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
1
Adiabatic Runaway Scenario
Example of adiabatic runaway scenario
Before :
2
Adiabatic Runaway Scenario
Example of adiabatic runaway scenario
After :
3
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)
4
3-methyl-4-nitrophenol at 4 K/min
5
Exo
Heat : -2,194.016 (J/g)
T : 198.92 and 344.13 (°C)
Top of Peak : 294.34 (°C)
Peak Height : 4.41 (W/g)
Baseline Type : Tangential Sigmoid
4
HeatFlow (W/g)
3
2
1
0
-1
-2
-3
128.16 (°C)
-4
125
.
150
175
200
225
250
Temperature (°C)
275
300
325
Typical DSC trace of
3-methyl-4-nitrophenol recorded at 4 K/min and
sigmoid baseline construction.
5
Reproducibility of the DSC traces
Reaction rate (-/s)
2E-3
1.5E-3
1E-3
5E-4
0
200
.
220
240
260
280
Temperature (°C)
300
320
340
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.
6
Differential isoconversional method
Theory:
isoconversional analysis
&
baseline optimization
2
2
1
3
3
=
E 1
 d 
ln 
  Const 
R T
 dt  ln
7
Reactions rate and progress: Non-isothermal
Reaction rate (-/s)
Reaction rates d/dt and progresses  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.
0.003
4
8
0.002
4
.
1
0.001
2
0.5
0.25
0
1
Reaction progress (-)
0.25
0.5
0.8
1
2
0.6
4
8
0.4
4
4
0.2
.
0
200
.
220
240
260
280
Temperature (°C)
300
320
340
8
Reactions rate and progress: Isothermal
Reaction rates d/dt and progresses  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.
260
6E-4
220
Reaction rate (-/s)
5E-4
250
4E-4
240
3E-4
2E-4
.
230
220
1E-4
210
200
190
0
Reaction progress (-)
1
260
250
0.8
240
230
0.6
220
220
210
0.4
200
0.2
.
190
0
0
.
2
4
6
8
Time (h)
10
12
14
16
9
Experimental Validation
Isothermal validation
 ARC validation
 Initial temperature for TMRad 24h = ? °C
10
Link between kinetics and TMRad
Determination of time to maximum rate
under adiabatic conditions (TMRad)
Adiabatic Conditions
Or
=
From DSC
> 1000 kg
Theory
11
Key parameters in adiabatic experiments
Theory
Temperature /°C
Temperature profile of an adiabatic
runaway reaction,
DTadiabatic
Determination of
time to maximum rate under adiabatic conditions (TMRad)
Key parameters obtained from adiabatic experiments
Time /h
12
Key parameters in adiabatic experiments
Theory
Temperature /°C
Time to Maximum Rateadiabatic
Maximum
Selfheat rate
Selfheat rate /°C/min
Temperature profile of an adiabatic
runaway reaction,
corresponding self-heating rate
DTadiabatic
Determination of
time to maximum rate under adiabatic conditions (TMRad)
Key parameters obtained from adiabatic experiments
Time /h
13
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.
500
450
t: 15.67 (h)
T: 421.65 (°C(
400
300
250
200
150
t: 11.29 (h)
T: 183.81 (°C)
100
50
1
0.8
0.6
0.4
0.2
0
Reaction Progress: 0.0095 (-)
0
2
4
6
8
Time (h)
10
12
14
Reaction Progress (-)
Temperature (°C)
350
16
14
Experimental Validation
Isothermal validation
ARC validation
 Initial temperature for TMRad 24h = ? °C (F =1)
15
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.
Participant of
round
robin test
Heating rates
applied
(non-isothermal)
Temperatures applied
(isothermal)
0.25, 0.5, 1, 2, 4
200, 210, 220, 240
0.5, 1, 2, 4, 8
DHr ± s
Initial
temperature
for TMRad =
24 h
Sum of all
correl.
coeff.
1961.2± 151.8
156.4
9960
2070.5 ± 166.7
153.6
9894
4, 4
220, 240, 260
2143.2 ± 115.1
148.9
9932
0.5, 2, 4, 8
210, 220, 230, 240
2133.8 ± 144.7
149.4
9934
148
2.5, 2.5
190, 200, 210, 220
5
220, 230, 240, 250, 260
2112.1 ± 76.5
152.5
9978
1655.8 ± 141.9
150.1
9972
Mean value for TMRad 24h = 151.27 ±3.01°C
16
Experimental Validation
Isothermal validation
ARC validation
Initial temperature for TMRad 24h = 151°C (F =1)
17
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.
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Advanced Kinetics and Technology Solutions
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
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