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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. Source

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. Source

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. Source

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. Source

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. Source

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