Papers by Liliana Trevani
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ECS transactions, Jul 11, 2020
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Energy technology, Aug 3, 2018
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Journal of Solution Chemistry, Apr 18, 2008
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HAL (Le Centre pour la Communication Scientifique Directe), Sep 1, 2008
Communication OraleInternational audienceThe UV-visible spectra of aqueous o-, m-, and p-nitrophe... more Communication OraleInternational audienceThe UV-visible spectra of aqueous o-, m-, and p-nitrophenol were measured as a function of pH at temperatures from 50°C to 225°C at a pressure of 7 MPa. These were used to determine equilibrium constants for the acid ionization reaction of each isomer. The new experimental results, along with data from the literature, were used to develop a thermodynamic model to describe the dependence of ionization properties on temperature and pressure. The model yields predictions of the ionization constants for o-, m-, and pnitrophenol, log Ka, to at least 250°C and 20 MPa with an estimated uncertainty in log Ka of less than ± 0.06. Thermal decomposition studies, carried out by using the system as a stopped-flow reactor, showed that the three isomers are significantly more stable in HCl acid solutions. At temperatures above 225 oC and alkaline solutions, the residence time of the solution in the cell and the pre-heater is so long that significant changes in the spectra of the nitrophenolate species are observed in stopped-flow experiments as an indication of thermal decomposition reactions
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Journal of Chemical & Engineering Data, Jun 26, 2008
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The Journal of Chemical Thermodynamics, Feb 1, 2004
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Journal of Physical Chemistry B, Jun 7, 2019
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Nuclear Engineering and Design, Aug 1, 2013
ABSTRACT This paper presents an analysis of three new heat-transfer correlations developed for Su... more ABSTRACT This paper presents an analysis of three new heat-transfer correlations developed for SuperCritical (SC) carbon dioxide (CO2) flowing in vertical bare tubes. These correlations were developed from the large set of experimental data obtained at Chalk River Laboratories (CRL), AECL (2003). The dataset consists of tests performed in upward flow of CO2 inside 8-mm ID vertical Inconel-600 tube with a 2.208-m heated length. Data points compiled lie within a wide range of thermodynamic parameters - outlet pressures ranging from 7.4 to 8.8 MPa, mass fluxes from 900 to 3000 kg/m2s, inlet fluid temperatures from 20 to 40 C, and heat fluxes from 15 to 615 kW/m2; and for several combinations of wall and bulk-fluid temperatures that were below, at, or above the pseudocritical temperature. The objective of our research is to obtain reference dataset on heat transfer in SCCO2 and improve fundamental knowledge of the heat-transfer processes and handling of supercritical fluids. In general, heat-transfer process to a supercritical fluid is difficult to model, especially, when a fluid passes through the pseudocritical region, as there are very rapid variations in thermophysical properties of the fluid. Thus, it is important to investigate SC-fluid behaviour within these conditions. In general, SCCO2 was and is used as a modelling fluid instead of SC water due to its lower critical parameters. Also, SCCO2 is proposed to be used as a working fluid in the Brayton gas-turbine cycle as a secondary power cycle for some of the Generation-IV nuclear-reactor concepts such as Sodium-cooled Fast Reactor (SFR), Lead-cooled Fast Reactor (LFR) and Molten-Salt-cooled Reactor (MSR). In addition, SCCO 2 was proposed to be used in advanced air-conditioning and geothermal systems.
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Journal of Thermal Analysis and Calorimetry, Nov 5, 2014
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Journal of Solution Chemistry, May 2, 2023
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Frontiers in Energy Research, Mar 24, 2022
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The Journal of Chemical Thermodynamics, Dec 1, 2006
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This paper presents an analysis of three new heat-transfer correlations developed for supercritic... more This paper presents an analysis of three new heat-transfer correlations developed for supercritical carbon dioxide (CO2) flowing in vertical bare tubes. A large set of experimental data was obtained at Chalk River Laboratories (CRL) AECL. Heat-transfer tests were performed in upward flow of CO2 inside 8-mm ID vertical Inconel-600 tube with a 2.208-m heated length. Data points were collected at outlet pressures ranging from 7.4 to 8.8 MPa, mass fluxes from 900 to 3000 kg/m2s, inlet fluid temperatures from 20 to 40°C, and heat fluxes from 15 to 615 kW/m2; and for several combinations of wall and bulk-fluid temperatures that were below, at, or above the pseudocritical temperature. The objective of the present experimental research is to obtain reference dataset on heat transfer in supercritical CO2 and improve our fundamental knowledge of the heat-transfer processes and handling of supercritical fluids. In general, heat-transfer process to a supercritical fluid is difficult to model, especially, when a fluid passes through the pseudocritical region, as there are very rapid variations in thermophysical properties of the fluid. Thus, it is important to investigate supercritical-fluid behaviour within these conditions. In general, supercritical carbon dioxide was and is used as a modelling fluid instead of supercritical water due to its lower critical parameters compared to those of water. Also, supercritical carbon dioxide is proposed to be used as a working fluid in the Brayton gas-turbine cycle as a secondary power cycle for some of the Generation-IV nuclear-reactor concepts such as a Sodium-cooled Fast Reactor (SFR), Lead-cooled Fast Reactor (LFR) and Molten-Salt-cooled Reactor (MSR). In addition, supercritical carbon dioxide was proposed to be used in advanced air-conditioning and geothermal systems. Previous studies have shown that existing correlations deviate significantly from experimental Heat Transfer Coefficient (HTC) values, especially, within the pseudocritical range. Moreover, the majority of correlations were mainly developed for supercritical water, and our latest results indicate that they cannot be directly applied to supercritical CO2 with the same accuracy as for water. Therefore, new empirical correlations to predict HTC values were developed based on the supercritical CO2 dataset. These correlations calculate HTC values with an accuracy of ±30% (wall temperatures with accuracy of ±20%) for the analyzed dataset.
