Catalyst loading issue
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These past two days, our reactor has been having its catalyst replaced. 1. What are the precautions to take when installing the catalyst axially and radially in the reactor?； 2. Are there any professionals in the field of catalysts? There is a step where alkali solution is used to wash away the scale; what is the principle behind this? What gets washed away? Why does it remain black after washing? Everyone is welcome to share their thoughts; I will keep an eye on this post regularly. There are still many things I don’t understand
1. Catalyst loading is divided into normal loading and dense-phase loading. Close-phase filling makes it easier to ensure uniform packing density. During normal filling, be sure to level the surface after filling to a certain height. 2. After the hydrogenation reaction system is cooled and depressurized, water vapor condenses; or when the equipment is opened for maintenance, its interior and pipelines come into contact with humid air. When iron/chromium sulfides react chemically with water and oxygen, sulfurous acid and polythionic acid are formed, thereby causing corrosion. For austenitic stainless steel equipment and pipelines that need to be disassembled for maintenance, as well as heating furnace tubes that cannot be maintained at temperatures above 149°C, they should be neutralized and rinsed using a solution of 1.5% to 2% sodium carbonate (Na2CO3) or sodium hydroxide (NaOH). After rinsing, it is essential to use chloride-free softened water or condensate for rinsing, in order to prevent residual alkali from remaining on the surface and causing alkali embrittlement, as well as from being carried into the catalyst at startup and affecting its activity.
What type of device or reactor is used, and what kind of catalyst is loaded into it? Different situations are different
Thank you for your guidance. We are working on a pre-hydrogenation reactor that has been restructured; the catalyst used is FH-40B, and the conventional packing method mentioned earlier is being applied. I’ve never heard of what dense-phase packing is – could you explain it in more detail?； I’m quite concerned about whether rinsing with alkaline solution – without the step of using softened water or condensate water for rinsing – could have an impact on pre-hydrogenation
Regardless of the type of device or reactor and the category of catalyst used, care must be taken during loading to ensure a homogeneous packing density in a dense-phase filling. During normal filling, be sure to level the surface after filling to a certain height.
The catalyst manufacturers have requirements regarding loading
Keep paying attention and learn from the seniors*