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40 articles found

B3212 – Scale-up of Azide Chemistry: A Case Study

We report research and development conducted to enable the safe implementation of a highly enantioselective palladium-catalyzed desymmetrization of a meso–bis-ester using trimethylsilylazide (TMSN3) as the nucleophile. This work is used as a case example to discuss safe practices when considering the use of azide reagents or intermediates, with a focus on the thermodynamic and quantitative analysis of the hazards associated with hydrazoic acid (HN3).
Francisco Gonza?lez-Bobes, Nathaniel Kopp, Li Li, Joerg Deerberg, Praveen Sharma, Simon Leung, Merrill Davies, Joseph Bush, Jason Hamm, Michael Hrytsak, Org. Process Res. Dev. 2012, 16, 2051?2057

B2359 – A study of self-accelerating decomposition temperature (SADT) using reaction calorimetry

Self-accelerating decomposition temperature (SADT) is determined generally by one of four testing methods recommended by the UN orange book, and can be analytically and numerically evaluated by using the calorimetric results of ARC, Setaram C80D and other instruments. The SADTs evaluated by ARC must be under the assumption of zero order reaction kinetics, and require extrapolation to lower temperatures. Using the C80D, however, the reaction can easily be detected in the vicinity of the SADT for many reactive materials due to its higher sensitivity. Therefore, the SADTs evaluated are more accurate, especially for those reactive materials whose reaction mechanism, phase and so on change near the SADT. In the present study, the Setaram C80D and the ARC were used to investigate the decomposition of an asphalt–salts mixture, which had caused a fire in a nuclear fuel facility. The decomposition mechanism of this mixture was complex but the high sensitivity of the C80D enabled it to be elucidated, and a reasonable estimate of SADT was obtained. The estimated SADT from the ARC was about 70 K higher, due to the first two steps of the decomposition being undetected. In the estimation of SADT, the value of acquiring kinetic data close to the SADT can hardly be overstated
Jinhua Sun, Yongfu Li, Kazutoshi Hasegawa, Journal of Loss Prevention in the Process Industries 14 (2001) 331–336

B2357 – Cause analysis of the fire and explosion of asphalt–salt mixture in a nuclear wastes processing plant

In order to explain the detailed cause of the fire and explosion of asphalt–salt mixture (ASM) that happened at a nuclear wastes processing plant in Japan on March 11, 1997, a special experiment device was designed to prepare the ASM samples under different feeding rate of the waste and in different concentration of phosphate in the waste. The structure and diameter distribution of salt particles in the ASMs were examined by using a scanning electron microscope, the specific surface area of the salt particles was measured by the BET method, and the reactivity of ASMs was measured by using a heat flux calorimeter (C80). It was found that both the concentration of phosphate in the waste and the feeding rate of the waste have great influences on the structure of salt particles and the reactivity of the ASM. Most of the salt particles in the ASM are porous and have larger specific surface area when prepared at low feeding rate of the waste containing phosphate, which causes the ASM has lower onset temperature and self-accelerating decomposition temperature (SADT).
Jinhua Sun, Ping Lu, Kazutoshi Hasegawa, Fire Safety Journal 40 (2005) 411–424

B2302 – Spontaneous combustion identification of stored wet cotton using a C80 calorimeter

Many cotton fires were caused by spontaneous combustion, to identify the possible cause of such fires, a C80 microcalorimeter was employed in this paper. The cotton samples, dry or wetted, were sealed and heated from ambient temperature to 300 ?C at a 0.2 ?Cmin?1 heating rate. The result indicated that the dry cotton may not be the self-heating materials, but once it is wetted, its thermal stability is decreased with lower onset temperature and with larger heat generation, which can result to spontaneous combustion. It is speculated that microbiological degradation of cotton fibers has the potential to evolve methane and/or oxygen that in vapor phase could lead to spontaneous combustion. And therefore, it is confirmed that C80 can be used as an effective instrument to identify the cause of cotton spontaneous combustion fire
Wang Qingsong, Sun Jinhua, Guo Song, Industrial crops and products 2 8 ( 2 0 0 8 ) 268–272

B2197 – Explosion accident analysis of diaminodiphenolether process

Four workers were injured in an explosion accident, which was investigated. Based on outcomes of calorimeter experiments, at a temperature as low as 200°C, we observed that sodiumnitrophenol began to release heat, and its pressure increased to 8.7 bar quickly. We come to the conclusion that sodium nitrophenol adhering to the inside wall of the reactor was most likely the cause of the explosion.
H-C. Wu , Journal of Loss Prevention in the Process Industries 17 (2004) 373-376

