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Synthopetrol, French National Center for Scientific Research, School of Chemistry, Physics and Electronics, Lyon | Date: 2017-03-08

The present invention relates to the use of a heterogeneous solid catalyst comprising or consisting of a metal complex linked by covalent bonds and / or by Van der Waals type interactions on a magnetic carrier for the implementation of a hydrotreatment reaction of gas derived from the pyrolysis of a substrate, the said hydrotreatment reaction being carried out with hydrogen and with said gas in the presence of said catalyst and leading to a gaseous phase, said gaseous phase leading by a step of cooling to the production of a liquid phase formed of liquid biofuel.

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.

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.

Ho L.,SA Water Corporation | Ho L.,University of Adelaide | Lambling P.,School of Chemistry, Physics and Electronics, Lyon | Bustamante H.,Sydney Water | And 2 more authors.
Water Research | Year: 2011

Cylindrospermopsin (CYN) and microcystin are two potent toxins that can be produced by cyanobacteria in drinking water supplies. This study investigated the application of powdered activated carbon (PAC) for the removal of these toxins under conditions that could be experienced in a water treatment plant. Two different PACs were evaluated for their ability to remove CYN and four microcystin variants from various drinking water supplies. The removal of natural organic material by the PACs was also determined by measuring the levels of dissolved organic carbon and UV absorbance (at 254 nm). The PACs effectively removed CYN and the microcystins from each of the waters studied, with one of the PACs shown to be more effective, possibly due to its smaller particle diameter. No difference in removal of the toxins was observed using PAC contact times of 30, 45 and 60 min. Furthermore, the effect of water quality on the removal of the toxins was minimal. The microcystin variants were adsorbed in the order: MCRR > MCYR > MCLR > MCLA. CYN was found to be adsorbed similarly to MCRR. © 2011 Elsevier Ltd.

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.

Doumeche B.,University Claude Bernard Lyon 1 | Doumeche B.,French National Center for Scientific Research | Doumeche B.,INSA Lyon | Doumeche B.,School of Chemistry, Physics and Electronics, Lyon | And 4 more authors.
Electrochemistry Communications | Year: 2010

NADH oxidation catalysts are extremely important in the field of electrochemical biosensors and enzymatic biofuel cells. Based on the growing diazonium chemistry, we synthesized the diazonium salt of the well-known NADH mediator toluidine blue O. The electrochemical reduction of the diazonium moiety by cyclic voltammetry onto a screen-printed electrode leads to an electrocatalyst suitable for the oxidation of NADH. The amperometric response for its oxidation shows a maximal current of 1.2 μA ([NADH] = 100 μM). Based on electrochemical measurements, the surface coverage is found to be 3.78 × 10- 11 mol cm- 2 and the heterogeneous standard rate constant kh is 1.21 ± 0.16 s- 1. The sensitive layer for the oxidation of NADH is improved by electrografting the diazonium salt with a potentiostatic method. Both the surface coverage and the heterogeneous standard rate constant kh are improved and found to be 6.08 ± 0.63 × 10- 11 mol cm- 2 and ~ 5.02 s- 1, respectively. The amperometric response is also improved by an 8 fold factor, reaching 9.87 μA ([NADH] = 120 μM). These remarkably high values for screen-printed electrodes are comparable to glassy carbon electrodes making this method suitable for low-cost bioelectronical devices. © 2010 Elsevier B.V.

Solans-Monfort X.,Autonomous University of Barcelona | Chow C.,School of Chemistry, Physics and Electronics, Lyon | Chow C.,University of British Columbia | Goure E.,School of Chemistry, Physics and Electronics, Lyon | And 7 more authors.
Inorganic Chemistry | Year: 2012

