EFFECTS OF MATERIAL CHARACTERISTICS ON PERFORMANCE OF HYDROCRACKING CATALYSTS

Hydrocracking is a refinery process used to convert heavy hydrocarbon fractions to lighter cuts with high added value. The products that usually range from heavy diesel to light naphtha involving middle distillate as targeted cut are obtained as a result of hydrocracking process of feed with higher molecular weights and lower hydrogen/carbon ratios. Hydrocracking reactions occur under high hydrogen partial pressures and temperatures in the presence of catalyst in order to remove impurities such as sulfur compounds and crack heavy hydrocarbon molecules to high added value lighter cuts. Hydrocracking catalysts are bifunctional in which metal function with hydrogenation consisting group VIB or group VIIIB is for removal of impurities and acidic support consisting amorphous oxides and/or crystalline zeolites to realize cracking function. In this study, the association between the performance test results obtained from laboratory scale reactor system and the material characteristics of the catalysts are viewed. Selectivity, hydrocracking and hydrogenation activities within the performance parameters of the catalysts are calculated based on the fraction ratios and feed-product properties. Furthermore, the effect of hydrotreating activity on hydrocracking activity is also highlighted. The surface area and pore size, crystallinity, chemical composition of the material and acidic properties are investigated within the scope of material characteristics of the catalysts by using BET, XRD, XRF, NH3-TPD techniques, respectively.