B2191 – Isothermal reaction calorimetry as a tool for kinetic analysis

Reaction calorimetry has found widespread application for thermal and kinetic analysis of chemical reactions in the context of thermal process safety as well as process development. This paper reviews the most important reaction calorimetric principles (heat-flow, heat-balance, power-compensation, and Peltier principle) and their applications in commercial or scientific devices. The discussion focuses on the different dynamic behavior of the main calorimetric principles during an isothermal reaction measurement. Examples of available reaction calorimeters are further compared considering their detection limit, time constant as well as temperature range. In a second part, different evaluation methods for the isothermally measured calorimetric data are reviewed and discussed. The methods will be compared, focusing especially on the fact that reaction calorimetric data always contains additional informations not directly related to the actual chemical reaction such as heat of mixing, heat of phase-transfer/change processes or simple measurement errors. Depending on the evaluation method applied such disturbances have a significant influence on the calculated reaction enthalpies or rate constants.
A. Zogg, F. Stoessel, U. Fischer, K. Hungerbühler, Thermochimica Acta 419 (2004) 1-17

B2190 – Evaluation on thermal explosion induced by slightly exothermic interface reaction

An asphalt-salt mixture (ASM), which once caused a fire and explosion in a reprocessing plant, was prepared by imitating the real bituminization process of waste on a lab scale to evaluate its actual thermal hazards. Heat flux reaction calorimeters were used to measure the release of heat for the simulated ASM at a constant heating rate and at a constant temperature, respectively. Experimental results show that the reaction in the ASM below about 250°C is a slightly exothermic interface reaction between the asphalt and the salt particles contained in the asphalt, and that the heat release rate increases sharply above about 250°C due to melting of the salt particles. The reaction rates were formulated on the basis of an assumed reaction model, and the kinetic parameters were determined. Using the model with the kinetic parameters, temperature changes with time and drum-radius axes for the ASM-filled drum were numerically simulated assuming a one-dimensional infinite cylinder system, where the drum was being cooled at an ambient temperature of 50°C. The minimum filling temperature, at which the runaway reaction (MFTRR) can occur for the simulated ASM in the drum is about 194°C. Furthermore, a very good linear correlation exists between this MFTRR and the initial radius of salt particles formed in the bituminization product. The critical filling temperature to the runaway reaction is about 162°C for the asphalt-salt mixture, containing zero-size salt particles, filled in the same drum at an ambient temperature of 50°C. Thus, the runaway reaction will never occur in the drum filled with the asphalt-salt mixture under the conditions of the filling temperature below 162°C and a constant ambient temperature of 50°C. As a consequence, the ASM explosion occurred in the reprocessing plant likely was due to a slightly exothermically reaction and self heating.
M-H. Yu, Y-F. Li, J-H. Sun, K. Hasegawa, Journal of Hazardous Materials B113 (2004) 165-174

B2189 – Evaluation on thermal explosion induced by slightly exothermic interface reaction

An asphalt-salt mixture (ASM), which once caused a fire and explosion in a reprocessing plant, was prepared by imitating the real bituminization process of waste on a lab scale to evaluate its actual thermal hazards. Heat flux reaction calorimeters were used to measure the release of heat for the simulated ASM at a constant heating rate and at a constant temperature, respectively. Experimental results show that the reaction in the ASM below about 250°C is a slightly exothermic interface reaction between the asphalt and the salt particles contained in the asphalt, and that the heat release rate increases sharply above about 250°C due to melting of the salt particles. The reaction rates were formulated on the basis of an assumed reaction model, and the kinetic parameters were determined. Using the model with the kinetic parameters, temperature changes with time and drum-radius axes for the ASM-filled drum were numerically simulated assuming a one-dimensional infinite cylinder system, where the drum was being cooled at an ambient temperature of 50°C. The minimum filling temperature, at which the runaway reaction (MFTRR) can occur for the simulated ASM in the drum is about 194°C. Furthermore, a very good linear correlation exists between this MFTRR and the initial radius of salt particles formed in the bituminization product. The critical filling temperature to the runaway reaction is about 162°C for the asphalt-salt mixture, containing zero-size salt particles, filled in the same drum at an ambient temperature of 50°C. Thus, the runaway reaction will never occur in the drum filled with the asphalt-salt mixture under the conditions of the filling temperature below 162°C and a constant ambient temperature of 50°C. As a consequence, the ASM explosion occurred in the reprocessing plant likely was due to a slightly exothermically reaction and self heating.
M-H. Yu, Y-F. Li, J-H. Sun, K. Hasegawa, Journal of Hazardous Materials B113 (2004) 165-174

