This article explores the use of mechanical mixtures of a methanol synthesis catalyst (CuO/ZnO/Al 2 O 3) and acid catalysts (-Al 2 O 3) for enabling the one-step formation of dimethyl-ether from syngas. The study involved the determination of the optimal catalytic system composition and operating conditions in terms of reactant conversion and dimethylether yield. The catalysts mixture that exhibited the best performance consisted of 92.5% wt. of CuO/ZnO/Al 2 O 3 (7.5% wt. of -Al 2 O 3), when operated with an excess of H 2 (H 2 /CO > 1.5) and a small amount of CO 2 (4-6%) in the feed. The influence of temperature (250-270°C) was less marked, due to the influence of the equilibrium. The final purpose of the study of these properties is to develop one of the first kinetic models for the use of mechanical mixtures of commercial catalysts for this reaction. The experimental data were used to fit and validate a kinetic model based on four reactions: synthesis of methanol from CO, CO 2 , water gas shift reaction and methanol dehydration. At the studied reaction conditions, synthesis of methanol is kinetically relevant whereas water gas shift reaction and methanol dehydration are close to equilibrium. The inhibition caused by water was also accounted for in the kinetic model.

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Bio-oils obtained by pyrolysis of lignocellulose feedstocks must be upgraded to reduce the oxygen content, improving their quality as biofuels. Catalytic hydrotreatment has been proposed to reduce the oxygen content of biofuels and meet the standard requirements. Acetophenone is interesting as a model compound for the study of hydrodeoxygenation of pyrolysis bio-oils, which contain aromatic ketones. In this work, acetophenone gas-phase hydrodeoxygenation over precious metal (Pt, Pd, Ru, and Rh) supported catalysts has been studied in a fixed-bed reactor (space time, W/F = 0.75−1.0 kg cat s mol tot −1 ). The influence of the catalyst active phase and operating conditions (pressure of 0.5−1.5 MPa and temperature of 275− 375 °C) on the catalyst stability and activity and product distribution was studied. For the optimum pressure (1.0 MPa) and 275 and 375 °C, a reaction kinetic model based on the reaction scheme has been proposed and fitted to the experimental data obtained at different space velocities (W/F = 0−1.5 kg cat s mol tot −1 ).

The performance of a bench-scale monolithic reverse-flow reactor (RFR) for methane combustion has been experimentally studied in this work. The influence of the different operating parameters, such as total gas flow rate (2.5 Â 10(STP)), methane inlet concentration (1000-5500 ppm), and switching time (300-900 s) on the reactor performance (outlet conversion and stability), has been experimentally determined. The validation of a heterogeneous one-dimensional dynamic model for monolithic beds with the obtained experimental data allows the use of this model to simulate the behavior of industrial-scale reactors. In the second part of the work, a systematic comparison of particulate and monolithic RFRs is carried out through design curves. Reactor length for 99% outlet conversion and the corresponding pressure drop is determined for varying operating conditions (surface velocity and inlet methane concentration).