ACCELERATED DEACTIVATION OF HYDROTREATING CATALYSTS - COMPARISON TO LONG-TERM DEACTIVATION IN A COMMERCIAL PLANT

Accelerated deactivation tests of a laboratory prepared Co-Mo/Al2O3 ca talyst were performed using three kinds of petroleum feedstocks. A hig h reaction temperature employed in the accelerated aging resulted in l arge amounts of carbonaceous deposition with high aromaticity, which w ere found to be the major deactivation cause. However, the effect of c arbonaceous deposition during accelerated deactivation tests might hav e been overestimated compared with that during practical hydrotreating , When the catalysts were aged in a H2S/H-2 Stream without petroleum u nder the same reaction conditions, the crystal growth of MoS2 layered structures was significant, but this rather resulted in an increase of both k (HDS) and k (HY). It was also suggested that the crystal growt h during a commercial hydrotreating run was unlikely to be the major c ause of catalyst deactivation. (C) 1998 Elsevier Science B.V. All righ ts reserved.