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Chen X.Y.,Laval University | Chen X.Y.,Center National en Electrochimie et en Technologies Environnementales | Vinh-Thang H.,Laval University | Rodrigue D.,Laval University | Kaliaguine S.,Laval University
RSC Advances | Year: 2014

Macrovoid structured mixed matrix membranes (MMMs) composed of nano-size (200 nm) silica particles and co-polyimide were prepared from 6FDA-ODA-DAM (6FDA = 4,4′-(hexafluoroiso-propylidene)diphthalic anhydride; ODA = 4,4′-oxidianiline; DAM = 1,3,5-trimethyl-2,6-phenylenediamine) with different proportions (1:1 and 1:4) and tetraethoxysilane (TEOS) via the sol-gel method. The separation performance of MMMs with 6FDA-ODA-DAM treated at high temperature (450 °C) was excellent for CO2/CH4 separation (for 6FOD-ODA-DAM (1:1): CO2 permeability ∼265 Barrer and CO2/CH4 selectivity ∼32; for 6FOD-ODA-DAM (1:4): CO2 permeability ∼302 Barrer and CO2/CH4 selectivity ∼25). Remarkably, the best membrane could resist pressure up to 600 psi without any loss of permselectivity. The CO2/CH4 separation performance of a series of silica-6FDA-ODA-DAM(11) MMMs with different SiO2 loadings is theoretically predicted using a modified Maxwell model where both gas permeability and macrovoid shape factor are simultaneously considered as adjustable parameters. Applying the optimized values, the modified Maxwell model predictions were in excellent agreement with experimental permeability data (less than 2% deviation). © 2014 The Royal Society of Chemistry. Source


Ferdowsi M.,Universite de Sherbrooke | Veillette M.,Universite de Sherbrooke | Ramirez A.A.,Universite de Sherbrooke | Ramirez A.A.,Center National en Electrochimie et en Technologies Environnementales | And 2 more authors.
Water, Air, and Soil Pollution | Year: 2016

An inorganic-based bed biofilter was used to eliminate methane (CH4) from an air stream under pseudo steady state, transient state (shock loads), and starvation conditions. Under pseudo steady state conditions, the effect of inlet CH4concentration in the range of 1000–13,000 ppmv on the biofilter performance was studied. The air flow rate was kept constant at 3 L min−1, corresponding to an empty bed residence time (EBRT) of 6 min. The flexibility of the biofilter under transient conditions was evaluated by two strategies: Inlet loads (IL) varied from 13 to 65 g m−3 h−1by changing inlet concentrations from 2000 to 10,000 ppmv or by changing air flow rates varied from 3 to 15 L min−1, separately. Finally, the effects of nutrients and CH4starvations were evaluated. The biofilter performance was promising for the treatment of a wide range of concentrations of off gas emissions polluted with CH4(1000–13,000 ppmv). For CH4concentrations ranging from 1000 to 4000 ppmv, the removal efficiency (RE) remained higher than 75 %. The maximum elimination capacity (EC) obtained in this study was 45 g m−3 h−1for an IL of 87 g m−3 h−1. In case of sudden variations of ILs (13 to 65 g m−3 h−1) either by changing the inlet concentration or by modifying the flow rate, the responses of the biofilter were almost instantaneous. © 2016, Springer International Publishing Switzerland. Source


Ghorbel L.,INRS - Institute National de la Recherche Scientifique | Rouissi T.,INRS - Institute National de la Recherche Scientifique | Brar S.K.,INRS - Institute National de la Recherche Scientifique | Lopez-Gonzalez D.,University of Castilla - La Mancha | And 2 more authors.
Waste Management | Year: 2015

