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Estimation of Time to Maximum Rate under Adiabatic Conditions (TMR ad ) Using Kinetic Parameters Derived from DSC - Investigation of Thermal Behavior of 3-methyl-4-nitrophenol. APSS 2009 20-23 October, 2009, Osaka, Japan.
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Estimation of Time to Maximum Rate under Adiabatic Conditions (TMRad) Using Kinetic Parameters Derived from DSC - Investigation of Thermal Behavior of 3-methyl-4-nitrophenol APSS 2009 20-23 October, 2009, Osaka, Japan Bertrand Roduit1, Franz Brogli2, Francesco Mascarello3, Mischa Schwaninger3, Thomas Glarner4, Jacques Wiss5, Markus Luginbühl6, Craig Williams6, Pierre Reuse7 1AKTS AG Advanced Kinetics and Technology Solutions, TECHNOArk 1, 3960 Siders, Switzerland 2Ciba Schweizerhalle AG, P.O. Box, CH-4002 Basel, Switzerland 3DSM Nutritional Products Ltd., Safety laboratory, 4334 Sisseln, Switzerland 4F. Hoffmann-La Roche Ltd, Safety laboratories, 4070 Basel, Switzerland 5Novartis Pharma AG, Novartis Campus, WSJ-145.8.54, 4002 Basel, Switzerland 6Syngenta Crop Protection Münchwilen AG, WMU 3120.1.54, 4333 Münchwilen, Switzerland 7Swiss Safety Institute, Schwarzwaldallee 215, WRO-1055.5.02, 4002 Basel, Switzerland www.akts.com
Adiabatic Runaway Scenario Example of adiabatic runaway scenario Before :
Adiabatic Runaway Scenario Example of adiabatic runaway scenario After :
Analysis Samples • Analysis samples: 3-methyl-4-nitrophenol • CAS No: 2581-34-2 • Objective: Determine the initial temperature for Time To Maximum Rate under adiabatic conditions TMRad = 24h - Different suppliers (different batches) - DSC or ARC techniques were applied - Different DSC apparatus (various manufacturers)
3-methyl-4-nitrophenol at 4 K/min Typical DSC trace of 3-methyl-4-nitrophenol recorded at 4 K/min and sigmoid baseline construction.
Reproducibility of the DSC traces The reaction rates for all samples at 4K/min. Despite of the different experimental setups and sample origins the reproducibility of the DSC traces is acceptable.
Differential isoconversional method 2 2 1 3 3 = ln Theory: isoconversional analysis & baseline optimization
Reactions rate and progress: Non-isothermal Reaction rates da/dt and progresses a corresponding to the normalized DSC-signals for the decomposition of all 3-methyl-4-nitrophenol samples under non-isothermal conditions. The values of the heating rates are marked on the curves. The comparison of the experimental and simulated signals at chosen experimental conditions is shown in the respective insets.
Reactions rate and progress: Isothermal Reaction rates da/dt and progresses a corresponding to the normalized DSC-signals for the decomposition of all 3-methyl-4-nitrophenol samples under isothermal conditions. The values of the temperatures are marked on the curves. The comparison of the experimental and simulated signals at chosen experimental conditions is shown in the respective insets.
Experimental Validation Isothermal validation • ARC validation • Initial temperature for TMRad 24h = ? °C
Link between kinetics and TMRad Or = =0 Determination of time to maximum rate under adiabatic conditions (TMRad) Adiabatic Conditions From DSC =1 =DTad > 1000 kg Theory
Key parameters in adiabatic experiments DTadiabatic Determination of time to maximum rate under adiabatic conditions (TMRad) Key parameters obtained from adiabatic experiments Temperature profile of an adiabatic runaway reaction, Temperature /°C =1 =DTad Time /h Theory
Key parameters in adiabatic experiments DTadiabatic Time to Maximum Rateadiabatic Maximum Selfheat rate Determination of time to maximum rate under adiabatic conditions (TMRad) Key parameters obtained from adiabatic experiments Temperature profile of an adiabatic runaway reaction, corresponding self-heating rate Temperature /°C Selfheat rate /°C/min =1 =DTad Time /h Theory
Experimental Validation Typical ARC test for 3-methyl-4-nitrophenol carried out in HWS mode. Having the kinetic description of the reaction rate from the DSC data, one can estimate that the reaction progress a after ca. 11.3 h of HWS testing amounts to about 0.0095 (ca. 1%). From the time at which the temperature of the detection limit (183.81°C) was reached the value of TMR amounts to ca. 4.4h (15.67-11.29h). Solid line depicts the simulation being in a good agreement with the experimental HWS-ARC data presented as symbols.
Experimental Validation Isothermal validation ARC validation • Initial temperature for TMRad 24h = ? °C (F =1)
TMRad 24 h Summary of the results of determination of the initial temperatures leading to TMRad = 24 h with AKTS-Thermokinetics Software by using all DSC data collected in round robin test. Mean value for TMRad 24h = 151.27 ±3.01°C
Experimental Validation Isothermal validation ARC validation Initial temperature for TMRad 24h = 151°C (F =1)
Conclusion ‘Safety through calculations not by accidents’ The correct determination of TMRad based on DSC data requires two important parameters (i) an advanced kinetics of the investigated reaction and (ii) an adiabatic heat balance of the system.
AdvancedKinetics and TechnologySolutions Acknowledgements Our partners and friends AKTS AG, C. Borgeat, C. Luyet, L.Xia, N. Solioz, JG. Pont armasuisse, Dr. P. Folly, Dr. A.Sarbach and B. Berger Swiss Federal office of Public Health, Dr. V. Dudler Univ. of Western Switzerland, Prof. J.N. Aebischer, S. Gomez, B. Alonso Swiss Institute of Safety and Security, Dr. P. Reuse, Prof. F. Stoessel, Dr. H. Fierz Nitrochemie Wimmis AG, Dr. M. Ramin, Dr. U. Schädeli, Dr. B. Vogelsanger