DFT(B3PW91) calculations have been carried out to propose a pathway for the N2 cleavage by H2 in the presence of silica-supported tantalum hydride complexes [(≡ SiO)2TaHx] that forms [(≡SiO)2Ta(NH)(NH2)] (Science2007, 317, 1056). The calculations, performed on the cluster models {μ-O[(HO)2SiO] 2}TaH1 and {μ-O[(HO)2SiO] 2}TaH3, labelled as (≡SiO)2TaH x (x = 1, 3), show that the direct hydride transfers to coordinated N-based ligands in (≡SiO)2TaH(η2-N2) and (≡SiO)2TaH(η2-HNNH) have high energy barrier barriers. These high energy barriers are due in part to a lack of energetically accessible empty orbitals in the negatively charged N-based ligands. It is shown that a succession of proton transfers and reduction steps (hydride transfer or 2 electron reduction by way of dihydride reductive coupling) to the nitrogen-based ligands leads to more energetically accessible pathways. These proton transfers, which occur by way of heterolytic activation of H2, increase the electrophilicity of the resulting ligand (diazenido, N 2H-, and hydrazido, NHNH2-, respectively) that can thus accept a hydride with a moderate energy barrier. In the case of (≡SiO)2TaH(η2-HNNH), the H 2 molecule that is adding across the Ta-N bond is released after the hydride transfer step by heterolytic elimination from (≡SiO) 2TaH(NH2)2, suggesting that dihydrogen has a key role in assisting the final steps of the reaction without itself being consumed in the process. This partly accounts for the experimental observation that the addition of H2 is needed to convert an intermediate, identified as a diazenido complex [(≡SiO)2TaH(η 2-HNNH)] from its ν(N-H) stretching frequency of 3400 cm -1, to the final product. Throughout the proposed mechanism, the tantalum remains in its preferred high oxidation state and avoids redox-type reactions, which are more energetically demanding. © 2012 American Chemical Society.

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.

Centi G.,Messina University | Quadrelli E.A.,School of Chemistry, Physics and Electronics, Lyon | Perathoner S.,Messina University
Energy and Environmental Science | Year: 2013

Replacement of part of the fossil fuel consumption by renewable energy, in particular in the chemical industry, is a central strategy for resource and energy efficiency. This perspective will show that CO2 is the key molecule to proceed effectively in this direction. The routes, opportunities and barriers in increasing the share of renewable energy by using CO2 reaction and their impact on the chemical and energy value chains are discussed after introducing the general aspects of this topic evidencing the tight integration between the CO2 use and renewable energy insertion in the value chain of the process industry. The focus of this perspective article is on the catalytic aspects of the chemistries involved, with an analysis of the state-of-the-art, perspectives and targets to be developed. The reactions discussed are the production of short-chain olefins (ethylene, propylene) from CO2, and the conversion of carbon dioxide to syngas, formic acid, methanol and dimethyl ether, hydrocarbons via Fischer-Tropsch synthesis and methane. The relevance of availability, cost and environmental footprints of H2 production routes using renewable energies is addressed. The final part discusses the possible scenario for CO2 as an intermediary for the incorporation of renewable energy in the process industry, with a concise roadmap for catalysis needs and barriers to reach this goal. © 2013 The Royal Society of Chemistry.

Toihria I.,School of Chemistry, Physics and Electronics, Lyon | Thierry T.,School of Chemistry, Physics and Electronics, Lyon
7th International Conference on Design and Technology of Integrated Systems in Nanoscale Era, DTIS 2012 | Year: 2012

Analog circuit design is often based on a large number of simulations which strongly depends on the mastery of CAD tools and competence of the designer. In this context, the automated design of analog architectures becomes a necessity of design to solve the problem of simulation time. More importantly, accelerating the design cycle of the analog block, taking into account many constraints and finally formalizing the experience of analogiciens designers. In this paper we present a method for modeling the performance parameters of analog architectures, this is for the optimization of optimal sizing of transistors constituting the circuit to achieve the desired characteristics. This work is done following a modeling of the functioning of the Operational Amplifier using mathematical formulation software Maxima. The formulation is based on the SPICE level 1 model of the MOS transistor. Finally, the elaboration of the model is developed under MATLAB. The proposed method is presented and applied to the modeling and design of a Folded Cascode bulk driven OTA using a 0.35μm CMOS technology. Simulations with Cadence Spectrum are presented and compared with manual calculations and also to numerical calculations that have shown the effectiveness of the proposed methodology. Then, we determine the optimal parameters of the operational amplifier, which accord, maximum, to the desired specifications. © 2012 IEEE.

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