B2141 – Nitrobenzene and aniline caused fire and explosion: a case study

A great fire accident occurred at November 13, 2005, in Jilin, China caused at least 8 deaths, 60 injured and the pollution of Songhua River. This accident is primarily thought was caused by jam and improper operation in simply word. In order to investigate the inherent causes, a C80 calorimeter was used to study the thermal runaway of nitrobenzene, mixtures of nitrobenzene with acids and aniline. The chemical reaction kinetic parameters such as reaction order, activation energy and frequency factor were calculated based on C80 experimental data. Based on these parameters and the thermal runaway models, the self-accelerating decomposition temperature (SADT) of mixtures of nitrobenzene with acids and aniline were calculated. The results show that nitrobenzene is stable, but its mixtures with acids are unstable, and then, the inherent cause of the fire is attributing to the self heating process of nitrobenzene mixtures with acids. In this fire accident, when the feeding of unrefined nitrobenzene was jammed in pipe, the self heating was undergoing, as the generated heat was not loss to the surrounding instead of to heat the nitrobenzene mixtures, and then the thermal runaway of the unrefined materials turned into fire at last.
Q. Wang, S. Guo, J. Sun, H. Ding and T. Wang, IChemE Symposium Series NO. 153, Conf. Loss Prevention

B2064 – Thermal characteristics of lysine tri-isocyanate and its mixture with water

The thermal reactivity of lysine tri-isocyanate (LTI, 2-isocyanatoethyl-2,6-diisocyanato caproylate) and its mixture with1%waterwas investigated after the occurrence of a runaway reaction at a plant. By using a sensitive thermal calorimeter, C80, and an adiabatic calorimeter, ARC, an onset reaction of LTI was observed at 70-100°C and it became vigorous at 175-200°C. The reaction is considered as co-polymerization at this stage, which causes a second decomposition reaction at 200°C if the heat generation is accumulated in the vessel. On the other hand, the presence of water can catalyze LTI at much lower onset temperature and lead to a moderate reaction at 50°C since carbamine is produced and in turn it induces decarbonization of the LTI molecule with significant release of CO2 gas which was detected by a gas chromatography and an FT-IR gas analyzer.
X-R. Li, H. Koseki, Y. Iwata, Journal of Hazardous Materials 142 (2007) 647-652

B1868 – DRC signal treatment for heat flow and reagents accumulation determination

In order to optimize the use of the DRCw data (Differential Reaction Calorimeter commercialized by Setaram SA), Aventis Pharma Safety Laboratories and the Thermokinetic team of Nice Sophia-Antipolis University have developed a software which deconvolutes collected DRC data to assess the real heat flow and determine reagents accumulation. The accuracy of the results given by the DRC is shown for three batch reactions (neutralization, hydrolysis and acylation). The results are very close to those obtained by RC1 online heat flow measurements.
H. Nogent, X. Le Tacon, L. Vincent, N. Sbirrazzuoli, Journal of Loss Prevention in the Process Industries 18 (2005) 43-48

B1867 – Heat generation of refuse derived fuel with water

In order to clarify the scenario of fires and accidents resulting from spontaneous combustion of Refuse Derived Fuel (RDF), exothermic phenomenon of RDF with water at ambient temperature was characterized by Calvet calorimeter (C 80 and MS 80), Thermal Activity Monitor and Dewar. The spontaneous combustion characteristic of RDF without additional water was examined by Thermogravimetry and Differential Thermal Analysis and Spontaneous Ignition Tester. The experimental results show the heat generation of RDF with different water content occurred instantly after additional water was added into RDF, while no exothermic phenomenon can be observed if no additional water was added into RDF at room temperature. It means that the self-heating of RDF does not only result from fermentation of RDF because of the prompt heat generation and temperature rise of RDF with water. It is possible that the self-heating of RDF results from heat of wetting first when additional water/vapor is absorbed by RDF. The further quantitative analysis for the self-heating of RDF with water/vapor should be made to explain the process of spontaneous combustion of RDF in detail.
Z-M. Fu, X-R. Li, H. Koseki, Journal of Loss Prevention in the Process Industries 18 (2005) 27-33

B1818 – Experimental determination of the minimum onset temperature of runaway reaction from a radioactive salt disposal in asphalt

In order to clarify the reason for the most hazardous explosion in the history of the Japanese nuclear power development by a radioactive salt disposal in asphalt, an adiabatic process was developed using a Dewar vessel to minimize the temperature difference between the reactants and the surroundings. By this means, the heat evolution from a reaction which is readily lost can be detected at a lower temperature imitating the accidental condition. A series of ambient temperature-tracking Dewar experiments on asphalt salt mixtures were conducted under different initial ambient temperatures, such as 230, 210, 190, and 170°C, respectively. As a result, it was observed that from 190°C the sample's temperature rose until a runaway reaction occurred. The minimum onset temperature for the runaway reaction of the asphalt salt mixture was determined to be 190°C, which is close to the initial temperature of approximately 180°C, the same temperature as the real accident. This implies that at near this operational temperature, initial faint chemical reactions may occur and lead to further rapid reactions if heat is accumulated at this stage.
X-R. Li, J-H. Sun, H. Koseki, K. Hasegawa, Journal of Hazardous Materials A120 (2005) 51-56

