Modeling open-flow steam reforming of methanol over Cu/ZnO/Al2O3 catalyst in an axisymmetric reactor for hydrogen production

This paper describes a CFD study of the steam-reforming process (SRP) of methanol in a short pseudo-contact time reactor of fixed bed type, in axi-symmetric conditions. The SRP is important sake for hydrogen production, and the design /scale-up/control of the industrial processes in the future are supported by a reliable knowledge and prediction of the catalytic reaction. The difficulty of determining the reaction scheme and the associated constants is well-known, due to the necessity of identifying the reaction kinetics in purely chemical regime, meaning with a perfect homogeneity and flow independence. Practically these ideal conditions, albeit assumed, are not fulfilled so that the intrinsic chemical kinetics is not reached. For the case of SRP, we have attempted here to validate the Peppley’s model by a numerical modelling reproducing exactly the local conditions in the experimental duct, accounting for gradients in the cross section. The numerical results show the same trends than the experimental one, but with a slight shift of 20% as a consequence of the reactor heterogeneity. This result seems acceptable to validate the use of the Peepley’s model for further studies in other types of complex flow reactors

Modeling Open-Flow Steam Reforming of Methanol over Cu/ZnO/Al2O3 Catalyst in an Axisymmetric Reactor

This paper describes a CFD study of the steam-reforming process (SRP) of methanol in a short pseudo-contact time reactor of fixed bed type, in axi-symmetric conditions. The SRP is important sake for hydrogen production, and the design /scale-up/control of the industrial processes in the future are supported by a reliable knowledge and prediction of the catalytic reaction. The difficulty of determining the reaction scheme and the associated constants is well-known, due to the necessity of identifying the reaction kinetics in purely chemical regime, meaning with a perfect homogeneity and flow independence. Practically these ideal conditions, albeit assumed, are not fulfilled so that the intrinsic chemical kinetics is not reached. For the case of SRP, we have attempted here to validate the Peppley\u27s model by a numerical modelling reproducing exactly the local conditions in the experimental duct, accounting for gradients in the cross section. The numerical results show the same trends than the experimental one, but with a slight shift of 20% as a consequence of the reactor heterogeneity. This result seems acceptable to validate the use of the Peepley\u27s model for further studies in other types of complex flow reactors

Assessment of factors associated with community-onset Extended Spectrum Beta-Lactamase producing Escherichia coli urinary tract infections in France

Importance. Extended Spectrum Beta-Lactamase producing Escherichia coli is considered as a leading pathogen contributing to the global burden of antimicrobial resistance. Objective. The objective of this study was to better understand factors associated with the heterogeneity of community-onset ESBL-E. coli urinary tract infections (UTI) across France. Design. Cross-sectional study. Setting. 59 administrative departments of metropolitan France. Participants. This cross-sectional study performed in 2021 was based on data collected by the French nationwide network of clinical laboratories (PRIMO). E. coli strains isolated from community urine samples from January 1 to December 31 2019 for 59 administrative departments of metropolitan France were included. Main measure. Using quasi-Poisson regression models, we assessed the associations between several ecological factors available on government and administration websites for years 2010 to 2020 (demographic population structure, living conditions, baseline health-care services, antibiotic consumptions, economic indicators, animal farming density and environmental characteristics) and the number of ESBL producing strains among E.coli isolated from urine samples of individuals with community-acquired UTI in 2019. Results. Among 444,281 E. coli isolates from urine samples tested in 1,013 laboratories, the mean ESBL-E. coli prevalence was 3%. In an adjusted model, the number of community onset ESBL-E. coli UTI in each department was significantly (p <0.05) and positively associated with the percentage of children <5 year-old, overcrowded households, consumption of fluoroquinolones and tetracyclines (DDJ / 1000 inhabitants), and the poultry density. The social disadvantage index and the proportion of water surface were negatively associated with a higher number of community-onset ESBL-E. coli UTI. Conclusions. In this cross-sectional study, we confirmed the impact of fluoroquinolone usage and poultry density on the epidemiology of community-onset ESBL-E. coli UTI. Strategies to mitigate ESBL in the community should address the role played by tetracycline, overcrowded households and preschool children

Turbulent Liquid-Liquid Dispersion in Sulzer SMX Mixer

This paper presents an experimental study of pressure drop of single-phase flow and liquid−liquid dispersion through a Sulzer SMX mixer in the turbulent flow regime. Emulsification experiments are performed with various numbers of mixing elements from 2 to 20 and different flow rates ranging from 204 to 600 L/h. Pressure drop in single phase flow when Re is greater than 800 is modeled using a correlation based on the Blasius approach. The pressure drop is quantified at high Reynolds numbers for a liquid−liquid system. The droplet size distribution evolves along the mixer, and 10 mixing elements are required to reach break-up coalescence equilibrium in the case of emulsification experiments. Finally, assuming Kolmogorov’s theory of isotropic turbulence, a new correlation is established to predict the Sauter mean diameter in this mixing device as a function of the Reynolds and Weber numbers as well as the number of mixing elements

Prévention de la résistance aux antibiotiques : une démarche « Une seule santé »

Ce document présente les principaux résultats de surveillance de la consommation d'antibiotiques et de la résistance des bactéries aux antibiotiques pour l'année 2022 en santé humaine, animale et dans l'environnement en priorisant des indicateurs communs, ainsi que des actions mises en œuvre pour la prévention, le contrôle des infections et le bon usage des antibiotiques. Il cible les professionnels de santé humaine, animale et de l'environnement et est accessible à des professionnels non spécialistes de l'antibiorésistance

Prévention de la résistance aux antibiotiques : une démarche « Une seule santé »

Ce document présente les principaux résultats de surveillance de la consommation d'antibiotiques et de la résistance des bactéries aux antibiotiques pour l'année 2021 en santé humaine, animale et dans l'environnement en priorisant des indicateurs communs, ainsi que des actions mises en oeuvre pour la prévention, le contrôle des infections et le bon usage des antibiotiques. Il cible les professionnels de santé humaine, animale et de l'environnement et est accessible à des professionnels non spécialistes de l'antibiorésistance. L'année 2021, encore marquée par l'épidémie de COVID-19, révèle un maintien global des progrès en termes de consommation d'antibiotiques et de résistance aux antibiotiques par rapport à 2019 mais aussi des points de vigilance concernant les prescriptions d'antibiotiques, notamment chez les plus jeunes en santé humaine ainsi que la résistance aux antibiotiques tant en santé humaine qu'en santé animale. Dans le domaine de l'environnement, les travaux se poursuivent pour identifier les indicateurs les plus pertinents et standardiser les méthodes de recueil et d'analyse de la présence d'antibiotiques et de marqueurs de résistance dans les milieux. Concernant la prévention de l'antibiorésistance, le document décrit le panel d'outils à la disposition des professionnels en santé humaine pour la prévention des infections et le bon usage des antibiotiques