Concern for the health of the natural environment is growing as human population grows. Recently,... more Concern for the health of the natural environment is growing as human population grows. Recently, renewed attention has been given to the environmental impact of fires and the fire implications of sustainability choices made in the built environment. To properly understand the environmental impact of fires, however, it is crucial that we can estimate fire emissions. This paper explores the concept of fire emissions and emission factors and investigates the potential to use small scale testing to develop emission factors for fire emissions. The findings show that there is a potential to use dynamic tests such as the cone calorimeter (CC, ISO 5660) and fire propagation apparatus (FPA, ISO 12136) to develop emission factors to estimate larger scale fire emissions, at least for CO and CO 2 emissions. While there is a spread of data from between the CC or FPA and the medium scale tests, this is of the same order or less than the spread between the two small scale tests. The spread in emission factor values from the various tests is smaller for CO 2 than for CO and greatest for small CO-emission factors (< 10 g/kg). More work is needed to similarly characterise a broad range of species.
There is no doubt that additive manufacturing (AM) technologies bring new and valuable assets to ... more There is no doubt that additive manufacturing (AM) technologies bring new and valuable assets to innovation: it makes possible to forge objects that were impossible to forge before, objects can be customized at will, etc. Jeremy Rifkin, an American economic and social theorist, even foresees in additive manufacturing technologies a looming third industrial revolution.
Due to environmental and energy concerns, batteries for electric vehicles are highly studied and ... more Due to environmental and energy concerns, batteries for electric vehicles are highly studied and developed. They are mainly based on lithium-ion technology, considered more efficient in energy density. Carbonate mixtures used as electrolyte solvents could lead to safety issues due to their high flammability and low flash points. Formulating electrolyte solutions with nonvolatile and nonflammable ionic liquids (ILs) instead of carbonate mixtures could be safer1 as they have low vapour pressure and high flash point.2 Moreover, they are good ionic conductors, present wide electrochemical window and high decomposition temperature (Td).3 But little information is available on their behaviour under abuse conditions like car crashes or any abnormal use (shortcut, overheat). In order to understand the possible decomposition mechanisms of ILs and their mixture with lithium salt during abuse tests, a thermodynamic study of these compounds was carried out. A critical literature study of the Td determined by thermogravimetric analysis (TGA) and consequent experiments highlighted the stability of the NTf2 anion combined with two cationic families: imidazolium and pyrrolidinium.4 We chose 1-butyl-3-methylimidazolium [C1C4Im] and 1-butyl-1-methylpyrrolidinium [PYR14] cations, bis(trifluoromethanesulfonyl)imide [NTf2] anion. The electrolytes were composed of their mixture with 1 mol.L-1 of LiNTf2 and referred to as [C1C4Im][Li][NTf2] and [PYR14][Li][NTf2]. Nevertheless, TGA does not give sufficient information on the nature of volatile emissions, so the thermal decomposition of [C1C4Im][NTf2] and [PYR14][NTf2] and their corresponding electrolytes was studied. Long term experiments with different techniques (2 to 15 h at 350°C) showed the highest stability of imidazolium-based solutions (Figure 1). For both families, the volatile decomposition products were mainly identified as butene isomers. Recombined alkyl cations (e.g. C1Im, C4Im, C4C4Im and C1C1Im) were detected in the residual liquid phases, implying that a degradation with no mass loss occurred. Figure 1: Long term stability test by TGA of IL-based electrolytes, neat ILs and lithium salt at 350 °C for 15 h Flammability and heat of combustion were studied with a fire propagation apparatus. The solutions were found very weakly combustible, and LiNTf2 showed a flame retardant effect. Flammable gases were emitted due to cation decomposition, and the anion decomposition formed toxic effluents.5 Figure 2: Heat release rate profiles of neat ILs and corresponding electrolytes showing good resistance to ignition (ca.5 min) Then the electrolytes [C1C4Im][Li][NTf2] and [PYR14][Li][NTf2] were used in batteries constituted of Li4Ti5O12 and LiNi1/3Co1/3Mn1/3O2 electrodes. The cells were submitted to abuse tests such as shortcut or overcharge. A specific setup coupled with a mass spectrometer was developed to analyse in situ the gaseous emissions. All these points will be developed during the communication. References 1 A. Lewandowski et al., J Power Sources, 2009, 194, 601. 2 A. O. Diallo et al., Sep Purif Technol, 2012, 97, 228. 3 P. Wasserscheid and T. Welton, Ionic liquids in synthesis, Wiley-VCH, 2003. 4 L. Chancelier et al., in preparation. 5 L. Chancelier et al., Phys. Chem. Chem. Phys., accepted.
