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[Display omitted] • Combined CO 2 –H 2 O reforming of model biogas (66 % CH 4 + 34 % CO 2) was studied. • CO 2 /CH 4 reaction is inhibited in the presence of steam. • H 2 O and CO 2 follow a Temkin adsorption model. • H 2 O adsorption is favoured over CO 2 adsorption at temperatures relevant to reaction conditions. The combined dry-steam reforming (CDSR) of a model biogas (66 % CH 4 + 34 % CO 2) has been investigated under various feed compositions and reaction temperature conditions over a Ni-Rh/MgAl 2 O 4 catalyst, with the objective to convert the excess of methane (compared to CO 2) by steam reforming (SR). Methane, however, appeared to react preferentially with H 2 O rather than with CO 2 , leading to an inhibition of the dry reforming (DR) reaction in the presence of steam. CO 2 and H 2 O adsorption and co-adsorption studies revealed that H 2 O was always adsorbed in much higher amounts than CO 2 on the catalyst surface. A Temkin adsorption model applied to temperature-programmed adsorption experiments (TPAE) showed that two different strongly adsorbed CO 2 and H 2 O species were present on the catalyst surface at moderate temperature, but only one of each remained adsorbed at temperatures relevant to the reaction conditions (600−800 °C). H 2 O was also shown to displace CO 2 from the catalyst surface, confirming that they compete, at least partially, for the same adsorption sites. At high temperature, the surface coverage by the most strongly adsorbed H 2 O species was predominant. These results should contribute to the development of efficient catalytic processes for biogas valorization to produce syngas and hydrogen from renewable sources. [ABSTRACT FROM AUTHOR]

[Display omitted] • Review on the role of catalysis in woody bio-liquid valorization via fast pyrolysis. • Review on conversion through impregnated biomass, catalytic pyrolysis, catalytic conversion of vapors. • Review on cracking, reforming and various co-processing methods using bio-liquids. • Catalysis becomes increasingly important in many upgrading processes of bio-liquids. The objective of this review article is to focus on the role of catalysis in the various pathways involved in the value chain of fast pyrolysis liquids produced from wood. During the last 15 years, IRCELYON has been involved in many of these routes. This article is mainly focused on the role of catalysts in bio-liquid conversion and co-processing with petroleum feedstocks. We provide relevant references for each pathway and focus on the specific contributions of IRCELYON and on the most recent studies, not covered by previous reviews. [ABSTRACT FROM AUTHOR]

Hydrothermal liquefaction (HTL) of microalgae-derived feedstocks into a bio-binder was investigated in the absence or presence of a catalyst. The resulting products of HTL of Scenedesmus species (sp.) residues present rheological properties close to those of a petroleum-derived bitumen. The chemical composition of the biobinder was analysed by two-dimensional gas chromatography (GCxGC-MS), gel permeation chromatography (GPC), and negative and positive-ion laser desorption/ionization FT-ICR MS to provide a complementary analysis of the biobinder and understanding of the role of catalysts. A detailed description of the heavy nitrogen compounds contained in the biobitumen is given. [Display omitted] • Valorization of microalgae residues by catalytic HTL. • GPC, GCxGC-MS, FT-ICR MS and elemental analysis were carried out on the biocrudes. • FT-ICR MS provides description of the heavy nitrogen compounds in biocrudes. • Bio-binder similar to petroleum one assessed by rheological characterization. [ABSTRACT FROM AUTHOR]

On-board reforming of liquid fuels is attractive for fuel cell-powered auxiliary power units in vehicles. In this work, monometallic Ni/Al2O3/cordierite, Rh/Al2O3/cordierite and bimetallic Ni–Rh/Al2O3/cordierite monolithic catalysts were prepared, characterized and tested in ATR of isooctane for syngas production. Compared to monometallic formulations, the bimetallic Ni–Rh/Al2O3 catalyst was active for ATR at lower temperature and H2 production already reached the equilibrium composition in 400–550 °C temperature range. The Ni–Rh/Al2O3 catalyst exhibited stable performances for 140 h in ATR of isooctane at 700 °C, and was unaffected by oxidizing conditions at 700 °C. Thermoneutral reactions conditions at H2O/C = 2 were obtained with O/C = 0.66. Carbon deposition was marginal during ATR of isooctane and no carbons whiskers were detected. Post-reaction characterizations showed that the Ni particles were small enough to prevent filamentous carbon formation, while Rh also prevented carbon film deposition by improving the gasification of adsorbed C with steam. [ABSTRACT FROM AUTHOR]

