Alternative Preparation of Improved NiMo-Alumina Deoxygenation Catalysts

Abstract

This investigation deals with NiMo-alumina hydrotreating catalysts effective in the deoxygenation of rapeseed oil. The main goal was to compare catalyst structure and their deoxygenation performance and to link these parameters to reveal important structural information regarding the catalyst's intended use. Catalysts were prepared from different precursors (nickel acetate tetrahydrate/molybdenyl acetylacetonate in ethanol and water vs. nickel nitrate hexahydrate/ammonium heptamolybdate tetrahydrate in water), which resulted in their contrasting structural arrangement. These changes were characterized by elemental composition determination, UV-Vis diffuse reflectance spectroscopy, temperature programmed reduction by hydrogen, nitrogen physisorption at 77 K, scanning and transmission electron microscopies, and deoxygenation of rapeseed oil. The critical aspect of high oxygen elimination was a homogeneous dispersion of NiO and MoO 3 phases on the support. It subsequently led to the effective transformation of the oxide form of a catalyst to its active sulfide form well-dispersed on the support. On the other hand, the formation of bulk MoO 3 resulted in the separate bulk phase and lower extent of sulfidation.

Catalytic Gasification and Reforming of Residual Biomass in a Bench Scale System with Low Cost Catalysts

“…In the case of NiMo/Al the X‐ray diffraction peaks of Ni (2θ=44.5° and 51.8°) [71] and Mo (2θ=40.5° and 50.7°) [72–74] species were not detected but small peaks of Ni at 2θ=44.5° and Mo at 2θ=40.5° were seen in the diffractogram of the fresh catalyst. γ‐Al 2 O 3 peaks of the fresh catalyst at 2θ=37.7°, 45.9° and 66.9° had a slightly higher intensity than those of the spent catalyst in which also the graphitic carbon peak was detected [70] .…”

“…Nevertheless the peaks of the fresh catalyst are more intense than those of the spent catalyst and a new small peak of graphitic carbon appears on the spent material. [69,70] In the case of NiMo/Al the X-ray diffraction peaks of Ni (2θ = 44.5°and 51.8°) [71] and Mo (2θ = 40.5°and 50.7°) [72][73][74] species were not detected but small peaks of Ni at 2θ = 44.5°and Mo at 2θ = 40.5°were seen in the diffractogram of the fresh catalyst. γ-Al 2 O 3 peaks of the fresh catalyst at 2θ = 37.7°, 45.9°and 66.9°h ad a slightly higher intensity than those of the spent catalyst in which also the graphitic carbon peak was detected.…”

Recent Advances of Triglyceride Catalytic Pyrolysis via Heterogenous Dolomite Catalyst for Upgrading Biofuel Quality: A Review

“…Transition metals such as nickel- and cobalt-based catalysts have been proven to be very active and have widely been used for hydro processing in the heavy oil industry, as well as in the production of liquid biofuel [ 77 , 78 ]. Previous research showed that an alumina supported NiMo catalyst could be used to convert vegetable oil to alkanes and alkylbenzene [ 79 ]. In addition to that, alumina supported NiMo and CoMo catalysts are applicable as an effective deoxygenation catalyst to produce hydrocarbon products [ 80 ].…”