Questions about the catalytic device
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I’m new to catalytic devices and have many questions; I hope the experienced folks here can help me out a lot. Let us outsiders learn from you*. Today’s main issues are: 1. Our reactor is a dual lift-column reactor. I would like to know whether the material at the top of the heavy oil fractionation tower can be directly extracted as light oil What are its flaws? What is the reason why it is necessary to use a light oil lift pipe? 2. Has anyone compared the light fuel oil obtained from the light oil fractionator with that obtained from the heavy oil fractionator? Which one has better quality? 3. What is the typical solid content level in the slurry? What should be the bottom temperature of the heavy oil fractionation tower? 4. If the flue gas extractor fails and stops operating, the flue gas is routed through a bypass to the waste heat boiler. The backup fan is started; its flow rate is 100 tons per hour less than that of the main fan. For a refinery with a processing capacity of millions of tons, how much longer can it operate in this condition? Is there no problem? 5. After being compressed by the pressure compressor, does the rich gas still leave the compressor in a gaseous state? Does the liquid phase separated by compression need to be fed into the light oil recovery system? 6. I’ve heard many engineers say that there is a risk of spontaneous combustion of FeS at the top of the fractionation tower, in the settler, as well as in the units for absorption and stabilization as well as sulfur recovery. So, fire suppression steam must be supplied. I would like to ask the experts: if I have enough nitrogen to maintain positive pressure in these areas, then there should be no problem, right? 7. For the blind flange of the feed oil and gas to the distillation tower, we also use thermal disassembly. What I would like to know is whether it’s possible to remove the blind flange after the heating of the two devices is complete and the air has been driven out using steam Thinking more extremly, if I had enough nitrogen and didn’t have to worry about losses, could I use nitrogen to continuously blow through the distillation tower to prevent air from entering it? That way, there would be no need to use a blind flange 8. Is it normal for the treatment capacity of the acidic water stripping section to be twice the amount of acidic water generated by catalysis? Is this the design for everyone? Is the acidity in the acidic water treated in the acidic water stripping section 98% due to catalysis? 9. Also, how is everyone’s propylene yield compared to the design value? Our design aims for an acrylonitrile yield of 42% – I’m not sure if this figure is reliable 10. Can a backup fan be used to start the system at the beginning of operation, and then the main fan be started once the smoke exhaust fan is in use? After all, the power of the main fan motor is too high. But I’m not sure if it’s feasible? I hope everyone can help analyze it more.
I suggest you take a look at the catalytic cracking operation guide
\"Technical Q&A on Catalytic Cracking Units\" is also good; I recommend giving it a look.
Yes, the two books mentioned upstairs are both published by Sinopec Press: one is a green-covered \"Operation Guide\" priced at 50 yuan, and the other is a yellow-covered \"Technical Q&A\" priced at 40 yuan. It’s a great deal considering future personal development
Answer 1: Yes, it’s possible； Defect: There is still a small amount of (relatively) heavy oil that has not been cracked ； There is no particular reason to go through this secondary lift column; it is mainly done to increase the yield of light oil, with even a small portion of the components distilled from the light oil fractionator being used for reprocessing. 2. There’s no need for comparison – of course, the light fuel oil obtained from the light oil fractionation tower has better quality. Yet it can’t really be said to have excellent quality; rather, upon analysis, its constituent molecules have relatively lower molecular weights, with fewer large-sized components. 3. The bottom temperature of the heavy oil distillation tower is generally controlled at around 450 degrees; higher temperatures can lead to coking. 4. If the exhaust fan fails and stops operating, the feed oil cannot be supplied in a normal manner; instead, the feeding amount must be determined based on the size of the backup fans available in your facility ； If the smoke extractor malfunctions severely, production must be halted. 5. Leaves the compressor in a atomized state ； It does not enter the light oil recovery system, but rather the absorption and stabilization system. 6. Logically speaking, there should be no problem with supplying nitrogen, but are these locations suitable for nitrogen supply? 7. The large blind plate must be installed; that’s for sure. If, as you say, the blind flanges are removed, air will get into the distillation tower. If no blind flanges are used, then when heating the vessel, won’t the distillation tower also be heated? Is that acceptable? 8. Normal; this is the safety factor adopted in the design, intended to maximize sulfur recovery and reduce air pollution. Most of the acidic water resulting from sulfur recovery comes from catalytic processes, with other sources including gas separation and hydrogenation processes. As for the proportions involved, they depend on the design requirements, as different designs have different specifications. 9. The propylene recovery rate in the plant I built is also around 40%, but it cannot be achieved after the plant starts operating, so it’s not reliable. That is the recovery rate under ideal design conditions; in actual production, however, various factors come into play, preventing it from reaching the levels specified in the design. 10. Your idea is correct; it’s totally fine! I hope my classmates will offer their criticism and suggestions
Reading more of the \"Technical Guides\" and \"Operation Manuals\" will definitely be very beneficial. When I was watching, many people said that it’s better not to take books at face value but to consider things carefully.