• Energy Research

AbstractThe hydrogenation of furfural to furfuryl alcohol was performed in the presence of a Co/SBA‐15 catalyst. High selectivity (96 %) at a conversion higher than 95 % is reported over this catalytic system. As the conversion of furfural to furfuryl alcohol occurs over metallic Co sites, the effect of reduction temperature, H2 pressure, and reaction temperature were studied. Optimum reaction conditions were: 150 °C, 1.5 h, 2.0 MPa of H2. The catalyst was recyclable, and furfuryl alcohol was recovered with a purity higher than 90 %. The effect of the solvent concentration was also studied. With a minimum of 50 wt % of solvent, the selectivity to furfuryl alcohol and the conversion of furfural remained high (both over 80 %). Likewise, the activity of the catalyst is maintained even in pure furfural, which confirms the real potential of the proposed catalytic system. This catalyst was also used in the hydrogenation of levulinic acid to produce γ‐valerolactone selectively.

Cet article fait suite à celui paru en 2016, « Biomasse : l'avenir de la chimie du carbone ? », et traite plus spécifique-ment des ressources en biomasse, des fonctions de la bioraffinerie primaire, des manières de vaincre la « récal-citrance » de la cellulose, d'applications de la lignine, de conversions chimiques des acides gras, des technologies microbiennes d'obtention des huiles et de la filière terpénique. Les éléments moteurs de développement des produits biosourcés et les grands défis de la filière sont également présentés. This article follows "Biomass: the future of carbon chemistry?" published in June-July 2016 issue, and deals more specifically with biomass resources, functions of the primary biorefinery, ways of overcoming the "recalcitrance" of cellulose, lignin applications, chemical conversions of fatty acids, microbial technologies for obtaining oils, and with the terpenes value chain. The driving forces for the development of bio-based products and the major challenges of the sector are also presented.

AbstractWe show that the coating of choline chloride on silica‐supported AlCl3 allows the dehydration of carbohydrates to successfully proceed in low boiling point organic solvents. The concept is based on the in situ formation of a deep eutectic liquid phase on the catalyst surface, thus facilitating the interaction between the solid catalyst and insoluble carbohydrate.

We propose a methodology based on Hidden Markov Models (HMMs) to model scanning activities monitored by a darknet. The HMMs of scanning activities are built on the basis of the number of scanned IP addresses within a time window and fitted using mixtures of Poisson distributions. Our methodology is applied on real data traces collected from a darknet and generated by two large scale scanners, ZMap and Shodan. We demonstrated that the built models are able to characterize their scanning activities.

AbstractSince their introduction in 2004, deep eutectic solvents (DESs) have attracted interest in different fields of chemistry. In the case of biomass, DESs are particularly interesting, not only because of their low cost and biodegradability, but also due to their unique property to interact with hydrogen‐bond donors such as renewably sourced polyols or carboxylic acids. Through selected examples, we report the contribution of DESs for the dissolution of biomass, the extraction/purification of bioderived chemicals, and the conversion of carbohydrates to furanic derivatives. In all examples, we discuss how the DES can impact the selectivity of a chemical process and the limitations associated with the use of DES. In particular, impact of the DES viscosity on extraction, the recovery and recycling of DES, and the stabilization of chemical intermediates in DES are among the key aspects that are discussed.