Due to environmental and energy concerns, batteries for electric vehicles are highly studied and ... more Due to environmental and energy concerns, batteries for electric vehicles are highly studied and developed. They are mainly based on lithium-ion technology, considered more efficient in terms of energy density. But carbonate mixtures used as electrolyte solvents could lead to safety issues, due to their high flammability and low flash points. Formulating electrolytes with negligible volatility and reduced flammability such as ionic liquids (ILs) could be safer. Ionic liquids have low vapour pressure, high flash point,1, 2 wide electrochemical window, good ionic conductivity and high decomposition temperature (Td).3But little information is available on their behaviour under abuse conditions, such as car crashes or any abnormal use (shortcut, overheat). From the literature, imidazolium and pyrrolidinium cations associated to bis(trifluoromethanesulfonyl)imide anion [NTf2] display the highest thermal stability4 (Figure 1, left) and the best performances as electrolyte solvents for lithium-ion batteries5,6,7. We investigated through several techniques (dynamic and long term TGA, …) the thermal decomposition of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C1C4Im][NTf2], 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide [PYR14][NTf2] and their corresponding lithium ion conductive electrolyte solutions, resulting from their mixture with 1 mol.L-1 of LiNTf2 ([C1C4Im][Li][NTf2] and [PYR14][Li][NTf2] respectively). Long term experiments (2 to 15 h at 350°C) revealed the highest thermal stability for imidazolium-based solutions. For both families, the major volatile decomposition products were identified as butene isomers. Recombined alkyl cations (e.g. C1Im, C4Im, C4C4Im and C1C1Im) were detected in the residual liquid phases, implying no mass loss during degradation. Flammability and heat of combustion were studied with a fire propagation apparatus (ISO12136). The solutions were found very weakly combustible (Figure 1, right), and LiNTf2 showed a flame retardant effect in the case of [PYR14][Li][NTf2]. Flammable gases were emitted due to cation decomposition, while toxic effluents result from the anion decomposition.8 [C1C4Im][Li][NTf2], [PYR14][Li][NTf2] and commercial carbonates were used as electrolytes in the batteries (coin cells and pouch cells), with Li4Ti5O12 and LiNi1/3Co1/3Mn1/3O2as negative and positive electrodes respectively. Batteries were submitted to cycling and overcharge. After any experiment, the gaseous phases of the batteries were analysed with a specific setup coupled with a mass spectrometer. References 1 A. Lewandowski et al., J Power Sources, 2009, 194, 601. 2 A. O. Diallo et al., Sep Purif Technol, 2012, 97, 228. 3 P. Wasserscheid and T. Welton, Ionic liquids in synthesis, Wiley-VCH, 2003. 4 L. Chancelier et al., in preparation. 5 D. R. MacFarlane et al., Energy &amp;amp; Environmental Science, 2013, 7, 232. 6 S. Seki et al., ECS Electrochemistry Letters,2012, 1, A77. 7 A. Balducci et al., J. Power Sources, 2011, 196, 9719. 8 L. Chancelier et al., Phys. Chem. Chem. Phys., 2014, 16, 1967.
