I have a few simple questions regarding catalytic reforming; I would appreciate it if experts could help answer them
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Why must the feed for catalytic reforming reactions be at 370°C? The hydrogen introduction process in our facility is as follows: boundary zone → activated carbon tank → molecular sieve tank → reaction system ； During the reduction process, molecular sieve must always be used ； During thermal hydrogen desulfurization, once the H2S concentration falls below 1 mg/kg, reduce each reaction inlet temperature by 300°C at a rate of (20–30)°C, and then remove the molecular sieve tank. Thus, a question arises: is there any temperature requirement for using molecular sieves? When asking colleagues, some said that at 1.2 MPa and 300°C, water in the gas vaporizes, and molecular sieves can effectively adsorb this water. But when starting up and introducing process hydrogen at room temperature through the molecular sieve, will it be effective? Or is it the activated carbon canister that plays a key role in absorbing any moisture present in the gas when hydrogen is introduced? If that’s the case, then why is the molecular sieve tank still included in the startup process? In short, is the molecular sieve tank usable at any temperature? The reaction feed analysis for this device shows: water content in ppm, n-alkanes in %, isomeric alkanes in %, olefins in %, cycloalkanes in %, and aromatics in %. The values are 27.7, 14.38, 5.93, not detected, and 78.92, 0.62 respectively. What are the requirements regarding chlorine injection for raw materials with this composition? Is chlorine being injected at 0.3 and 0.6 now? Is it reasonable? I always feel that two stages of chlorination aren’t necessary to such an extent. What is the essential difference between pre-debunking and post-debunking? Is it just energy consumption? For now, it’s just this one question; I hope all experts can point out any mistakes and provide answers! Thank you
At 1,370°C, the material neither reacts nor vaporizes, so it is used as the feed temperature. 2. We don’t have this, so we can’t answer you. 3. The chlorine dosage should be related to factors such as the catalyst’s activity, the octane rating of gasoline, and the aromatic hydrocarbon yield; in particular, there are specific requirements regarding the chlorine content in regenerated catalysts – for example, UOP specifies that the chlorine content in regenerated catalysts should be between 1.1% and 1.3%. It doesn’t have a particularly strong relationship with the reaction products. 4. The fourth question is probably about whether carbon hexa can be removed from hair removal oil. In my opinion: if the unit has an aromatic extraction system, then the C6 in the raw materials does not need to be removed; that’s how our unit operates ； If the unit does not have an aromatic extraction unit, then hexane should be removed, as national standards require that the benzene content in gasoline be below 1%. Personal opinion, for reference only
2. The main purpose of molecular sieves is dehydration; they are typically used at room temperature, and their use is not necessary when the water content in the system is low； After being in use for a period of time, the molecular sieve needs to be regenerated and dehydrated; once regeneration is complete, it is brought back to room temperature for future use.
I’ve learned it, thank you all, experts.