B1774 – Cause analysis of the fire and explosion of asphalt-salt mixture in a nuclear wastes processing plant

In order to explain the detailed cause of the fire and explosion of asphalt-salt mixture (ASM) that happened at a nuclear wastes processing plant in Japan on March 11, 1997, a special experiment device was designed to prepare the ASM samples under different feeding rate of the waste and in different concentration of phosphate in the waste. The structure and diameter distribution of salt particles in the ASMs were examined by using a scanning electron microscope, the specific surface area of the salt particles was measured by the BET method, and the reactivity of ASMs was measured by using a heat flux calorimeter (C80). It was found that both the concentration of phosphate in the waste and the feeding rate of the waste have great influences on the structure of salt particles and the reactivity of the ASM. Most of the salt particles in the ASM are porous and have larger specific surface area when prepared at low feeding rate of the waste containing phosphate, which causes the ASM has lower onset temperature and self-accelerating decomposition temperature (SADT).
J. Sun, P. Lu, K. Hasegawa, Fire Safety Journal 40 (2005) 411-424

B1728 – A reaction calorimeter and calorimetric tools for safety testing on a laboratory scale

Calorimetry combined with thermal analysis is an essential tool for the evaluation of thermal risks linked with chemical reactions at industrial scale. The energies of synthesis reactions or decomposition reactions as well as the heat capacities of reaction masses can be measured using such techniques. The capacity of the SETARAM differential reaction calorimeter (DRC) to determine essential safety data has been demonstrated with the measurement of heat capacities of cyclohexane and propanoic acid. Results of an industrial reaction are also presented.
R. André, M. Giordano, C. Mathonat, R. Naumann, Thermochimica Acta 405 (2003) 43-50

B1699 – Thermal decomposition kinetic of reactive solids based on isothermal calorimetry measurements

An isothermal method was applied to measure the thermal decomposition of reactive solids in a sensitive heat flux reaction calorimeter, C80. This technique experimentally clarified the decomposition mechanisms of unstable substances based on the shapes of the heat flow curves, from which autocatalysis, first-order reaction or pseudo-autocatalytic reaction could be recognized. Kinetic parameters were derived from the measured data.
X-R. Li and H. Koseki, Journal of Thermal Analysis and Calorimetry 85 (2006) 637-642

B1657 – Evaluation of microcalorimetric measurements in terms of information content for decomposition reactions

Decomposition reactions of liquids and solids can be observed by the heat development using microcalorimetric methods. By determination of the released heat flow for heating up a sample, it is possible to get details to answer safety relevant questions. For reactions nth order the overall activation energy and the accompanying frequency factor can be determined, provided that the heat release is determined by the rate of a single reaction step. Researches have been carried out whether these parameters are useable for safety technical specifications. Autocatalytic affected decomposition reactions are connected with special problems. This affects the experimental examination or interpretation of results, and also the precise identification of beginning decomposition reactions in technical reactors. The application of microcalorimetric measurements on decomposition reactions is described and associated problems are pointed out. The conclusions from thermoanalysis data alone are not sufficient in the final consequence for safety technical assessments.
S. Fischer, G. Krahn and B. Reimer, Thermochimica Acta 445 (2006) 160-167

B1646 – Investigation on spontaneous ignition of two kinds of organic material with water

A systematic investigation was performed to elucidate the cause of spontaneous ignition of Refuse Derived Fuel (RDF) and Meat Bone Meal (MBM). Heat generation in both RDF and MBM with addition of water liquid and vapor at room temperature was determined by isothermal calorimetry. Compared with water liquid, the heat of wetting by sorption of water vapor at 80% relative humidity and 25°C was larger, which can raise the temperature of RDF and MBM more than 30 and 56°C, respectively. Heat generation due to fermentation occurred and the temperature of RDF and MBM reached or exceeded 80°C after 5 days for RDF and 4 days for MBM at 100% RH. The spontaneous ignition for RDF and MBM results from heat of wetting and fermentation at room temperature and a further exothermic reaction at higher temperature.
Z-M. Fu, H. Koseki and Y. Iwata, Thermochimica Acta 440 (2006) 68-74

B1622 – Thermal decomposition of polymeric aminoborane (H2BNH2)x under hydrogen release