As a novel class of solvents, ionic liquids have properties that make them promising key chemical... more As a novel class of solvents, ionic liquids have properties that make them promising key chemicals for the future bio-based economy. However, safety performance of ionic liquids relating physico-chemical hazards is very rarely investigated as they are often perceived as a non existing issue due to the status of ionic liquids in regulatory flammability hazard ranking systems. Limitations of conventional hazard rating in the case of ionic liquids lead to misleading statements pertaining physico-chemical hazards given the wide range of chemicals under interest (~10 18), while by contrast safety is of paramount importance as a goal in green chemistry principles. Thus, it becomes important to go beyond conventional hazard rating and therefore we promote the development of a dedicated methodology from hazard identification to contextual risk assessment, as illustrated in figure 1. For that purpose, work has been focused here to qualify fire hazard profiles of ionic liquids by use of both experimentation (oxygen bomb calorimetry, pyrolysis combustion flow calorimetry and fire propagation apparatus) and predictive tools using molecular modelling. The results of our study in particular provide: mutual support of these experimental methods, advanced pertinent knowledge on the actual fire hazards of ionic liquids, valuable data on heats and products released by such chemicals in fire conditions.
The theoretical (net) heat of combustion of materials is a basic information important for fire s... more The theoretical (net) heat of combustion of materials is a basic information important for fire safety studies. This paper is a review of existing methods ranging from use of tabulated data to calculations relying on more or less sophisticated engineering correlations based on the elemental compositions of materials and in some cases on their chemical structures. The presentation emphasises only those calculation methods that allow user-friendly estimations of the heats of combustion, that is to say when at most a simple datasheet processor is the only tool required. Empirical correlations developed in early times of combustion science by Dulong (France), Boie (Germany) and some others are examined here in the context of fire engineering. More recently proposed predictive methods of heats of combustion in fire or chemical engineering background, taking account of structural effects of the molecules on their heats of combustion are then presented and compared. Finally, consideration of the relevance and accuracy of the listed methods is provided and commented either by comparison of literature and calculated values, either by reference to measured data obtained by use of conventional oxygen bomb calorimetry.
Concern for the health of the natural environment is growing as human population grows. Recently,... more Concern for the health of the natural environment is growing as human population grows. Recently, renewed attention has been given to the environmental impact of fires and the fire implications of sustainability choices made in the built environment. To properly understand the environmental impact of fires, however, it is crucial that we can estimate fire emissions. This paper explores the concept of fire emissions and emission factors and investigates the potential to use small scale testing to develop emission factors for fire emissions. The findings show that there is a potential to use dynamic tests such as the cone calorimeter (CC, ISO 5660) and fire propagation apparatus (FPA, ISO 12136) to develop emission factors to estimate larger scale fire emissions, at least for CO and CO 2 emissions. While there is a spread of data from between the CC or FPA and the medium scale tests, this is of the same order or less than the spread between the two small scale tests. The spread in emission factor values from the various tests is smaller for CO 2 than for CO and greatest for small CO-emission factors (< 10 g/kg). More work is needed to similarly characterise a broad range of species.
There is no doubt that additive manufacturing (AM) technologies bring new and valuable assets to ... more There is no doubt that additive manufacturing (AM) technologies bring new and valuable assets to innovation: it makes possible to forge objects that were impossible to forge before, objects can be customized at will, etc. Jeremy Rifkin, an American economic and social theorist, even foresees in additive manufacturing technologies a looming third industrial revolution.
