Search results for " reactor"

Surfactant Assisted Polymerization of Tetrafluoroethylene in Supercritical Carbon Dioxide with a Pilot Scale Batch Reactor.

2008

Chain-free radical polymerization of tetrafluoroethylene (TFE) was carried out in supercritical carbon dioxide (scCO2), at 50 °C and 121–133 bar, with tertiary-amyl-per-pivalate as a free radical initiator, using a 5-L pilot scale batch reactor. Experiments were carried out both in the absence and in the presence of perfluoropolyether (PFPE) carboxylate surfactants. Stabilizers were employed under the free acid form and as sodium and calcium salts. An expanded fibrillated poly(TFE) was obtained in all experiments. In the case of surfactant-free polymerizations, the product was mainly constituted by irregular shape macroparticles having size in the range 200–500 μm. Quite interestingly, when…

Erratum to “New time-dependent Monte Carlo algorithm designed to model three-phase batch reactor processes: applications on 2,4-dinitro-toluene hydro…

2003

Erratum to “New time-dependent Monte Carlo algorithm designed to model three-phase batch reactor processes: applications on 2,4-dinitro-toluene hydrogenation on Pd/C catalysts” [Chem. Eng. J. 91 (2003) 133–142] Giampaolo Barone a,b, Dario Duca a,b,∗ a Dipartimento di Chimica Inorganica ed Analitica, Universita di Palermo, Viale delle Scienze, I-90128 Palermo, Italy b Dipartimento di Scienze Farmaceutiche, Universita di Salerno, Via Ponte don Melillo, I-84084 Fisciano, Salerno, Italy

1988

Terminaison d'un polystyrene lineaire telechelique avec des anions aux deux extremites a l'aide d'un agent de terminaison bifonctionnel et une haute dilution

Measurement of θ13 in Double Chooz using neutron captures on hydrogen with novel background rejection techniques

2016

The Double Chooz collaboration presents a measurement of the neutrino mixing angle θ[subscript 13] using reactor [bar over ν[subscript e]] observed via the inverse beta decay reaction in which the neutron is captured on hydrogen. This measurement is based on 462.72 live days data, approximately twice as much data as in the previous such analysis, collected with a detector positioned at an average distance of 1050 m from two reactor cores. Several novel techniques have been developed to achieve significant reductions of the backgrounds and systematic uncertainties. Accidental coincidences, the dominant background in this analysis, are suppressed by more than an order of magnitude with respec…

Removal of bis (2-ethylhexyl) phthalate from reject water in a nitrogen-removing sequencing batch reactor.

2003

Reject water from sewage sludge processing may contain high concentrations of nutrients and organic pollutants and cause internal pollution load at a sewage treatment plant (STP) if circulated to the headworks of an STP. In the present study removal of nitrogen and bis (2-ethylhexyl) phthalate (DEHP) from reject water was studied in two sequencing batch reactors (SBRs) with different aerobic/anoxic periods during a 6-h total cycle period. Ammonia-nitrogen (NH(4)-N) was almost totally removed in both reactors, apparently by nitrification throughout the run, while denitrification declined with decreasing SCOD in the influent resulting in an increase in the effluent nitrate-nitrogen (NO(3)-N) …

TAGS measurements for neutrino physics and applications

2017

En la actualidad un gran número de temas de interés en Física Nuclear continúan planteando interrogantes fundamentales. Una de las fuentes de información más esclarecedoras es el proceso de la desintegración beta. Gracias al estudio experimental de este fenómeno en núcleos alejados de la estabilidad, es posible extraer valiosa información sobre estructura nuclear. En esa línea, esta tesis se centra en la determinación de las intensidades beta que pueblan los estados excitados del núcleo hijo en la desintegración beta de núcleos exóticos de gran interés. Para ello se ha utilizado la técnica de Espectroscopía gamma de Absorción Total (TAGS, por sus siglas en inglés), basada en el uso de grand…

Effect of long-term salinity increase on nitritation and denitritation kinetics in activated sludge and granular sludge reactors

2017

The aim of this work was to investigate the effects of moderate and drastic long-termincrease of salinity.Particularly, the study was aimed at assessing the shock effecton nitritationand denitritation kineticsof halophilic biomass inboth forms:flocculent activated sludge and granular sludge.

Heterogeneous Photocatalysis for Selective Formation of High-Value-Added Molecules: Some Chemical and Engineering Aspects

2018

This review deals with the parameters that influence heterogeneous photocatalysis (PC) for selective synthesis of high-value chemicals by itself or in combination with other technologies. In particular, the parameters related to the photocatalysts, such as crystallinity degree, type of polymorph, surface acid-base properties, exposure of particular crystalline facets, coupling of different semiconductors, position of the valence and conduction band edge, addition of doping agents, and those related to the reaction system, such as setup configuration and reactor geometry, type of solvent, type and amount of photocatalyst, affecting the selectivity toward specific products are described and d…

Modelling of the hydrodynamics of concurrent gas and liquid flow through packed bed

2016

The aim of the present study is to simulate concurrent gas and liquid flow through packed bed in the gas continuous flow regime (GCF) and continuity shock waves regime (CSW) using computational fluid dynamics (CFD). The application of multiple gas-liquid-solid model requires the knowledge of relationships determining interactions between phases. The exchange coefficients of these forces were defined by means of equations suggested by ATTOU et al. (1999). As a result of the computational simulation the following data were obtained: gas pressure drop in the bed, volume fraction distribution of a given phase (liquid and gas holdups) along the packing and its mean value in the reactor. The comp…

2015

One-pot combination of the in-situ generation of hydrogen peroxide (H2O2) with selective oxidation reactions enhances the environmental and economic attractiveness of the use of H2O2 as green oxidant at industrial scale. This tandem reaction improves not only the safety aspects associated to H2O2 storage and transportation but also reduces the capital and operation costs. This review covers the progress in the field focussing on the areas of catalysis development, mechanistic understanding and engineering approaches (such as membrane reactors) for specific systems involving epoxidation of propylene oxide, hydroxylation of benzene, oxygenate synthesis from methane and Fenton processes, highl…