Smart Technology for Evaluating Fire Extinguishing Effect of tert-Butyl

Jul 16, 2013 - The results could be available to fire-related agencies as a reference application. The fire extinguishing system must be well-designed...
0 downloads 0 Views 2MB Size
Download PDF
Article pubs.acs.org/IECR

Smart Technology for Evaluating Fire Extinguishing Effect of tert-Butyl Hydroperoxide Kuo-Yi Li Department of Industrial Engineering and Management, National Chin-Yi University of Technology, 57, Sec. 2, Zhongshan Rd., Taiping District, Taichung, Taiwan 41170, Republic of China

Shu-Yao Tsai Department of Health and Nutrition Biotechnology, College of Health Science, Asia University, 500, Lioufeng Rd., Wufeng, Taichung, Taiwan 41354, Republic of China

Chun-Ping Lin* Department of Health and Nutrition Biotechnology, College of Health Science, Asia University, 500, Lioufeng Rd., Wufeng, Taichung, Taiwan 41354, Republic of China, and Department of Occupational Safety and Health, China Medical University, 91, Hsueh-Shih Road, Taichung, Taiwan 40402, Republic of China

Yun-Ting Tsai and Chi-Min Shu Department of Safety, Health, and Environmental Engineering, National Yunlin University of Science and Technology, 123 University Rd., Sec. 3, Douliou, Yunlin, Taiwan 64002, Republic of China S Supporting Information *

ABSTRACT: tert-Butyl hydroperoxide (TBHP, 70 mass %), which is a solution of liquid peroxide, has been widely employed in the chemical industry as a polymerization initiator. The smart technology for predicting the mechanism of thermal decomposition and the inhibitive or hazardous reaction of TBHP by different calorimetric tests involves using differential scanning calorimetry (DSC) nonisothermal tests versus DSC isothermal tests and vent sizing package 2 (VSP2) adiabatic tests versus DSC nonisothermal tests, respectively, for further understanding how to extinguish organic peroxide accidents under fire scenario or runaway reaction in a chemical plant. Meanwhile, TBHP mixed with inhibitive and hazardous materials, such as various protic acids to help prevent runaway reactions, was applied on fires or explosions in the fire system. The results could be available to fire-related agencies as a reference application. The fire extinguishing system must be well-designed to decrease the degree of hazard.

1. INTRODUCTION tert-Butyl hydroperoxide (TBHP) is a solution of liquid organic peroxide that has been widely employed in the chemical industry and used to manufacture polymer materials. It is a commercial liquid organic peroxide that must be stored under limited temperature. In terms of manufacturing and storage management, many serious explosions and high ambient temperature have occurred from its thermal decomposition and incompatible reaction.1−4 Organic peroxides have caused many serious accidents including fire extinguishing accidents, tank storage, and transportation. One reason for accidents involves the peroxy group (−O−O−) of organic peroxides, because of its thermal instability and high sensitivity to thermal sources or ambient temperature.5−15 Table 1 shows the selected thermal explosion accidents caused by organic peroxides in Asia,10,13 and the thermal runaway reaction and explosion accidents of organic peroxides in chemical plant in Taiwan are displayed in Figure 1. © 2013 American Chemical Society

In particular, organic peroxides cannot be mixed with incompatible materials, such as strong acid strong base and special metal powder, which are used for extinguishing fires involving organic peroxides in the chemical plant. Actually, suitable firefighting equipment can be applied to reduce losses and protect life and property. Monoammonium phosphate, which is a fireextinguishing agent, has been used in the current fire extinguishing system.16,17 This study focused on organic peroxide mixed with phosphoric acid or other protic acids, such as sulfuric acid and nitric acid, which can be used for understanding inhibitive and hazardous reactions of organic peroxides under thermal decompositions, and which also could be used to optimize the fire extinguishing system to decrease the degree of hazard of organic peroxide accidents. Received: Revised: Accepted: Published: 10969

February 7, 2013 July 12, 2013 July 16, 2013 July 16, 2013 dx.doi.org/10.1021/ie400442f | Ind. Eng. Chem. Res. 2013, 52, 10969−10976

