Crushing of hydrogenation catalysts
Thread Content
Has anyone here encountered the issue of hydrogenation refining catalysts breaking down? What was the ultimate cause identified? The catalysts in beds 1 and 2 (out of a total of 3) for the wax oil hydrogenation process are severely damaged; the reactor pressure rise reached 12 bar, whereas it was only 5 bar at the start of operation. During operation, there were no signs of water contamination in the feed material, overheating, or emergency pressure relief. Seeking advice!
We use foreign catalysts, and there has been no instance of them breaking; the pressure drop is also low. You reached a pressure difference of 5 kilograms right at the beginning of operation, which is already quite high. Was there a problem during the catalyst loading process? During the later stages of operation, was there an increase in pressure difference and catalyst breakdown, as well as multiple occurrences of temperature and pressure changes? Based on your description, I tend to agree with the view that the catalyst strength is insufficient.
Were there any issues during charging, or is the space velocity too high?
Due to the dense packing we use, along with the internal components, the initial pressure drop is relatively high. The temperature increases and decreases are part of the normal start-up and shutdown procedures; there was only one instance of a safety valve malfunctioning, which caused 20 bar of pressure to be released in 4 minutes. Regarding the catalyst, we have some samples on hand, which are stored under vacuum; we’ll test their strength to see
Loading should be fine; there was constant supervision during the loading process, and the falling height of the catalyst was not excessive. After operation began, the radial temperature difference remained within 2°C
When blending wax oil, the pressure drop is 0.28 MPa, while it is 0.17 MPa for pure diesel; dense-phase packing is also used, with a total of 5 beds. In another hydrogenation setup previously, the same catalyst was used, and very little of the catalyst broke during replacement. If it’s a problem with the catalyst itself, then it’s hard to tell; I don’t know much about this.