Fluctuations in the material level in the reduction section of the reformation unit
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With the UOP technology, the material level display in the reduction section dropped from 60% to 30% within one minute. In the past, there were issues of catalyst buildup at the raw catalyst isolation valve; now it is suspected that the fluctuations in the material level are caused by the pipelines between the area below the raw catalyst isolation valve and the L valve assembly becoming empty, with catalyst flowing into these pipelines all at once and thus causing such fluctuations. However, upon closer consideration, the impact on the reduction section shouldn’t be so rapid, right? I was wondering if it’s the reduction section that is directly causing poor fluidization of the catalyst?
Describe clearly the problems you are facing! Is it periodic or occurs occasionally?
It’s not periodic; sometimes it happens once or twice a day, and other times three or four times a day
Could you explain it in more detail? 》
Several sets of devices exhibit this phenomenon, which is characterized by the formation of a cavity inside, or a \"wall-attached\" condition. The reasons include poor washing of the catalyst fine powder, clogging of the sieve in the first reactor, and high local linear velocity. I’d like to ask, is the fragrance content higher than the designed level? If conditions permit, one approach is to reduce the hydrogen flow rate in the recycle stream in order to lower the pressure drop in Reactor 1. Furthermore, lower the inlet temperature of the first reactor to allow hydrogen to be generated again in the second reactor. There was a previous post discussing a similar situation, and it was said that things improved after maintenance. At this year’s UOP annual meeting in Shaoxing, a local refinery also raised a similar issue. Indeed, the level of the material in that section dropped suddenly, both the level and the temperature. Or try reducing the processing volume; if it happens every day, you’ll get results after just one day of testing. Looking forward to your further reports.
Recently, the hydrogen flow rate for the reduction in both the first and second stages was reduced by 100 cubic meters each, and the temperature of the reduction gas was increased by 10 degrees. The material level continues to drop, but the rate of decline is smaller; it used to range from 60 to 30, while now it’s between 60 and 40... The amount of circulating hydrogen isn’t high, with a hydrogen-to-oil ratio of around 2.4–2.5
Recently, the aromatics potential of naphtha has been low, at 28, while the design value should be between 36 and 40
Can we exchange contact information and become friends?
I’ve checked it; there was indeed a high level of dust some time ago, in powder form. After adjusting the air volume used for dust removal, the dust level returned to normal, and it has remained normal ever since……
First, there is a large amount of fine powder, and then fluctuations in the level of the reduced material occur; this has happened before as well. During maintenance, it was found that the center tube of Reactor 1 was blocked, but the high amount of fine powder was due to damage in the internal mesh of the regenerator. After maintenance, operation resumed and the parity is normal. You reduced the fine powder through sieving, thereby gradually clearing the blocked areas.