Synthesis of renewable hydrocarbons from vegetable oil feedstock by hydrotreatment over selective sulfur-free SiO2-Al2O3 supported monometallic Pd, Pt, Ru, Ni, Mo and bimetallic NiMo catalysts

Screening tests of commercial and prepared monometallic Ni, Mo, Pd, Pt, Ru and bimetallic NiMo catalysts synthesized by four different impregnation methods were performed to evaluate their selectivity and performance on hydrocarbon production from vegetable oil feedstock with high free fatty acid (FFA) content (similar to 50%) by solvent-free hydrotreatment (HT). Catalysts were characterized by N2 sorption analysis, XRF, XRD, FE-SEM and TEM. Composition of feedstock and liquid, gaseous products were analyzed by C, H, N, S elemental analysis, FT-IR, GC-FID, GC-MS and GC-TCD. Mo promoted Ni17Mo3DP synthesized using developed one-pot deposition-precipitation procedure exhibits great performance, selectivity to n-C18 and 6-7% higher hydrocarbon yield (similar to 87%) than elevated metal loading (>= 65%) commercial Ni65C and Ni66C catalysts achieved at relatively mild reaction temperature 320-340 degrees C and initial H-2 pressure 6-10 MPa. Completely different selectivity of highly active Ru, Ni and NiMo catalysts can be beneficial for wide molecular weight marketable renewable hydrocarbon production from fatty acid containing raw materials.

Automated summary

Screening tests were carried out on various monometallic and bimetallic catalysts synthesized by different impregnation methods to evaluate their performance and selectivity for hydrocarbon production from vegetable oil feedstock with high FFA content. Among them, the Mo-promoted Ni17Mo3DP catalyst exhibited great performance and selectivity, achieving a higher hydrocarbon yield and demonstrating potential for producing renewable hydrocarbons from fatty acid containing raw materials.