Industrial & Engineering Chemistry Research

Article

peroxides can be evaluated. Comparisons of swift nonisothermal and isothermal-kinetic model simulations led to a reliable mechanism of thermal decomposition to predict the parameters of TBHP.11,12 The selected approach was to establish an effective model for thermal decomposition that included the following kinetic parameters and thermal hazard properties:8−12 activation energy (Ea), frequency factor (ln k0), heat of decomposition (ΔHd), and reaction order (n) of TBHP, etc. Second, we considered the scenarios when various protic acids (e.g., monoprotic acid (HNO3), diprotic acid (H2SO4), and triprotic acid (H3PO4)) are mixed to predict the inhibitive and hazardous materials in the thermal stability of TBHP. The reaction equations of protic acids from eqs 1−3 are as follows:18

Table 1. Selected Thermal Explosion Accidents Caused by Organic Peroxides in Asiaa yearb

location

hazardc

number of injuries

number of fatalities

unitsd

1953 1953 1958 1958 1958 1960 1962 1964 1964 1965 1978 1979 1981 1982 1986 1987 1988 1989 1989 1989 1996 2000 2008 2009 2010

Tokyo Hyougo Tokyo Aichi Nara Tokyo Tokyo Tokyo Tokyo Tokyo Kanagawa Taiwan Taiwan Taiwan Taiwan Taiwan Taiwan Taiwan Taiwan Taiwan Taiwan Korea Taiwan Taiwan Taiwan

explosion explosion explosion explosion explosion explosion explosion explosion explosion explosion explosion explosion explosion explosion explosion explosion explosion fire explosion explosion explosion explosion explosion explosion explosion

3 1 0 1 0 0 0 19 0 0 0 49 3 55 0 20 19 0 0 5 47 11 0 0 0

0 0 0 0 0 0 0 114 0 0 0 33 1 5 0 0 0 0 0 7 10 3 0 0 0

N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A storage distillator reactor reactor tank tank tank tank tank tank storage reactor reactor reactor

Monoprotic acid: HNO3 + H 2O ⇌ H3O+ + NO3−

(1)

Diprotic acid: H 2SO4 + H 2O ⇌ H3O+ + HSO4 − HSO4 − + H 2O ⇌ H3O+ + SO4 2 −

(2)

Triprotic acid: H3PO4 + H 2O ⇌ H3O+ + H 2PO4 − H 2PO4 − + H 2O ⇌ H3O+ + HPO4 2 − HPO4 2 − + H 2O ⇌ H3O+ + PO4 3 −

a

Data taken from refs 10 and 13. bYear in which the accident occurred. Main reason why the accident occurred. dAccident occurred in the starting equipment. N/A = not available. c

(3)

Following the above-mentioned reactions for the prediction results of the original sample of TBHP, we then compared the DSC nonisothermal and the vent sizing package 2 (VSP2) adiabatic-kinetic model simulations to predict the runaway reaction, the inhibitive reaction, and the hazardous reaction of TBHP mixed with various protic acids. Kinetic model simulation was employed to construct a novel and effective procedure to evaluate the safety parameters for the inhibitive and hazardous reaction of TBHP. The chosen approach could establish a smart technology for thermal decomposition properties that includes the kinetics and hazardous reaction for TBHP, and when mixed with inhibitive or hazardous materials, respectively. The approach applies the optimal conditions to avoid TBHP’s violent runaway reactions during process manufacturing and storage. Ultimately, this study’s results could be available to firerelated agencies as a reference application. However, in earlier

TBHP is also very sensitive to heat due to the unstable structure of the peroxy group. If temperature is not wellcontrolled, the system becomes unstable and eventually triggers a runaway reaction in the next stage, potentially leading to various types of accidents.1,2 Organic peroxides have complex decomposition characteristics, and we still lack detailed information about them, especially during the runaway reactions. This focus of this study on TBHP is on inhibitive and hazardous reactions of mixing with various protic acids, evaluation of the thermal hazards, and discussion of the phenomenon of runaway reactions. First, we could achieve our objective by using a special method involving novel and effective thermal analysis technology. Via simple differential scanning calorimetry (DSC) tests and kinetics predictions, the thermal hazard properties of organic

