15 research outputs found
Mono-, bi-, and tri-metallic Ni-based catalysts for the catalytic hydrotreatment of pyrolysis liquids
Catalytic hydrotreatment is a promising technology to convert pyrolysis liquids into intermediates with improved properties. Here, we report a catalyst screening study on the catalytic hydrotreatment of pyrolysis liquids using bi- and tri-metallic nickel-based catalysts in a batch autoclave (initial hydrogen pressure of 140 bar, 350 A degrees C, 4 h). The catalysts are characterized by a high nickel metal loading (41 to 57 wt%), promoted by Cu, Pd, Mo, and/or combination thereof, in a SiO2, SiO2-ZrO2, or SiO2-Al2O3 matrix. The hydrotreatment results were compared with a benchmark Ru/C catalyst. The results revealed that the monometallic Ni catalyst is the least active and that particularly the use of Mo as the promoter is favored when considering activity and product properties. For Mo promotion, a product oil with improved properties viz. the highest H/C molar ratio and the lowest coking tendency was obtained. A drawback when using Mo as the promoter is the relatively high methane yield, which is close to that for Ru/C. H-1, C-13-NMR, heteronuclear single quantum coherence (HSQC), and two-dimensional gas chromatography (GC x GC) of the product oils reveal that representative component classes of the sugar fraction of pyrolysis liquids like carbonyl compounds (aldehydes and ketones and carbohydrates) are converted to a large extent. The pyrolytic lignin fraction is less reactive, though some degree of hydrocracking is observed
Catalytic hydrodeoxygenation of pyrolysis oil over nickel-based catalysts under H2/CO2 atmosphere
Sustained activation of DNA damage response in irradiated apoptosis-resistant cells induces reversible senescence associated with mTOR downregulation and expression of stem cell markers
Hydrodeoxygenation of phenolic model compounds over zirconia supported Ir and Ni-catalysts
Green catalytic valorization of hardwood biomass into valuable chemicals with the use of solid catalysts
Results of the study on green valorization of hardwood biomass into
valuable chemicals with the use of solid catalysts were described. The heterogeneous
catalytic processes of hemicelluloses and cellulose hydrolysis, wood oxidative
fractionation and lignin depolymerization in supercritical spirits are suggested
to employ for the green biorefinery of hardwood to xylose, pure cellulose, glucose,
alcohols and liquid hydrocarbons