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Journal of Thermal Analysis and Calorimetry, Mar 12, 2009
Autothermal operation of pressure oxidation pro-cesses requires knowledge of the exothermic reac-... more Autothermal operation of pressure oxidation pro-cesses requires knowledge of the exothermic reac-tions in hydrometallurgical operations. Consequently, the measurement or calculation of the reaction enthalpy is an important factor in the design of such operations. Even if ...
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International Journal of Hydrogen Energy, May 1, 2016
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International Journal of Hydrogen Energy, May 1, 2010
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Journal of Power Sources, Oct 1, 2015
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Applied Catalysis B-environmental, Aug 1, 2017
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Meeting abstracts, May 1, 2020
Global energy demand has significantly increased in the last decades, and consequently, the envir... more Global energy demand has significantly increased in the last decades, and consequently, the environmental problems associated with the use of fossil fuels. More sustainable energy sources are required, and it is imperative to develop more efficient energy storage and conversion devices. In this context, batteries and fuel cells are promising options for stationary, portable, and transport applications.[1] Unfortunately, both polymer electrolyte membrane fuel cells (PEMFCs) and metal-air batteries are limited by the need for high Pt loadings in the cathode due to kinetic limitations imposed by the sluggish oxygen reduction reaction (ORR).[2] The conditions in the cathode can also result in the degradation of the carbon support (carbon corrosion) and Pt agglomeration, dislodgement, and dissolution.[3] Efforts aimed to solve these problems have intensified, principally the search for new catalysts materials to reduce or eliminate the need for Pt.[4] In the framework of these initiatives, heteroatoms-doped carbons obtained by carbonization of organic polymer gels (OPGs) are seen as attractive candidates for achieving some of these goals.[5] Even though resorcinol-formaldehyde polymers have been the most extensively studied, other precursors have been recently investigated for applications in batteries and supercapacitors.[6] In this study, high surface area mesoporous carbon materials with variable N and O contents were produced by carbonization of melamine-formaldehyde (MF) and resorcinol-formaldehyde (RF) polymer gels in the presence of SiO2 nanoparticles (20 to 200 nm) as hard-templates. Carbon products with up to 8 N-atom% and surface areas up to 500 m2/g were obtained by carbonization of nitrogen-rich melamine polymers (MF-C) depending on the annealing conditions (950°C or 1500°C). By adopting a similar approach, carbons with variable oxygen and nitrogen content were prepared by the combustion of resorcinol-formaldehyde (RF-C) and resorcinol-melamine-formaldehyde (RMF-C) polymers. The materials structure and chemical composition have been extensively investigated using a plethora of different techniques. Pt/MF-C and Pt/RF-C samples were prepared by an impregnation method to evaluate the stability of these catalysts under oxidizing and acidic conditions, as well as their catalytic activity toward the ORR. It was found that an increase in annealing temperature from 950 to 1500 oC resulted in a significant improvement in stability upon cycling the potential in accelerated ageing tests in acid media (0 to 1.4 V vs NHE) comparable or even better than the benchmark material Pt/Vulcan, and a preferential 4-electron reduction pathway for the ORR, as required for fuel cells and metal-air batteries applications. Preliminary data for the reduction of oxygen on Fe/MF-C and Fe/RF-C samples are underway, and preliminary results will also be presented. References [1] Yang et al., Chem. Rev., 111, 3577-3613, 2011. [2] Gasteiger et al., Appl. Catal., B56,9-35, 2005/Li Y. and Lu J., ACS Energy Lett., 2(6), 1370-1377, 2017. [3] Macauley et al., J. Electrochem. Soc., 165(6), F3148-F3160, 2018. [4] Shao et al., Chem. Rev., 116, 3594-3657, 2016. [5] Tesfaye et al., Sci. Rep., 9, 479, 2019. [6] Li et al., Micropor. Mesopor. Mat., 279, 293-315, 2019.
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Papers by Liliana Trevani