This study aims to underline the huge potential in Canada of adding value to cardboard and compost as a renewable fuel with a low ecological footprint. The slow pyrolysis process of lined cardboard and compost blend was investigated. Thermal behavior was investigated by thermogravimetric analysis coupled with mass spectrometry (TGA-MS). The thermal profiles are presented in the form of TGA/DTG curves. With a constant heating rate of 10°C/min, two parameters, temperature and time were varied. Cardboard decomposition occurred mostly between 203°C and 436°C, where 77% of the sample weight was decomposed. Compost blend decomposition occurred mostly between 209°C and 373°C, with 23% of weight. The principal gaseous products that evolved during the pyrolysis were H2O, CO and CO2. As a result, slow pyrolysis led to the formation of biochar. High yield of biochar from cardboard was found at 250°C for a duration of 60min (87.5%) while the biochar yield from the compost blend was maintained constant at about 31%. Finally, kinetic parameters and a statistical analysis for the pyrolysis process of the cardboard and compost samples have been investigated. Both materials showed a favorable thermochemical behavior. However, unlike cardboard, compost pyrolysis does not seem a promising process because of the low superior calorific and biochar values. © 2015 Elsevier Ltd. Source


Fernandez-Lopez M.,University of Castilla - La Mancha | Puig-Gamero M.,University of Castilla - La Mancha | Lopez-Gonzalez D.,CNRS Research on Catalysis and Environment in Lyon | Avalos-Ramirez A.,Center National en Electrochimie et en Technologies Environnementales | And 2 more authors.
Bioresource Technology | Year: 2015

The valorization of three different manure samples via pyrolysis and combustion processes was evaluated. Dairy manure (sample Pre) was biologically pretreated by anaerobic digestion (sample Dig R) whereas swine manure (sample SW) was pretreated by a biodrying process. Thermal behavior of manure samples were studied by means of thermogravimetric analysis coupled with mass spectrometry (TGA-MS). These processes could be divided into four general stages: dehydration, devolatilization, char transformation (oxidation for combustion) and inorganic matter decomposition. The main differences observed among the samples were attributed to their different composition and pretreatment. The economic feasibility, energetic and environmental impacts of pyrolysis and combustion technologies for dairy samples were carried out by means of life cycle assessment (LCA) methodology. Four different scenarios were analyzed. The economic feasibility of the pyrolysis process was demonstrated, being sample Dig R the best environmental option. However, the combustion of sample Pre was the best energetic option. © 2015 Elsevier Ltd. Source


Lopez-Gonzalez D.,CNRS Research on Catalysis and Environment in Lyon | Avalos-Ramirez A.,Center National en Electrochimie et en Technologies Environnementales | Giroir-Fendler A.,CNRS Research on Catalysis and Environment in Lyon | Godbout S.,Institute Of Recherche Et Of Developpement En Agroenvironnement | And 3 more authors.
Energy | Year: 2015

Combustion characteristics of two woody crops (BP (black spruce and Pinus banksiana mixtures) and W (willow)) and three herbaceous non-perennial energy crops (CR (common reed), RP (reed phalaris) and S (switchgrass)) were studied by means of TGA (thermogravimetric analysis) and DSC (differential scanning calorimetry) coupled with MS (mass spectrometry). The combustion process of these biomasses is divided into two stages: devolatilization and char oxidation. TGA data showed that sample BP had the best ignition characteristics (burnout temperature of 507 °C). However, DSC analysis demonstrated that samples W and RP released a higher amount of combustion heat (>8 kJ/g). Kinetics was evaluated assuming single separate reactions for each combustion stage using PMSM (pseudo multi-component separate-stage models). The process was successfully modeled obtaining the maximum error of ±3.35% for the sample S. CO, CO2 and H2O were the main components obtained during the combustion process. Nitrogen compounds (NO, NO2 and HCN) were found in higher proportions that sulfur compounds (SO and SO2). Nitrogen compounds were released in both combustion stages, whereas sulfur compounds evolved mainly in the low temperature range. Other pollutants were found in lower concentrations (CH3Cl and C6H6). © 2015 Elsevier Ltd. Source

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