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Quadrelli E.A.,School of Chemistry, Physics and Electronics, Lyon | Centi G.,Messina University | Duplan J.-L.,French Institute of Petroleum | Perathoner S.,Messina University
ChemSusChem | Year: 2011

This Review introduces this special issue of ChemSusChem dedicated to CO 2 recycling. Its aim is to offer an up-to-date overview of CO 2 chemical utilization (inorganic mineralization, organic carboxylation, reduction reactions, and biochemical conversion), as a continuation and extension of earlier books and reviews on this topic, but with a specific focus on large-volume routes and projects/pilot plants that are currently emerging at (pre-)industrial level. The Review also highlights how some of these routes will offer a valuable opportunity to introduce renewable energy into the existing energy and chemical infrastructure (i.e., "drop-in" renewable energy) by synthesis of chemicals from CO 2 that are easy to transport and store. CO 2 conversion therefore has the potential to become a key pillar of the sustainable and resource-efficient production of chemicals and energy from renewables. Emerging large-scale CO 2 conversion routes, with an overview of projects and pilot plants that are currently (nearly) at an industrial level are the subject of this Review. These include inorganic mineralization, organic carboxylation, reduction, and biochemical conversion. These developments show the potential of CO 2 as a green molecule that enables the sustainable and resource-efficient production of chemicals and energy © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Maxut A.,CNRS Research on Catalysis and Environment in Lyon | Noziere B.,CNRS Research on Catalysis and Environment in Lyon | Fenet B.,School of Chemistry, Physics and Electronics, Lyon | Mechakra H.,CNRS Research on Catalysis and Environment in Lyon
Physical Chemistry Chemical Physics | Year: 2015

Imidazoles have numerous applications in pharmacology, chemistry, optics and electronics, making the development of their environmentally-friendly synthetic procedures worthwhile. In this work, the formation of imidazole, imidazole-2-carboxaldehyde, and 2,2-bis-1H-imidazole was investigated in the self-reaction of glyoxal and its cross-reactions with each of these compounds in aqueous solutions of inorganic ammonium salts at pH =7. Such conditions are relevant both as cheap and environmentally-friendly synthetic procedures and for the chemistry of natural environments where NH4+ is abundant, such as in atmospheric aerosols. These reactions were investigated both by 1H-NMR and UV-Vis absorption spectroscopy at room temperature with the objective to determine the formation pathways of the three imidazoles and the parameters affecting their yields, to identify the optimal conditions for their synthesis. The results show that only the simplest imidazole is produced by the self-reaction of glyoxal and that imidazole-2-carboxaldehyde and 2,2-bis-1H-imidazole are produced by cross-reactions of glyoxal with imidazole and imidazole-2-carboxaldehyde, respectively. The yields of imidazole-2-carboxaldehyde and 2,2-bis-1H-imidazole formed by the cross-reactions were close to unity, but the yield of imidazole formed by the self-reaction of glyoxal, YIm, was small and varied inversely with the initial glyoxal concentration, [G]0: YIm > 10% only for [G]0 < 0.1 M. The latter result was attributed to the kinetic competition between the imidazole-forming condensation pathway and the acetal/oligomer formation pathway of the glyoxal self-reaction and constitutes a bottleneck for the formation of higher imidazoles. Other parameters such as pH and the NH4+ concentration did not affect the yields. Thus, by maintaining small glyoxal concentrations, high imidazole yields can be achieved in environmentally-friendly aqueous ammonium solutions at neutral pH. Under the same conditions, higher yields are expected expected from substituted carbonyl compounds, regardless of their concentration, as they produce less acetals. © the Owner Societies 2015. Source

Guerin H.,4 rue Commandant Faurax | Guerin H.,School of Chemistry, Physics and Electronics, Lyon
Journal of Molecular Liquids | Year: 2012

In this short communication, it is shown that the triangular-well fluid analytic equation of state (EOS) recently proposed by Betancourt-Cárdenas et al. [Mol. Phys. 105 (2007) 2987] within the framework of the Barker-Henderson perturbation theory of fluids with the macroscopic compressibility approximation (BH-MCA) can be improved in two ways. First it is cast into a more compact form, which avoids the calculations of seventy-five numerical coefficients. Secondly, by using a more accurate expression of the hard-sphere radial distribution function (HS-RDF), g HS(r), the accuracy of the analytical expression of the free energy second-order term is improved, being in agreement with its BH-MCA numerical evaluation. For short-range triangular-well potentials, the present EOS also leads to second-order residual internal energies and reduced pressures in better agreement with the molecular simulations than the Betancourt-Cárdenas et al. results. © 2012 Elsevier B.V. All rights reserved. Source

Ho L.,SA Water Corporation | Ho L.,University of Adelaide | Grasset C.,School of Chemistry, Physics and Electronics, Lyon | Hoefel D.,SA Water Corporation | And 7 more authors.
Water Research | Year: 2011

Granular media filtration was evaluated for the removal of a suite of chemical contaminants that can be found in wastewater. Laboratory- and pilot-scale sand and granular activated carbon (GAC) filters were trialled for their ability to remove atrazine, estrone (E1), 17α-ethynylestradiol (EE2), N-nitrosodimethylamine (NDMA), N-nitrosomorpholine (NMOR) and N-nitrosodiethylamine (NDEA). In general, sand filtration was ineffective in removing the contaminants from a tertiary treated wastewater, with the exception of E1 and EE2, where efficient removals were observed after approximately 150 d. Batch degradation experiments confirmed that the removal of E1 was through biological activity, with a pseudo-first-order degradation rate constant of 7.4 × 10-3 h-1. GAC filtration was initially able to effectively remove all contaminants; although removals decreased over time due to competition with other organics present in the water. The only exception was atrazine where removal remained consistently high throughout the experiment. Previously unreported differences were observed in the adsorption of the three nitrosamines, with the ease of removal following the trend, NDEA > NMOR > NDMA, consistent with their hydrophobic character. In most instances the removals from the pilot-scale filters were generally in agreement with the laboratory-scale filter, suggesting that there is potential in using laboratory-scale filters as monitoring tools to evaluate the performance of pilot- and possibly full-scale sand and GAC filters at wastewater treatment plants. © 2011 Elsevier Ltd. Source

Ho L.,SA Water Corporation | Ho L.,University of Adelaide | Hoefel D.,SA Water Corporation | Hoefel D.,University of Adelaide | And 6 more authors.
Journal of Hazardous Materials | Year: 2010

Microcystins are potent hepatotoxins that can be produced by cyanobacteria. These organisms can proliferate in wastewaters due to a number of factors including high concentrations of nutrients for growth. As treated wastewaters are now being considered as supplementary drinking water sources, in addition to their frequent use for irrigated agriculture, it is imperative that these wastewaters are free of toxins such as microcystins. This study investigated the potential for biodegradation of microcystin-LR (MCLR) in wastewaters through a biological sand filtration experiment and in static batch reactor experiments. MCLR was effectively removed at a range of concentrations and at various temperatures, with degradation attributed to the action of microorganisms indigenous to the wastewaters. No hepatotoxic by-products were detected following the degradation of MCLR as determined by a protein phosphatase inhibition assay. Using TaqMan polymerase chain reaction, the first gene involved in bacterial degradation of MCLR (mlrA) was detected and the responsible bacteria shown to increase with the amount of MCLR being degraded. This finding suggested that the degradation of MCLR was dependent upon the abundance of MCLR-degrading organisms present within the wastewater, and that MCLR may provide bacteria with a significant carbon source for proliferation; in turn increasing MCLR removal. © 2010 Elsevier B.V. Source

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