Gas solid contacting measurements in a turbulent fluidized bed by oxidation of carbon monoxide

The conversion rate of the mass transfer controlled oxidation of CO over a Pt/gamma-alumina catalyst (d(p) = 65 mu m) has been studied in a fluidized bed (internal diameter = 0.05 m) operated close to and in the turbulent fluid bed regime. The objectives were to investigate the gas-solids contacting efficiency to evaluate the conversion data in terms of overall mass transfer coefficients and define the apparent contact efficiency. At high superficial gas velocities, the concept of formation of particle agglomerates and voids is more realistic than the two-phase model considering discrete bubbles and a dense phase. The two-phase model is not useless but has hardly any relation with the real flow pattern in the turbulent regime

Catalytic Hydrotreatment of Biomass-Derived Fast Pyrolysis Liquids Using Ni and Cu-Based PRICAT Catalysts

Biomass-derived fast pyrolysis liquids (PLs) are not directly applicable as transportation fuels due to their high oxygen content and limited storage stability. Catalytic hydrotreatment is an efficient technology to convert such PLs to finished fuels or intermediates that can be used as a co-feed for existing oil refinery units. In this paper, we report catalyst screening studies for the mild hydrotreatment of PLs using commercially available Ni and Cu-based PRICAT catalysts at rather mild conditions (200 °C, initial 140 bar H2pressure) in a batch setup for 4 h. Among all catalysts, PRICAT NI 62/15 showed the best performance for mild catalytic hydrotreatment in terms of product properties (highest H/C ratio and lowest TG residue). The best catalysts were also tested for deep hydrotreatment at more severe conditions (350 °C, initial 100 bar H2pressure). Here, the PRICAT NI catalysts showed better performance than the benchmark Picula Ni-Mo catalyst when considering oil yield and H/C ratio. Advantageously, the hydrogen consumption during deep hydrotreatment is also reduced, rationalized by a lower methanation activity

Public report on the marketability of the ABC-SALT middle distillates biofuels

Acknowledging the low TRL, this deliverable targets to analyze the ABC-Salt process with respect to its marketability. The process is investigated from a technical, economic, ecological and social perspectives: • The jet fuel market and current price development and production routes to produce sustainable aviation fuels are outlined. • Objectives of the process, the feedstock availability (and an according prospective product availability) and the target specifications of the final product are highlighted. • ABC-Salt products are benchmarked against thet targeted jet fuel specifications. • Process efficiencies, net production cost, global warming potential and the acceptability and acceptance are investigated. The results may aid to steer further researches beyond this projec

Valorization of Pyrolysis Liquids:Ozonation of the Pyrolytic Lignin Fraction and Model Components

Pyrolytic lignin is the collective name of the lignin-derived fraction of pyrolysis liquids. Conversion of this fraction to biobased chemicals is considered an attractive valorization route. Here we report experimental studies on the ozonation of a pine-derived pyrolytic lignin dissolved in methanol (33 wt %). Results show a high reactivity of ozone, and a molecular weight reduction of up to 40% was obtained under mild conditions (0 °C, atmospheric pressure) without the need for catalysts. Detailed analysis of the product mixtures (GC/MS-FID, HPLC, GPC, NMR) showed the presence of low molecular weight (di)acids and esters, along with larger highly oxygenated aliphatics. A reaction network is proposed including the heterolytic cleavage of aromatic rings, followed by secondary reactions. The observations were supported by experimental studies using representative pyrolytic lignin model compounds and a biosynthetic lignin oligomer, which aided further elucidation on the reactivity trends for different chemical functionalities. Accordingly, the presence of hydroxy and methoxy substituents on the aromatic rings is shown to be the main reason for the high reactivity of pyrolytic lignin upon ozone exposure

Novel Route to Produce Hydrocarbons from Woody Biomass Using Molten Salts

[Image: see text] The thermochemical decomposition of woody biomass has been widely identified as a promising route to produce renewable biofuels. More recently, the use of molten salts in combination with pyrolysis has gathered increased interest. The molten salts may act as a solvent, a heat transfer medium, and possibly also a catalyst. In this study, we report experimental studies on a process to convert woody biomass to a liquid hydrocarbon product with a very low oxygen content using molten salt pyrolysis (350–450 °C and atmospheric pressure) followed by subsequent catalytic conversions of the liquids obtained by pyrolysis. Pyrolysis of woody biomass in molten salt (ZnCl(2)/NaCl/KCl with a molar composition of 60:20:20) resulted in a liquid yield of 46 wt % at a temperature of 450 °C and a molten salt/biomass ratio of 10:1 (mass). The liquids are highly enriched in furfural (13 wt %) and acetic acid (14 wt %). To reduce complexity and experimental issues related to the production of sufficient amounts of pyrolysis oils for further catalytic upgrading, model studies were performed to convert both compounds to hydrocarbons using a three-step catalytic approach, viz., (i) ketonization of acetic acid to acetone, (ii) cross-aldol condensation between acetone and furfural to C(8)–C(13) products, followed by (iii) a two-stage catalytic hydrotreatment of the latter to liquid hydrocarbons. Ketonization of acetic acid to acetone was studied in a continuous setup over a ceria–zirconia-based catalyst at 250 °C. The catalyst showed no signs of deactivation over a period of 230 h while also achieving high selectivity toward acetone. Furfural was shown to have a negative effect on the catalyst performance, and as such, a separation step is required after pyrolysis to obtain an acetic-acid-enriched fraction. The cross-aldol condensation reaction between acetone and furfural was studied in a batch using a commercial Mg/Al hydrotalcite as the catalyst. Furfural was quantitatively converted with over 90% molar selectivity toward condensed products with a carbon number between C(8) and C(13). The two-stage hydrotreatment of the condensed product consisted of a stabilization step using a Ni-based Picula catalyst and a further deep hydrotreatment over a NiMo catalyst, in both batch setups. The final product with a residual 1.5 wt % O is rich in (cyclo)alkanes and aromatic hydrocarbons. The overall carbon yield for the four-step approach, from pinewood biomass to middle distillates, is 21%, assuming that separation of furfural and acetic acid after the pyrolysis step can be performed without losses

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