(Weekly Topic) What are the reasons for the high silicon content in the cracking gasoline from ethylene plants?
Thread Content
The second-stage hydrogenation reactor for gasoline in a certain ethylene plant had a short service life of just over a year. Preliminary analysis indicates that the high silicon content in the feed was responsible for catalyst deactivation. Please discuss the reasons for the high silicon content in cracked gasoline; has anyone encountered the same problem? How was it solved?
Is the pyrolysis gasoline derived from quenching? Is it the water added during quenching, or is the silicon content in the steam high?
The make-up water for the emergency cooling system of the ethylene plant is all recycled water, and no issues have been found with the water quality. No leaks were found in the cooling water coolers either; the water used for washing in the caustic scrubber comes from the wastewater discharged from the cracking furnace drum, but this is the case as well in ethylene plants.
The feed has a high silicon content; what form is the silicon in? Analyze the raw materials.
The cracked gasoline from the bottom of the butane removal tower is exchanged for heat with circulating water before being sent out, and similarly, the gasoline from the compressed low-pressure distillation tower also needs to be exchanged for heat with circulating water before being dispatched. Is it possible that there is an internal leak in the heat exchangers?
1. The crude pyrolysis gasoline produced by the ethylene plant mainly comes from three sources: the gasoline from the quench water tower, the gasoline from between the stages of the pyrolysis gas compressor, and the gasoline from the butane removal tower. It is recommended to take samples from each of these sources and analyze their silicon content to determine whether it is within normal ranges, before proceeding with further investigations. 2. If all three gasoline streams are normal, it is recommended to check whether the CW heat exchanger involved in heat exchange with them has internal leakage. 3. Another thing to consider is whether there are any issues with your catalyst and ceramic balls; one of the main components of ceramic balls is silicon dioxide.
I’ve heard of arsenic poisoning from the hydrogenation of pyrolysis gasoline, but I’ve never heard of silicon poisoning; try adding more CHP and see
Reply to 7# shjszdp: Arsenic poisoning mainly affects Stage 1 of the catalyst; it doesn’t have much impact on Stage 2, right? Moreover, excessive injection of peroxides not only fails to improve the arsenic removal effect but also easily causes polymerization hazards.
Instrument for detecting manganese, iron, silicon, and lead in gasoline: http://www.hi1718.com/company/331265/products/201633102927481.html Manufacturer, a listed company in the field of analytical instruments.