CNRS Integrated Transformations of Renewable Matter

Compiegne, France

CNRS Integrated Transformations of Renewable Matter

Compiegne, France
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Qiu X.,South China University of Technology | Len C.,CNRS Integrated Transformations of Renewable Matter | Luque R.,University of Cordoba, Spain | Li Y.,South China University of Technology
ChemSusChem | Year: 2014

A highly efficient, simple, and versatile transition-metal-free metal-organic framework catalytic system is proposed for the oxidative coupling of amines to imines. The catalytic protocol features high activities and selectivities to target products; compatibility with a variety of substrates, including aliphatic amines and secondary amines; and the possibility to efficiently and selectively promote amine cross-coupling reactions. A high stability and recyclability of the catalyst is also observed under the investigated conditions. Insights into the reaction mechanism indicate the formation of a superoxide species able to efficiently promote oxidative couplings. Neat couple! A metal-organic framework with open 2,2'-bipyridine sites offers a new, simple, and green protocol for the selective synthesis of imines from oxidative coupling of various amines under mild solvent-free conditions in the absence of transition metals. In addition, this catalyst is also capable of catalyzing the cross-coupling of two different amines to synthesize asymmetrical imines with unprecedented selectivity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Barba F.J.,University of Valencia | Grimi N.,CNRS Integrated Transformations of Renewable Matter | Vorobiev E.,CNRS Integrated Transformations of Renewable Matter
Food Engineering Reviews | Year: 2014

In recent decades, microalgae species have focused the attention of several research groups and food industry as they are a great source of nutritionally valuable compounds. The use of environmentally friendly technologies has led to researchers and food industry to develop new alternative processes that can extract nutritionally valuable compounds from different sources, including microalgae. This note describes the potential use of some non-conventional methods including sub- and supercritical fluid extraction, pulsed electric fields, high-voltage electric discharges, high-pressure homogenization, ultrasound- and microwave-assisted extraction, which involve cell disruption to recover nutritionally valuable compounds from microalgae and can help to comply with criteria of green chemistry concepts and sustainability. © 2014, Springer Science+Business Media New York.

Diallo A.-O.,INERIS | Diallo A.-O.,CNRS Integrated Transformations of Renewable Matter | Morgan A.B.,University of Dayton | Len C.,CNRS Integrated Transformations of Renewable Matter | Marlair G.,INERIS
Energy and Environmental Science | Year: 2013

The aim of the study is to provide advanced knowledge on the thermal and combustion hazard profiles of ionic liquids based on an original multiscale combined experimental approach. Experimental tools have been implemented and used to (a) obtain actual measurements of theoretical heats of combustion of imidazolium-based and phosphonium-based ionic liquids by use of a bomb calorimeter; (b) provide access to fundamental flammability properties of these chemicals through the use of Pyrolysis Combustion Flow Calorimeter; and (c) determine actual behaviour of ionic liquids in fire conditions, from learnings obtained by a series of combustion tests performed on 12 ionic liquids by use of the INERIS Fire Propagation Apparatus. Results so far confirm that the combustibility potential as well as the fire behaviour must be assessed on a case by case approach and is often dictated by the chemical structure of ionic liquids. The study also illustrates how the data obtained by our innovative procedure allow for consistent fire safety engineering studies serving the green use of ionic liquids in a contextual way. The work has opened a new perspective of collaborative work towards the development of a dedicated and pertinent methodology aiming at characterizing the comprehensive physicochemical hazard profiles of ionic liquids. © 2013 The Royal Society of Chemistry.

