2 replies to this topic

[FrankSeipel]

We've experienced some gray color for the first few days following catalyst replacement of a hydrotreater at a used motor oil (VGO) re-refinery.  It eventually clears up, but catalyst vendor doesn't seem to be able to help.  We tried reducing bed temperatures.  Catalyst is pre-sulfided.  Any resources or thoughts are welcome.

[Root]

Their is possibility of Feed ex-changer tube leak. 

[FrankSeipel]

We do have a heat recovery exchanger wherein feed is preheated with product.  However, it comes up to temperature quickly, so that if it were leaking, problem would not go away as it does.  Problem persists for several days, while conditions (temperatures, pressures) of the exchanger are the same.