Polymeric aminoborane (H2BNH2)x has been isolated during the thermal decomposition of solid borazane H3BNH3 at temperatures below 370 K. Polymeric aminoborane is a white noncrystalline solid, stable at room temperature and up to 380 K. In the temperature range of 380-500 K polymeric aminoborane undergoes a thermal decomposition, which was studied by differential scanning calorimetry (DSC), by thermogravimetry (TG) and by volumetric measurements. The solid residue was characterized by IR spectroscopy, by powder X-ray diffraction (XRD) analysis and by solid state 11B NMR spectroscopy. The thermal decomposition of polymeric aminoborane (H2BNH2)x is an exothermic process accompanied by evolution of nearly 1 mol hydrogen per mole H2BNH2 unit corresponding to the volumetric measurements. The detected mass loss of the solid phase indicates the formation of further gaseous products beside hydrogen. The final mass loss increases with rising heating rate, in contrast to the final amount of evolved hydrogen, which still remains constant.
J. Baumann, F. Baitalow and G. Wolf, Thermochimica Acta 430 (2005) 9-14

B1571 – Advanced kinetic tools for the evaluation of decomposition reactions

An advanced kinetic study on the thermal behaviour of pyrotechnic ignition mixtures has been carried out by differential scanning calorimetry using different B/KNO3 mixtures (50:50, 30:70, 20:80) as a model reaction. The experimental conditions applied (isochoric conditions/closed crucibles and isobaric conditions/open crucibles) as well as the composition of the mixtures noticeably influences the relative thermal stabilities of the energetic materials. The kinetic study focused on the prediction of the thermal stability of the different mixtures both in extended temperature ranges and under temperature conditions at which ordinary investigation would be very difficult. Using advanced numerical tools [1], thermal ageing and influence of the complex thermal environment on the heat accumulation conditions were computed. This can be done for any surrounding temperature profile such as isothermal, non-isothermal, stepwise, modulated, shock, adiabatic conditions and additionally for temperature profiles reflecting real atmospheric temperature changes (yearly temperature profiles of different climates with daily minimal and maximal fluctuations). Applications of accurate decomposition kinetics enabled the determination of the time to maximum rate under adiabatic conditions (TMRad) with a precision given by the confidence interval of the predictions. This analysis can then be applied for the examination of the effects of the surrounding temperature for safe storage or transportation conditions (e.g. determination of the safe transport or storage temperatures).
B. Roduit, Ch. Borgeat, B. Berger, P. Folly, B. Alonso, J.N. Aechicher, F. Stoessel, Journal of Thermal Analysis and Calorimetry 80 (2005) 229-236

B1570 – The prediction of thermal stability of self-reactive chemicals : from milligrams to tons

An advanced study on the thermal behaviour of double base (boost and sustain propellant) rocket motor used in a ground to air missile has been carried out by differential scanning calorimetry (DSC). The presence of two propellants as well as the different experimental conditions (open vs. closed crucibles) influence the relative thermal stability of the energetic materials. Several methods have been presented for predictions of the reaction progress of exothermic reactions under adiabatic conditions. However, because decomposition reactions usually have a multi-step nature, the accurate determination of the kinetic characteristics strongly influences the ability to correctly describe the progress of the reaction. For self-heating reactions, incorrect kinetic description of the process is usually the main source of serious errors for the determination of the time to maximum rate under adiabatic conditions (TMRad). It is hazardous to develop safety predictive models that are based on simplified kinetics determined by thermoanalytical methods. Applications of finite element analysis (FEA) and accurate kinetic description allow determination of the effect of scale, geometry, heat transfer, thermal conductivity and ambient temperature on the heat accumulation conditions. Due to limited thermal conductivity, a progressive temperature increase in the sample can easily take place resulting in a thermal explosion. Use of both, kinetics and FEA [1], enables the determination of the reaction progress and temperature profiles in storage containers. The reaction progress and temperature can be determined quantitatively at every point in time and in space. This information is essential for the design of containers of self-reactive chemicals, cooling systems and the measures to be taken in the event of a cooling failure.
B. Roduit, Ch. Borgeat, B. Berger, P. Folly, B. Alonso, J.N. Aechicher, Journal of Thermal Analysis and Calorimetry 80 (2005) 91-102

B1523 – Hazard evaluation of self-decomposition materials by the combination of pressure and heat flux measurements

Thermal decomposition of unstable chemicals is always accompanied by heat release and gas generation. To ascertain such relationship, a heat flux calorimeter C80D fitted with a pressure-sensitive transducer provided simultaneous knowledge about pressure and heat flux behavior of a reactive agent. Consequently, (dP/dt)max was a parameter to reflect the characteristics of gas production potential during decomposition with the rate of reaction, which can be determined by thermal data, and was considered as a criterion to evaluate the hazardous characteristics for unstable substance. The results were compared with those in the UN standard PVT tests and the modified closed pressure vessel test (MCPVT), which have intense outer heating. It indicates that the decomposition measured in the C80D represents the inherent factor of materials and rate of reaction is the dominant factor to contribute to the intensity of the decomposition in other PVTs.
X-R. Li, H. Koseki, Thermochimica Acta 423 (2004) 77-82