Due to environmental and energy concerns, batteries for electric vehicles are highly studied and ... more Due to environmental and energy concerns, batteries for electric vehicles are highly studied and developed. They are mainly based on lithium-ion technology, considered more efficient in energy density. Carbonate mixtures used as electrolyte solvents could lead to safety issues due to their high flammability and low flash points. Formulating electrolyte solutions with nonvolatile and nonflammable ionic liquids (ILs) instead of carbonate mixtures could be safer1 as they have low vapour pressure and high flash point.2 Moreover, they are good ionic conductors, present wide electrochemical window and high decomposition temperature (Td).3 But little information is available on their behaviour under abuse conditions like car crashes or any abnormal use (shortcut, overheat). In order to understand the possible decomposition mechanisms of ILs and their mixture with lithium salt during abuse tests, a thermodynamic study of these compounds was carried out. A critical literature study of the Td determined by thermogravimetric analysis (TGA) and consequent experiments highlighted the stability of the NTf2 anion combined with two cationic families: imidazolium and pyrrolidinium.4 We chose 1-butyl-3-methylimidazolium [C1C4Im] and 1-butyl-1-methylpyrrolidinium [PYR14] cations, bis(trifluoromethanesulfonyl)imide [NTf2] anion. The electrolytes were composed of their mixture with 1 mol.L-1 of LiNTf2 and referred to as [C1C4Im][Li][NTf2] and [PYR14][Li][NTf2]. Nevertheless, TGA does not give sufficient information on the nature of volatile emissions, so the thermal decomposition of [C1C4Im][NTf2] and [PYR14][NTf2] and their corresponding electrolytes was studied. Long term experiments with different techniques (2 to 15 h at 350°C) showed the highest stability of imidazolium-based solutions (Figure 1). For both families, the volatile decomposition products were mainly identified as butene isomers. Recombined alkyl cations (e.g. C1Im, C4Im, C4C4Im and C1C1Im) were detected in the residual liquid phases, implying that a degradation with no mass loss occurred. Figure 1: Long term stability test by TGA of IL-based electrolytes, neat ILs and lithium salt at 350 °C for 15 h Flammability and heat of combustion were studied with a fire propagation apparatus. The solutions were found very weakly combustible, and LiNTf2 showed a flame retardant effect. Flammable gases were emitted due to cation decomposition, and the anion decomposition formed toxic effluents.5 Figure 2: Heat release rate profiles of neat ILs and corresponding electrolytes showing good resistance to ignition (ca.5 min) Then the electrolytes [C1C4Im][Li][NTf2] and [PYR14][Li][NTf2] were used in batteries constituted of Li4Ti5O12 and LiNi1/3Co1/3Mn1/3O2 electrodes. The cells were submitted to abuse tests such as shortcut or overcharge. A specific setup coupled with a mass spectrometer was developed to analyse in situ the gaseous emissions. All these points will be developed during the communication. References 1 A. Lewandowski et al., J Power Sources, 2009, 194, 601. 2 A. O. Diallo et al., Sep Purif Technol, 2012, 97, 228. 3 P. Wasserscheid and T. Welton, Ionic liquids in synthesis, Wiley-VCH, 2003. 4 L. Chancelier et al., in preparation. 5 L. Chancelier et al., Phys. Chem. Chem. Phys., accepted.
Due to environmental and energy concerns, batteries for electric vehicles are highly studied and ... more Due to environmental and energy concerns, batteries for electric vehicles are highly studied and developed. They are mainly based on lithium-ion technology, considered more efficient in terms of energy density. But carbonate mixtures used as electrolyte solvents could lead to safety issues, due to their high flammability and low flash points. Formulating electrolytes with negligible volatility and reduced flammability such as ionic liquids (ILs) could be safer. Ionic liquids have low vapour pressure, high flash point,1, 2 wide electrochemical window, good ionic conductivity and high decomposition temperature (Td).3But little information is available on their behaviour under abuse conditions, such as car crashes or any abnormal use (shortcut, overheat). From the literature, imidazolium and pyrrolidinium cations associated to bis(trifluoromethanesulfonyl)imide anion [NTf2] display the highest thermal stability4 (Figure 1, left) and the best performances as electrolyte solvents for lithium-ion batteries5,6,7. We investigated through several techniques (dynamic and long term TGA, …) the thermal decomposition of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C1C4Im][NTf2], 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide [PYR14][NTf2] and their corresponding lithium ion conductive electrolyte solutions, resulting from their mixture with 1 mol.L-1 of LiNTf2 ([C1C4Im][Li][NTf2] and [PYR14][Li][NTf2] respectively). Long term experiments (2 to 15 h at 350°C) revealed the highest thermal stability for imidazolium-based solutions. For both families, the major volatile decomposition products were identified as butene isomers. Recombined alkyl cations (e.g. C1Im, C4Im, C4C4Im and C1C1Im) were detected in the residual liquid phases, implying no mass loss during degradation. Flammability and heat of combustion were studied with a fire propagation apparatus (ISO12136). The solutions were found very weakly combustible (Figure 1, right), and LiNTf2 showed a flame retardant effect in the case of [PYR14][Li][NTf2]. Flammable gases were emitted due to cation decomposition, while toxic effluents result from the anion decomposition.8 [C1C4Im][Li][NTf2], [PYR14][Li][NTf2] and commercial carbonates were used as electrolytes in the batteries (coin cells and pouch cells), with Li4Ti5O12 and LiNi1/3Co1/3Mn1/3O2as negative and positive electrodes respectively. Batteries were submitted to cycling and overcharge. After any experiment, the gaseous phases of the batteries were analysed with a specific setup coupled with a mass spectrometer. References 1 A. Lewandowski et al., J Power Sources, 2009, 194, 601. 2 A. O. Diallo et al., Sep Purif Technol, 2012, 97, 228. 3 P. Wasserscheid and T. Welton, Ionic liquids in synthesis, Wiley-VCH, 2003. 4 L. Chancelier et al., in preparation. 5 D. R. MacFarlane et al., Energy &amp;amp; Environmental Science, 2013, 7, 232. 6 S. Seki et al., ECS Electrochemistry Letters,2012, 1, A77. 7 A. Balducci et al., J. Power Sources, 2011, 196, 9719. 8 L. Chancelier et al., Phys. Chem. Chem. Phys., 2014, 16, 1967.
As a novel class of solvents, ionic liquids have properties that make them promising key chemical... more As a novel class of solvents, ionic liquids have properties that make them promising key chemicals for the future bio-based economy. However, safety performance of ionic liquids relating physico-chemical hazards is very rarely investigated as they are often perceived as a non existing issue due to the status of ionic liquids in regulatory flammability hazard ranking systems. Limitations of conventional hazard rating in the case of ionic liquids lead to misleading statements pertaining physico-chemical hazards given the wide range of chemicals under interest (~10 18), while by contrast safety is of paramount importance as a goal in green chemistry principles. Thus, it becomes important to go beyond conventional hazard rating and therefore we promote the development of a dedicated methodology from hazard identification to contextual risk assessment, as illustrated in figure 1. For that purpose, work has been focused here to qualify fire hazard profiles of ionic liquids by use of both experimentation (oxygen bomb calorimetry, pyrolysis combustion flow calorimetry and fire propagation apparatus) and predictive tools using molecular modelling. The results of our study in particular provide: mutual support of these experimental methods, advanced pertinent knowledge on the actual fire hazards of ionic liquids, valuable data on heats and products released by such chemicals in fire conditions.
The theoretical (net) heat of combustion of materials is a basic information important for fire s... more The theoretical (net) heat of combustion of materials is a basic information important for fire safety studies. This paper is a review of existing methods ranging from use of tabulated data to calculations relying on more or less sophisticated engineering correlations based on the elemental compositions of materials and in some cases on their chemical structures. The presentation emphasises only those calculation methods that allow user-friendly estimations of the heats of combustion, that is to say when at most a simple datasheet processor is the only tool required. Empirical correlations developed in early times of combustion science by Dulong (France), Boie (Germany) and some others are examined here in the context of fire engineering. More recently proposed predictive methods of heats of combustion in fire or chemical engineering background, taking account of structural effects of the molecules on their heats of combustion are then presented and compared. Finally, consideration of the relevance and accuracy of the listed methods is provided and commented either by comparison of literature and calculated values, either by reference to measured data obtained by use of conventional oxygen bomb calorimetry.
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Papers by GUY MARLAIR