Questions regarding the feedstock for reformation pre-hydrogenation
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Regarding the issue with the feedstock for reformation pre-hydrogenation, our plant replaced the catalyst in the pre-hydrogenation unit on August 24, 2009; by early April, the sulfur content became unacceptable. The inlet temperature of the reactor is 280±3°C. What could be the cause of this?
Personally, I think it might be a catalyst issue; it’s been in use for a long time.
Check for internal leaks in the heat exchangers for reactant and product flow, as well as those in the heat exchangers for feed and product flow of the stripping tower.
According to the original poster, the temperature and pressure should be fine. It’s worth checking whether the sulfur content in the feed is too high; the analysis is simple. The issue of internal leakage in the two heat exchangers mentioned on floor 3 can also be easily diagnosed. In my opinion, the catalyst is likely the problem – a catalyst doesn’t fail this quickly, after all, it’s only been half a year.
Does internal leakage in the feed and product heat exchangers of the stripping tower affect the pre-hydrogenation reactor?
The reasons are: 1. Internal leakage in the heat exchangers for reactant and product flow, as well as those in the heat exchangers for feed and product flow in the stripping tower； 2. If the sulfur content in the feed is too high, the reaction temperature can be increased to 295°C to see the effect ； 3. If raising the temperature does not solve the problem, it is a catalyst issue; contact the catalyst manufacturer to discuss possible solutions ； 4. If the temperature at the bottom of the stripping tower is too low, resulting in poor stripping efficiency, it is necessary to consider raising this bottom temperature.
This post was last edited by fengdingwen on 2010-4-14 08:27. The pretreatment process in our plant’s reforming unit involves hydrogenation first, followed by stripping!
What is the sulfur content of straight-run oil approximately? Check for leaks in the heat exchangers for the feed and product of the stripping tower, check for leaks in the heat exchangers for the feed and product of the pre-hydrogenation reaction, and only then consider raising the temperature.
The sulfur content of straight-run oil is less than 1000 ppm
First, it is necessary to determine whether it is inorganic sulfur or organic sulfur; then check whether the heat exchanger is leaking and whether the raw materials are of poor quality, before considering operations to increase temperature and pressure. Don’t do something too blindly; be sure to analyze it thoroughly first.
If there’s no issue with the process, then the reactor and catalyst need to be checked! Is the catalyst loading satisfactory? Is there channeling, or is severe crushing during loading? Anyway, let’s check them one by one; first, verify whether the analysis results are reliable ； Check again to see if there are any issues with the operation ； Then check the device ； Finally, only the reactor and catalyst are left! !