Khelfa A.,CNRS Integrated Transformations of Renewable Matter | Bensakhria A.,CNRS Integrated Transformations of Renewable Matter | Weber J.V.,University of Lorraine
Journal of Analytical and Applied Pyrolysis | Year: 2013

The effect of mineral addition on biomass thermal decomposition was investigated in slow pyrolysis conditions (10 °C min-1). The tests were carried out on the biomass components, their mixtures and real wood (birch wood), using thermogravimetric analyses (TGA) and pyrolysis coupled to mass spectrometry technique (Py-MS). The main criteria chosen to study the additivity of thermal behaviour were: the mass loss of the samples (C.R %), the temperature of the maximum mass loss (Tm) and the initial degradation temperature (Ti). Furthermore, to highlight the primary reactions of thermal behaviour of the studied samples, the chemical composition of emitted vapours was analysed and the influence of some mineral salts (MgCl2, NiCl2) on pyrolysis primary mechanisms was also investigated. Considering the large data sets collected (integrated MS intensities of 19 selected ions), principal component analysis (PCA) was used to provide a tool to simplify pyrolysis data interpretation. Considering mineral effects, it is possible to favour some primary mechanisms: dehydration (inducing to char formation); ring opening (with gas and light vapours formation) and depolymerisation (with sugars, pyrans and furans formation). MgCl2 catalyses inter (or intra) molecular dehydration. However, NiCl2 does not catalyse the mentioned primary reactions but appreciably modifies the emitted gas and vapours composition. With the help of the PCA calculations, the effect of metallic salts on xylan and ternary mixtures was evidenced. © 2013 Elsevier B.V. All rights reserved.

Herve G.,CNRS Integrated Transformations of Renewable Matter | Sartori G.,CNRS Integrated Transformations of Renewable Matter | Enderlin G.,CNRS Integrated Transformations of Renewable Matter | MacKenzie G.,University of Hull | Len C.,CNRS Integrated Transformations of Renewable Matter
RSC Advances | Year: 2014

Nucleoside analogues have attracted much attention due to their potential biological activities. Amongst all synthetic nucleosides, C5-modified pyrimidines and C2- or C8-modified purines have been particularly studied. A large variety of palladium cross-coupling reactions, with a majority of them based on the Suzuki-Miyaura reaction, have been developed for preparing the desired nucleoside derivatives. Our objective is to focus this review on the Suzuki-Miyaura cross-coupling of nucleosides using methodologies compatible with green chemistry and sustainable development for one part and bioorthogonality for the other part, which means using aqueous medium and no protection/ deprotection steps. © 2014 the Partner Organisations.

Liu D.,CNRS Integrated Transformations of Renewable Matter | Lebovka N.I.,CNRS Integrated Transformations of Renewable Matter | Lebovka N.I.,Ukrainian Academy of Sciences | Vorobiev E.,CNRS Integrated Transformations of Renewable Matter
Food and Bioprocess Technology | Year: 2013

Treatments by high-voltage electrical discharges (HVED, needle-plate electrode geometry, U = 40 kV, tp ≈ 0.5 μs) and pulsed electric field (PEF, plate-plate electrode geometry, E = 5-40 kV/cm, tp ≈ 8.3 μs) were evaluated as tools for selective extraction of different intracellular components from the wine Saccharomyces cerevisiae (bayanus) yeasts in a 0.5% (w/w) aqueous suspension. The pulses in the form of damped oscillations and exponential decay were applied in HVED and PEF modes of treatment, respectively. The extraction efficiency results obtained using HVED and PEF techniques were compared with those for high-pressure homogenization technique. The HVED and PEF treatments always resulted in incomplete damage of yeast cells, though efficiency of HVED was higher than that of PEF. The high selectivity of extraction of ionic substances, proteins, and nucleic acids was demonstrated; e. g., electric pulse treatments at E = 40 kV/cm and N = 500 allowed extraction of ≈80% and ≈70% of ionic substances, ≈4% and ≈1% of proteins and ≈30% and ≈16% of nucleic acids in cases of HVED and PEF modes, respectively. © 2011 Springer Science+Business Media, LLC.