B1486 – Thermal hazard evaluation of complex reactive substance using calorimeters and dewar vessel

In this paper, several small-scale screening test methods were discussed on evaluating the thermal hazard of reactive substances. Generally the sensitivities of DSC and ARC are not high enough to evaluate the thermal hazards for all reactive substance, especially, for those of complex reactions containing a phase and/or chemical reaction mechanism change in the lower temperature range. Using the C80, however, the reaction can easily be detected in the lower temperature range due to its high sensitivity. Therefore, the C80 gives generally more accurate results than DSC and ARC. Data from C80 and Dewar vessel were compared and it indicates that the Dewar vessel has also high enough sensitivity to evaluate the thermal hazard and determine the heat flux in lower temperature range of reactive substances.
J.H. Sun, X.R. Li, K. Hasegawa, G.X. Liao, Journal of Thermal Analysis and Calorimetry 76 (2004) 883-893

B1399 – The construction and evaluation of a high pressure manifold and vessels for a Calvet type microcalorimeter

A Setaram C-80 calorimeter has been modified in order to measure the heat flow of energetic materials at pressures up to 69 MPa. A manifold and sample cells capable of operating at high pressure were designed, constructed and evaluated. This paper will describe, in detail, the high pressure manifold construction, safety assessment and calibration. As well, the results for initial trials with ammonium nitrate (AN), and pentaerythritol tetranitrate (PETN) at various pressures and heating rates will be discussed.
D.E.G. Jones, A-M. Turcotte, R.C. Fouchard, Thermochimica Acta 401 (2003) 63-75

B1374 – Fast determination of thermodynamic data

R. André, L. Bou Diab, F. Stoessel, M. Giordano, C. Mathonat CPP 3 (2002 ) 46-47

B1362 – A new reaction calorimeter for screening purposes during process development

Calorimetry, in combination with thermal analysis, is an essential tool for a data-based assessment of thermal risks linked with the performance of chemical reactions at industrial scale. The energies of synthesis reactions or of decomposition reaction as well as the heat capacities of reaction masses can be measured by these techniques. The performance of the differential reaction calorimeter (DRC) from SETARAM in the determination of essential safety data was demonstrated using two example reactions. The differential reaction calorimeter was found to be a powerful screening tool in an organic synthesis laboratory or in a development laboratory, and it is especially well suited for a fast and low-cost determination of the thermal parameters of chemical reactions, even when only a few raw materials are available.
R. André, L. Bou-Diab, P. Lerena, F. Stoessel, M. Giordano, C.Mathonat, Organic Process Research & Development 6 (2002) 915-921

B1333 – A new reaction calorimeter and calorimetric tools for safety testing at laboratory scale

One way of obtaining essential data about temperature, pressure and energy used to establish thermal runaway diagram, is the experimental determination by thermal analysis and calorimetry. Four main kinds of equipment can be used in a Safety Testing Laboratory: Differential Scanning Calorimeters (DSC), Calvet calorimeters, calorimetric reactors, adiabatic calorimeters. Recently, SETARAM has commercialized a new reaction calorimeter. This calorimeter, has been developed in collaboration with Aventis and their Security laboratory in Neuville S/Saône. A study that was done at the Swiss Institute of Safety will be presented. Two reactions have been studied: in isothermal batch and semi-batch operation.
R. André, L. Bou-Diab, F. Stoessel, Setaram News n°7

B1318 – Study on the explosion of run-away reaction triggered by a faint heat generation

J. Sun, X. Li, W.Tang and K. Hasegawa, 10th Loss prevention and safety (2001) 853-866

B1136 – Choise of runaway reaction scenarios for vent sizing based on pseudo adiabatic calorimetric techniques.

J-L. Gustin / 552/97/688 GUS/cle

B1135 – Runaway reaction hazards in processing organic nitro compounds.

Pure organic nitro compounds, i.e., aromatic or aliphatic nitro compounds, decompose at high temperatures, exhibiting large decomposition exotherms. In most cases, the decomposition is violent or explosive. In practical process situations, nitro compounds are mixed with other chemicals or contaminated by impurities which lower their thermal stability. Contaminated nitro compounds or solutions of nitro compounds may decompose at much lower temperatures than the pure products. Their decomposition is less rapid but remains highly exothermic. Therefore, for practical reasons, the most relevant information in the field of process safety is to describe how reactants, solvents, and impurities may affect the organic nitro compounds' thermal stability and in which process situations this may be a hazard.
J-L. Gustin, Organic Process Research & Development 2 (1998) 27-33

B1089 – Oscillating processes during thermal decomposition of aluminiumhydroxide chloride gels.

