No abstract

In this work, the composition, structural and morphological features, and particle size of the active phase of the catalyst (MoS2), synthesized in-situ during the heavy oil hydroconversion performed in continuous flow reactor on lab-scale pilot flow unit at T = 450 °C, P = 6.0–9.0 MPa, V = 1.0 h−1, H2/feed = 1000 nL/L, catalyst concentration C (Mo) = 0.01–0.08%wt have been studied. It has been shown that MoS2 formed during hydroconversion is represented by nanosized particles stabilized by polycondensation products as a result of strong adsorption and aggregation with the components of the hydroconversion reaction medium. The influence of morphological characteristics of catalyst nanoparticles on the feed conversion, the yield of gaseous and liquid products, and the quality of distillate fractions, as well as the yield of polycondensation products, have been studied. It has been established that an increase in MoS2 active site dispersion, both due to a decreased plate length and lower stacking numbers in MoS2 cluster, enhances hydroconversion effectivity, particularly, in suppressing polycondensation reactions.

This study represents the results of ex-situ synthesis and research of the properties of concentrated suspensions with new catalysts for petroleum residue hydro-conversion. Suspensions were prepared and stabilized in a petroleum residue medium through reverse emulsions containing water-soluble Mo-precursor and S-containing agents (elemental sulfur, thiocarbamide) in the absence of a solid carrier. The resulting ex-situ catalyst dispersions had Mo content of 6-10 wt % and contained nanosized and submicron catalyst particles stabilized in a petroleum residue medium. The effects of S-containing agents on the properties of catalytic particles (sulfidation level, dispersity, structural and morphological features) were studied. The synthesis conditions for the optimal ex-situ catalyst providing the lowest coke yield (0.2 wt %) and the highest conversion (55.5 wt %) during petroleum residue hydro-conversion in a single pass mode have been determined.