Polshettiwar V.,King Abdullah University of Science and Technology | Decottignies A.,CNRS Integrated Transformations of Renewable Matter | Len C.,CNRS Integrated Transformations of Renewable Matter | Fihri A.,CNRS Integrated Transformations of Renewable Matter
ChemSusChem | Year: 2010

Carbon-carbon cross-coupling reactions are among the most important processes in organic chemistry, and Suzuki-Miyaura reactions are among the most widely used protocols for the formation of carbon-carbon bonds. These reactions are generally catalyzed by soluble palladium complexes with various ligands. However, the use of toxic organic solvents remains a scientific challenge and an aspect of economical and ecological relevance. This Review will summarize various recently developed significant methods by which the Suzuki-Miyaura coupling was conducted in aqueous media, and analyzes if they are "real green" protocols. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Citeau M.,CNRS Integrated Transformations of Renewable Matter | Larue O.,CNRS Integrated Transformations of Renewable Matter | Vorobiev E.,CNRS Integrated Transformations of Renewable Matter
Water Research | Year: 2011

This paper deals with the influence of pH, salt and polyelectrolytes on the electro-dewatering (EOD) of agro-industrial sludge at 3% w/w of dry matter. Initially, a selection of polyelectrolyte types and doses was carried out for mechanical dewatering tests. Subsequent EOD tests were carried out in a laboratory two sided filter press at constant electric current density of 80 A/m2 and at pressure of 5 bar. It was found that whatever was the initial value of pH, salt content or polyelectrolyte type, the EOD progressed always towards the same equilibrium point at around 50% w/w of dry matter. EOD rate and energy input was not affected by the presence of polyelectrolyte whatever was its charge density and molecular weight. However, EOD rate and specific energy consumption and repartition of liquid at anode and cathode sides were strongly influenced by the salt content (adjusted by Na2SO4) or by the initial pH (adjusted with H2SO4 or NaOH). EOD performed better at lower salt content and at slightly acid pH. In optimum conditions, the process (EOD) required 2 h to reach dry matter of 40% w/w with specific energy consumption of 0.25 kWh/kg of water removed for the treatment of conditioned sludge. For comparison, compression without electric field at 5 bar required 11 h to reach 22% w/w of dry matter. This work emphasizes and demonstrates that the electrolytic hydroxide and hydronium ions formed at the electrodes have considerable influence in the course of EOD. © 2011 Elsevier Ltd.

Luo J.,CNRS Integrated Transformations of Renewable Matter | Ding L.,CNRS Integrated Transformations of Renewable Matter
Desalination | Year: 2011

In the dairy industry, the use of acid, alkaline cleaners and sanitizers affects wastewater characteristics and typically results in a highly variable pH, which will bring an impact on the wastewater on-line treatment. In this study, the effect of pH on treatment of diary wastewater by nanofiltration was investigated using a rotating disk membrane module. With increase of pH, NF membrane permeability was improved but concentration polarization increased. Due to a stronger electrostatic repulsion between salt ions and membrane at higher pH, permeate conductivity decreased. However, because of membrane swelling effect at alkaline pH, the neutral organic solutes passed through membrane more easily, leading to an increase of Chemical Oxygen Demand (COD) in permeate. Membrane fouling could be greatly alleviated at pH of 10, and the fouling layer was mainly caused by the adsorption of acid radicals-protein aggregates, which also resulted in pH reduction and conductivity increase in retentate. Real dairy wastewaters with different pH were also treated and the results were very similar to those of model solution, while membrane fouling was very sensitive to feed pH when pH was larger than 8. These results from laboratory-scale tests can serve as valuable guide for process control in industrial applications. © 2011 Elsevier B.V.

Boussetta N.,CNRS Integrated Transformations of Renewable Matter | Vorobiev E.,CNRS Integrated Transformations of Renewable Matter
Comptes Rendus Chimie | Year: 2014

The application of strong electric fields in gases, water and organic liquids has been studied for several years, because of its importance in electrical transmission processes and its practical applications in biology, chemistry, and electrochemistry. More recently, electrical discharges have been investigated and are being developed in water for enhancing the extraction of biocompounds from different raw materials. This paper reviews the current status of research on the application of high voltage electrical discharges for promoting cell disruption in aqueous suspension of biological materials, with particular emphasis on application to biocompounds extraction. © 2013 Académie des sciences.

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