DTA-, DSC-, and DTG-diagrams of aluminiumhydroxide chloride gels show numerous sharp and often rather regular oscillations, caused by endothermal decomposition and exothermal crystallisation subprocesses in the temperature range between 550 and 600°C. In this range the formation of alpha-Al2O3, corundum, is observed. It is assumed, that the oscillations are produced by the periodic formation of dense layers of an intermediate phase, which act as diffusion barriers for the decomposition gas, and the crystallisation of these layers into corundum, connected with a reduction of transportation hindrance of the gas molecules. These processes are considered in their feedback with the decomposition reaction, by which the intermediate phase is formed.
P. Brand, C. Günther, G. Wolf, Thermochimica Acta 290 (1996) 109-114

B0827 – A computerized system for research into the thermal safety of chemical processes

Ensuring the thermal safety of chemical processes is an important practical problem because of the possible development of thermal explosion caused by the heat evolved during the chemical processes. A computerized system developed for solving this complicated problem is described, based on the range of Setaram thermoanalytical and calorimetric devices. The structure, purpose and possibilities of the system are considered. Methodological questions of kinetic experiments, kinetic analysis, thermal explosion simulation and organization of software are also discussed.
A.A. Kossoy, A.I. Benin, P.Yu. Smykalov and A.N. Kasakov, Thermochimica Acta 203 (1992) 77-92

B0702 – Automated system of kinetic researches in thermal analysis. I. General description of automated system.

Kinetic research with employment of thermal analysis methods comprises a complicated multi-stage procedure. The full performance is impossible to be achieved without automation of all the stages with regard to their interconnections. Development of the automated system for kinetic research (ASKR) in thermal analysis is the solution to this problem. ASKR is described as based on the complex of thermoanalytical devices of the 'SETARAM' company. The system allows reducing the time of measurements and ensures high quality and reliable results. The structure, purpose and potentialities of ASKR are considered, methodological questions of kinetic experiments and kinetic data analysis, organisation of software are also discussed in the paper.
A.I. Benin, A.A. Kossoy and P.U. Smykalov, Journal of Thermal Analysis 38 (1992) 1151-1165

B0701 – Automated system of kinetic researches in thermal analysis. II. Organization of kinetic experiment in ASKR.

The correctness of a kinetic experiment is an essential condition for obtaining reliable results in kinetic investigations. Methods for provision and testing of thermo-physical and concentration correctness are discussed in the presen~t~article. Problems connected with the non-isothermal mode of an actual thermoanalytical experiment caused both by programming and by heat release in the sample are considered. Application analysis of the combined partiallinear heating laws in kinetic investigations is given in relation to the heat flux calorimeters 'SETARAM'.
A.I. Benin, A.A. Kossoy and F.Yu. Sharikov, Journal of Thermal Analysis 38 (1992) 1167-1180

A1395 – Mechanism of thermal decomposition of a pesticide for safety concerns: Case of Mancozeb

Thermal decomposition under both air and inert atmospheres of a commercial Mancozeb product was investigated through thermogravimetric analysis and laboratory scale thermal treatment from 20 ?C to 950 ?C, with analysis of gaseous and solid products. The aim of this study is the understanding of the thermal degradation mechanisms of a pesticide under different atmospheres and the chemical identification of the solid and gaseous pollutants which can be emitted during warehouse fires and which can constitute a threat for health and environment. Pyrolysis of Mancozeb takes place between 20 ?C and 950 ?C and lead essentially to CS2 and H2S emissions with formation at 950 ?C of MnS and ZnS. Thermal oxidation of Mancozeb under air occurs between 150 ?C and 950 ?C with formation of CO, CO2 and sulphur gases (CS2 and SO2). The first step (155–226 ?C) is the loss of CS2 and the formation of ethylene thiourea, ZnS and MnS. The metallic sulphides are oxidized in ZnO and MnSO4 between 226 ?C and 650 ?C (steps 2 and 3). MnSO4 is then oxidized in Mn3O4 during the last step (step 4) between 650 ?C and 950 ?C. At 950 ?C, carbon recovery is close to 95%. Sulphur recovery is close to 98% with an equal partition between SO2 and CS2.
N. Giroud, S. Dorge, G. Trouvé, Journal of Hazardous Materials 184 (2010) 6–15

A1060 – Synthetic hydromagnesite as flame retardant. Evaluation of the flame behaviour in a polyethylene matrix

