Publikace (přehled)

Generally, the commercial catalysts for hydrotreatment in refineries are supported sulfide transition-metal-based catalysts. However, the co-processing of vegetable oils reduces their hydrodesulfurization (HDS) efficiency by leaching sulfur from the active sites of the catalyst. The present work reports the use of six sulfur-free MoCx and MoNx catalysts (supporter with Al2O3, TiO2 or ZrO2) for the hydrotreatment of atmospheric gasoil (AGO) and co-processing of rapeseed oil (RSO). The screening tests were carried out in a fixed bed reactor at industrial operating conditions (330-350 oC, 5.5 MPa, WHSV = 1-2 h-1, AGO/RSO = 100/0, 95/5, 90/10 and 75/25 %wt.). Higher reaction temperatures and lower fed rates had a positive effect on catalyst activity and product quality. In the case of co-processing, hydrodeoxygenation reaction mechanism was found to be dominant, producing n-C16 and n-C18 n-alkanes at all AGO/RSO ratios used. Overall, our results suggest that alumina supported catalysts are the most promising materials, exhibiting a combination of excellent stability, high activity and no negative effects on HDS efficiency during AGO/RSO co-processing.