Figure 1. (a) A thermal explosion and runaway reaction of organic peroxide at Taoyuan County that killed 10 people (including 6 fire fighters) and injured 47 in Taiwan (October 7, 1996). (b) Thermal runaway reaction and explosion accidents of organic peroxides in Taiwan (January 8, 2010). 10970

dx.doi.org/10.1021/ie400442f | Ind. Eng. Chem. Res. 2013, 52, 10969−10976

Industrial & Engineering Chemistry Research

Article

where k1 and k2 are rate constants of a specific reaction or stage, and n3 is the reaction order of Stage 3.

studies, the thermal hazard analysis method was rarely employed to assess and calculate the inhibitive and hazardous reaction for TBHP mixed with various protic acids. The fire extinguishing system must be well-designed to decrease the degree of hazard. Disaster can be prevented in the first stage, and the results of this study are expected to aid process safety for preventing an accident from occurring.

3. EXPERIMENTAL PROCEDURE AND METHODOLOGY 3.1. Samples. TBHP (70 mass % solution), which was supplied directly from ACE Chemical Corp in Taiwan, was stored in a refrigerator at 4 °C. Experiments involving DSC nonisothermal tests were conducted at various scanning rates of 1 and 2 °C/min. DSC isothermal tests were held at 125 and 130 °C for TBHP. The original TBHP 15 mass % (20 mL), the TBHP 15 mass % mixed with 4 mL of 6N HNO3, the TBHP 15 mass % mixed in 4 mL of 6N H2SO4, and the TBHP 15 mass % mixed in 4 mL of 6N H3PO4 were analyzed, respectively, by VSP2 adiabatic runaway reaction tests. Generally, to avoid bursting the test cell and losing all of the exothermic data, the tests were only performed on samples with 10−25 mass %. Thus, the concentration of TBHP was also 15 mass % for each VSP2 test in this study. 3.2. Differential Scanning Calorimetry (DSC). Temperatureprogrammed screening experiments were performed using DSC (TA Q20). The test cell was used to carry out the experiment for withstanding relatively high pressure (up to ∼10 MPa). ASTM Standard E698 was used to obtain thermal curves to calculate the kinetic parameters. Approximately 2−3 mg of the sample was used to acquire the experimental data of nonisothermal tests and isothermal tests. We used nitrogen as the carrier gas, the flow rate of which was 15 mL/min. Programmed temperature ramps of 1, 2, 4, and 8 °C/min were selected for nonisothermal tests of the scanning rate. The range of temperature rise chosen was 30−300 °C for each experiment. Several isothermal tests were performed under isothermal conditions at 125, 130, 135, and 140 °C. The results for the thermal decompositions of TBHP from the nonisothermal and isothermal of DSC tests are listed in Table 2, and the test curves of DSC are shown in Figure 2.

2. KINETIC SIMULATION Simulations of kinetic models can be complex multistage reactions that may consist of several independent, parallel, and consecutive stages, demonstrated as described by the following equations.8−12 The initial conditions are as follows: dα1 = r1 = k1(T )f1 (4) dt da 2 = r1 − r2 ; dt

r2 = k 2(T )f2

(5)

dα3 = r2 − r3; dt

r3 = k 3(T )f3

(6)

dα4 = r3 dt

t = 0;

(7)

αi = 0;

(i = 1, 2, 3, 4)

where α1, α2, α3, and α4 are the degrees of conversion of a reaction or stage, r1, r2, and r3 are reaction rates of a reaction or stage, k1, k2, and k3 are the rate constants of a reaction or stage, and f1, f 2, and f 3 are the kinetic functions of a reaction or stage. Simple one‐step reaction: A→B: dα = k 0 e−Ea /(RT )f (α) dt

(8)

f (α) = (1 − α)n n th‐order

(9)

f (α) = (1 − α)n1 (α n2 + z) autocatalytic

Table 2. Results of Various DSC Tests of TBHP with Scanning Rates of 1, 2, 4, and 8 °C/min and under Different Isothermal Conditions at Temperatures of 125, 130, 135, and 140 °C

(10)

where Ea is the activation energy, k0 is the pre-exponential factor, z is the autocatalytic constant, and n1 and n2 are reaction orders of the specific stage.