Synthetic hydromagnesite obtained from an industrial by-product was evaluated as a non-halogenated flame retardant. It was used in combination with aluminium hydroxide (ATH) and compared with commercial flame retardants like magnesium hydroxide (MH) and natural hydromagnesite-huntite (U) in a polyolefin system of low-density polyethylene/poly(ethylene-co-vinyl acetate) (LDPE/EVA). The thermal stability and flame behaviour of the halogen free flame retarded composites were studied by thermogravimetric and differential thermal analysis (TG-DTA), limiting oxygen index (LOI), epiradiateur and cone calorimeter. It has been shown that synthetic hydromagnesite could be an alternative solution to the use of MH in non-halogenated flame retardant systems in EVA.
L. Haurie, A.I. Fernandez, J.I. Velasco, J.M. Chimenos, J-M. Lopez Cuesta, F. Espiell, Polymer Degradation and Stability 91 (2006) 989-994

A1037 – Thermal stability and flammability of silicone polymer composites

Silicone polymer composites filled with mica, glass frit, ferric oxide and/or a combination of these were developed as part of a ceramifiable polymer range for electrical power cables and other high temperature applications. This paper reports on the thermal stability of polymer composites as determined by thermogravimetric techniques, thermal conductivity and heat release rate as measured by cone calorimetry. The effects of fillers on thermal stability and flammability of silicone polymer are investigated. Of the fillers studied, mica and ferric oxide were found to have a stabilising effect on the thermal stability of silicone polymer. Additionally, mica and ferric oxide were found to lower heat release rates during combustion, but only mica was found to increase time to ignition.
L.G. Hanu, G.P. Simon, Y-B. Cheng, Polymer Degradation and Stability 91 (2006) 1373-1379

A0666 – Intumescent fire protective coating: Toward a better understanding of their mechanism of action

The aim of this work is to better understand the role and the mechanism of action of boric acid and of coated ammonium polyphosphate (pure ammonium polyphosphate coated with THEIC) used as flame retardants in a commercial intumescent epoxy-based formulation using analytical techniques including thermogravimetric analyses (TGA) and solid-state NMR. In a previous paper, we detected that some reactions took place during the intumescence phenomenon between boric acid and ammonium polyphosphate upon heating. The paper focuses on the analysis of the degradation of those sole components and on the study of their interaction. It is first shown that the THEIC increases the thermal degradation rate of ammonium polyphosphate. This enables the degradation products of boric acid and coated ammonium polyphosphate to react together, resulting in the formation of borophosphate. It is suggested that the formation of this product provides the superior mechanical resistance of the char and promotes the adhesion of char on the steel plate.
M. Jimenez, S. Duquesne, S. Bourbigot, Thermochimica Acta 449 (2006) 16-26

A0650 – Influence of nano-LDHs on char formation and fire-resistant properties of flame-retardant coating

Flame-retardant nano-coatings were prepared by adding flame-retardant nano-concentrates to APP/PER/EN coating. Dispersion morphology and stability principle of nano-size magnesium aluminum-layered double hydroxides (nano-LDHs) have been studied by using transmission electron microscopy (TEM). Relation of added amount of nano-concentrates in flame-retardant coating to flame-retardant properties for APP/PER/EN system has been studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), differential thermal analysis (DTA), thermogravimetry (TG) and fire protection test. It was indicated that nano-LDHs could catalyze the esterification reaction between ammonium polyphosphate and pentaerythritol, and IPN network formed by nano-size thermal-decomposed products of LDH could efficiently enhance char formation and structure of char layer. Only specific content (1.5%) of nano-LDHs in flame-retardant coating could efficiently improve its char layer structure and fire-resistant properties. Nano-LDHs (1.5%) greatly improve mechanical properties (bonding strength, bending resistance and resistance to freeze-thaw cycle) of flame-retardant coating.
Z. Wang, E. Han, W. Ke, Progress in Organic Coatings 53 (2005) 29-37

A0631 – Influence of talc physical properties on the fire retarding behaviour of (ethyleneevinyl acetate copolymer/magnesium hydroxide/talc) composites

The present work focuses on the fire retarding behaviour of (ethyleneevinyl acetate (EVA) copolymer/magnesium hydroxide (MH)/talc) composites. Talc particles of different lamellarity and specific surface area have been tested, leading to the conclusion that for highly lamellar talc particles, the fire retarding behaviour becomes similar to that of (EVA/MH/organomodified montmorillonite (oMMT)) composites, with a significant intumescence. This intumescence, which occurs during the pre-ignition period in cone calorimeter tests, seems to be related to three phenomena caused by the presence of the lamellar particles (oMMT or talc): heterogeneous bubble nucleation, increased viscosity and charring promotion.
L. Clerc, L. Ferry, E. Leroy, J-M. Lopez-Cuesta, Polymer Degradation and Stability 88 (2005) 504e511