[Display omitted] • The individual amounts of acid sites on metal oxides are measured using NH 3 adsorption equilibrium conditions. • The original method is based on the association of quantitative FTIR spectroscopy and volumetric measurements. • The method is applied to TiO 2 , WO 3 /TiO 2 and a V 2 O 5 /WO 3 /TiO 2 NH 3 -SCR catalyst. • The measurements permit the identification of the active acid site of V 2 O 5 /WO 3 /TiO 2 for the NH 3 -SCR reaction. The present study is dedicated to the development of an original method for the measurement of the individual amounts Q ASi of the acid sites AS i (acidity of Lewis and Brønsted) present on three TiO 2 based solids of increasing composition complexity: TiO 2 -P25, 6% WO 3 /TiO 2 -P25 and a sulfated 0.7 % V 2 O 5 /9% WO 3 /TiO 2 NH 3 -SCR catalyst. The method is based on quantitative characterizations of the NH 3 adsorption equilibrium (adsorption temperature T a and pressure P a) by the association of (a) the AEIR method providing the individual coverage θ ASi (T a , P a) of the adsorbed NH 3 species on the AS i sites and (b) the total amount (in μmol/g) of the adsorbed NH 3 species: QTNH 3 (T a , P a) by using a mass spectrometer. For a solid having n types of AS i sites, the Q ASi values are obtained from the numerical solution of linear equation systems (with at least n equations) obtained considering that QTNH 3 (T a , P a) is equal to the sum of the contribution of each adsorbed NH 3 species: Q ASi θ ASi (T a , P a).This imposes the measurement of at least n QTNH 3 (T a , P a) in a T a range preventing the contribution of parallel surface processes (i.e NH 3 oxidation). On TiO 2 -P25, n = 3 (two Lewis and one weak Brønsted acid sites) and the Q ASi amounts are obtained from three QTNH 3 (T a , P a) values. The others solids having two Lewis (L1 and L2) and two Brønsted (B1 and B2) acid sites impose a series of m measurements of QTNH 3 (T a , P a) with m>> n: the Q ASi are obtained by optimization between theoretical and experimental QTNH 3 (T a , P a) curves such as 109, 202, 70 and 130 μmol/g for Q L2 , Q L1, Q B2 and Q B1 respectively of 0.7 % V 2 O 5 /9% WO 3 /TiO 2. It is shown that these four amounts of sites permit to conclude that the L2 Lewis acid site is the one forming the pivotal NH 3ads-L2 species of the reaction by using nitrogen mass balances between the amounts of adsorbed NH 3 species and the N 2 production in the presence of NO. [ABSTRACT FROM AUTHOR]

A new membrane preparation method based on mechanical pore-plugging of the supports with appropriate sized seeds followed by secondary zeolite growth by hydrothermal synthesis was optimized for the production of hydroxy-sodalite (hydroxy-SOD) membranes. A series of parameters were investigated during membrane production, including seed loading, presence of Teflon on the coarse side of the support, top-layer orientation in the autoclave, autoclave agitation, synthesis time and temperature, membrane post-synthesis treatment, and nature and pore size of the support (TiO 2 /SS, SS, Al 2 O 3 and ZrO 2 /TiO 2 ). Zeolite seeds and synthesized membranes were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and gas permeation. The gas permselective separation ability of these membranes was demonstrated from H 2 , N 2 , CO 2 and H 2 O permeation tests at temperature up to 250 °C. The membranes fabricated with the optimized parameters achieved H 2 O/N 2 , H 2 O/CO 2 , and H 2 O/H 2 ideal gas permselectivities of 5.1, 4.8 and 1.4 at 250 °C, while providing a high water permeance ( Π H2O of 1.26 × 10 −7 mol Pa −1 m −2 s −1 ) at the same temperature. [ABSTRACT FROM AUTHOR]

Highlights: [•] TiO2 doped with Nb or Mg synthesized by hydrolysis of metal alkoxides. [•] Mg–TiO2 is basic, pure TiO2 is amphoteric, Nb–TiO2 is acidic. [•] Pd–Cu/(Mg or Nb)–TiO2 active catalysts for NO3 − hydrogenation. [•] Activity moderately influenced by support acid–base properties. [•] NH4 + selectivity unaffected by support acid–base properties. [ABSTRACT FROM AUTHOR]

After extraction of high-added value components of Spirulina sp., the remaining residues can be valorized by hydrothermal liquefaction to produce an oily water insoluble viscous phase (biocrude) which is very similar to petroleum bitumen. This hydrophobic fraction is composed of various N-,O-containing cyclic compounds, fatty acids, amides, nitriles, alkenes and alkanes. In order to optimize the rheological properties of the biocrude, we studied the addition of different catalysts with various loadings: ZrO 2 or CeO 2 , or Ce(NO 3) 3.6H 2 O as well as the effect of residence time during HTL. The biocrude has been systematically characterized by GCxGC, GPC, elemental analyses and dynamic shear rheology and compared to a petroleum bitumen. The different catalysts tested had little influence on the composition of the HTL hydrophobic fraction in the chosen operating conditions. In contrast, increasing the reaction time (from 1 to 7 h) was found to promote condensation reactions, thereby increasing the average molecular weight of the biocrude, leading to a viscoelastic material very similar to a petroleum bitumen. 1. Valorization of microalgae residues by catalytic HTL 2. Various catalytic system were compared (homogeneous and heterogeneous) 3. GPC, GCxGC-MS, elemental analysis were carried out on the biocrude 4. Bio-binder similar to petroleum one assessed by rheological characterization 5. Bio-bitumen rheology is strongly affected by the time of HTL [ABSTRACT FROM AUTHOR]