the high COD level in the wastewater from electrodialysis? 89. Severe scaling at the guide vanes of the three-spinning material legs; please analyze the reasons. 90. Why are there two solenoid valves on the quick-close valve at the outlet of the hydrogen feed pump in the PID diagram? 91. Please help analyze the causes of leakage in the compressed rich gas line at the compressor outlet and suggest solutions. 92. Analysis of the reasons for excessive sulfur content in the flue gas generated during catalyst regeneration. 93. Reasons for the formation of pellet coke in coking units and preventive measures. 94. Analysis of the reasons why the hydrogenated gasoline production process failed and corresponding solutions. 95. The three-spinning material legs caused the three-spinning system to stop functioning; experts are requested to analyze the reasons. 96. Reasons for the low rate of debt collection. 97. Is the outlet temperature of the main fan exceeding 240? What’s the reason? 98. Reasons for the low temperature at the top of the fractionation tower. 99. Discuss and analyze the reasons for the periodic and significant fluctuations in pressure in the catalytic stabilizer 100. Causes of filler damage in distillation vacuum towers