Hydrorefining reactor
Thread Content
For the newly installed hydrogenation refining reaction catalyst, after operation the temperature is high at the upper part of the reactor and low at the lower part – what causes this? Moreover, the radial temperature distribution is extremely uneven. The pressure difference across the reactor bed does not change much; could this be due to bed collapse or to uneven activity resulting from inadequate sulfidization of the catalyst during pre-sulfidization? Instrumentation problems have been largely ruled out. The temperature at the upper part is around 370 degrees, while it is around 340–350 degrees at the lower part
What is your raw material ratio?
Is the catalyst in the upper layer a catalyst for other reactions?
If the temperature distribution is uneven, that’s not good; it’s very likely a problem that occurred during filling
The loading is uneven, and the feed rate is too fast; the adsorption heat of the catalyst has not been properly managed
It could be a problem with the raw materials – low levels of sulfur and nitrogen, metals, and unsaturates – in which case the upper-layer reaction can handle it； Or there was a problem with the catalyst filling.
Is it because the grading has resulted in several layers, with each layer having a different catalyst activity? In the worst case, it could be due to uneven packing, bridge formation, or channeling.
The extreme radial temperature unevenness is likely caused by the way the catalyst is loaded, or it may be due to partial blockage of the catalyst support plates. Slight radial temperature differences can result from too low a feeding rate for an extended period of time; in our case, the radial temperature differences are caused by the blockage of one of the support plates in the catalyst bed
The temperature at the highest point isn’t very indicative; what matters is the overall temperature difference between the two beds. Generally, the temperature of the upper bed increases while that of the lower bed decreases. It does not happen that the upper bed has a higher temperature than the lower bed, unless cold hydrogen is being supplied