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The kinetics of methanol synthesis remains debatable for various reasons, such as the lack of scientifically conclusive agreement about reaction mechanisms. The focus of this paper is on the evaluation of the intrinsic kinetics of the methanol synthesis reaction based on CO2 hydrogenation and the associated reverse water–gas shift as overall reactions. The industrial methanol synthesis catalyst, Cu/ZnO/Al2O3/MgO, was used for performing the kinetic studies. An optimal kinetic model was assessed for its ability to predict the experimental data from differential to integral conditions, contrary to the typical fitting of only the integral conditions' data (common practice, as reported in the literature). The catalyst testing and kinetic evaluations were performed at various temperatures (210–260 °C) and pressures (40–77 bar), and for different stoichiometric numbers (0.9–1.9), H2/CO2 ratios (3.0–4.4) and carbon oxide ratios (0.9–1.0), in an isothermal fixed bed reactor, operated in a plug-flow mode. Experiments with CO in the feed were also generated and fitted. Different literature kinetic models with different assumptions on active sites, rate-determining steps, and hence, model formulations were fitted and compared. The original Seidel model appeared to fit the kinetic data very well, but it has twelve parameters. The modified model (MOD) we propose is derived from this Seidel model, but it has fewer (nine) parameters—it excludes CO hydrogenation, but it takes into consideration the morphological changes of active sites and CO adsorption. This MOD model, with three active sites, gave the best fit to all the data sets. [ABSTRACT FROM AUTHOR]

Understanding non-thermal plasma reactivity is a complicated task as many reactions take place due to a large energy spectrum. In this work, we used a well-defined photo-triggered non-filamentous discharge to study acetone decomposition in N2/O2 gas mixtures. The plasma reactor is associated to a compact chemical ionization FTICR mass spectrometer (BTrap) in order to identify and quantify in real-time acetone and by-products in the plasma. Presence of oxygen (1 to 5%) decreased notably acetone degradation. A tremendous change is observed in the by-products distribution concomitantly to a global decrease of their total concentration. While main products observed in oxygen-free gas mix are nitrile compounds, in oxygenated media they are replaced by formaldehyde, methanol and ketene. Methanol is maximum for 1% of O2 whereas formaldehyde and ketene concentration reach their maximum value at the highest oxygen concentration tested (5%). A number of nitrate, nitrite and isocyanate organic compounds (C1 and C2) are observed as well with HNO2, HNO3 and HNCO. [ABSTRACT FROM AUTHOR]

Understanding non-thermal plasma reactivity is a complicated task as many reactions take place due to a large energy spectrum. In this work, we used a well-defined photo-triggered non-filamentous discharge to study acetone decomposition in N 2 /O 2 gas mixtures. The plasma reactor is associated to a compact chemical ionization FTICR mass spectrometer (BTrap) in order to identify and quantify in real-time acetone and by-products in the plasma. Presence of oxygen (1 to 5%) decreased notably acetone degradation. A tremendous change is observed in the by-products distribution concomitantly to a global decrease of their total concentration. While main products observed in oxygen-free gas mix are nitrile compounds, in oxygenated media they are replaced by formaldehyde, methanol and ketene. Methanol is maximum for 1% of O 2 whereas formaldehyde and ketene concentration reach their maximum value at the highest oxygen concentration tested (5%). A number of nitrate, nitrite and isocyanate organic compounds (C1 and C2) are observed as well with HNO 2 , HNO 3 and HNCO.