Abstract:

Since the 460 kt/a ethylene plant at PetroChina Lanzhou Petrochemical Company was started up after its overhaul in 2016, the activity of catalysts in the first stage of acetylene hydrogenation reactor has decreased significantly. Based on the statistical analysis of the operation data of the plant in this maintenance cycle, it was found that the coking on catalyst surface caused by temperature runaway and the formation of a large amount of green oil were the main reasons for the decrease in activity of acetylene hydrogenation catalyst. Compared with the previous cycle, the higher contents of acetylene and MAPD and the more C₄ components and potential heavy metal in the feed also accelerated the deactivation of catalysts. According to the actual situations, some suggestions for optimizing the operation of the plant were put forward.

Key words: C₂ , hydrogenation, catalyst, deactivation, optimal operation