Isothermal Heating Conditionsa sample mass (mg) 2.8 2.6 3.3 2.9

Reaction including two consecutive stages: A→B→C:

dα = k1 e−E1/(RT )(1 − α)n1 ; dt dγ = k 2 e−E2 /(RT )(α − γ )n2 dt

(11)

where α and γ are the conversions of the reactant A and product C, respectively, and E1 and E2 are activation energies of Stage 1 and Stage 2, respectively.

scanning rate (°C/min)

peak temperature, Tp (°C)

1 134.9 2 142.5 4 149.1 8 158.8 Nonisothermal Conditionsb

ΔHdc (kJ/kg) 883.6 999.0 746.2 956.9

sample mass (mg)

temperature (°C)

maximum heat flow (mW)

ΔHdc (kJ/kg)

2.5 2.3 2.7 2.3

125 130 135 140

2.82 2.79 5.62 3.88

776.9 708.3 730.6 718.6

a

Isothermal heating conditions of the DSC test (scanning rate and peak temperature of DSC nonisothermal test). bNonisothermal heating conditions of the DSC test (temperature and maximum heat flow of DSC isothermal test). cHeat of decomposition by DSC test.

Two-parallel equations are a useful model of full autocatalysis: dα = r1(α) + r2(α); dt

r1(α) = k1(T )(1 − α)n1 r2(α) = k 2(T )α n2(1 − α)n3

In addition, nonisothermal hazardous reaction tests were conducted at a scanning rate of 4 °C/min; ∼6−7 mg of the

(12) 10971

dx.doi.org/10.1021/ie400442f | Ind. Eng. Chem. Res. 2013, 52, 10969−10976

Industrial & Engineering Chemistry Research

Article

conditions, the main heater will heat the sample to a preset temperature, and then a guard heater turns on to maintain an adiabatic surrounding.19 In the experimental conditions, if the self-heating rate is larger than 0.02 °C/min the heat-wait-search stage and main heater should be immediately stopped, to measure the original phenomenon of self-exothermicity.20 To adequately protect the normal operation of this apparatus and avoid bursting the test cell and losing the end of exothermic data, TBHP 15 mass % (20 mL) samples, mixed with 4 mL of 6N HNO3, 4 mL of 6N H2SO4, or 4 mL of 6N H3PO4, were prudently prepared for the experiments. Thermokinetic and pressure behavior in the same test cell (112 mL) usually could be tested without any difficult extrapolation to the process scale, because of a low thermal inertia factor (Φ) of ∼1.05− 1.32. Here, a value of Φ = 1.1 was applied to evaluate the runaway reaction and simulate the kinetic parameters in this study. The VSP2 test results for the adiabatic runaway reaction of the TBHP 15 mass %, mixed with 6N HNO3, 6N H2SO4, or 6N H3PO4 are shown in Table 4. The temperature versus time and the pressure versus time are presented in Figures 4 and 5.

Figure 2. DSC curves of heat flow versus temperature for TBHP decomposition with scanning rates of 1, 2, 4, and 8 °C/min and isothermal temperatures of 125, 130, 135, and 140 °C.

sample were used to acquire the experimental data, and the range of temperature rise chosen was 30−300 °C for each experiment. The results for the thermal decompositions of TBHP from the DSC nonisothermal hazardous reaction tests are given in Table 3, and the test curves of DSC are shown in Figure 3.

Table 4. Results of Thermal Runaway Reaction of TBHP and Mixed with Various Protic Acids by VSP2 Tests

Table 3. Results of Hazardous Reaction of TBHP Mixed with Various Protic Acids by DSC Nonisothermal Tests

a

sample mass (mg)

mixed material

heat of decomposition, ΔHda (kJ/kg)

6.2 6.7 7.1

TBHP + 6N HNO3 TBHP + 6N H2SO4 TBHP + 6N H3PO4

2073.4 1113.4 1126.2

samplea

Tmaxb

Pmaxc

(dP/dt)maxd

(dT/dt)maxe

TBHP TBHP + 6N HNO3 TBHP + 6N H2SO4 TBHP + 6N H3PO4

243.9 219.3 286.5 163.7

33.3 42.6 23.0 11.4

1.9 2469.5 1642.9 0.3

84.9 3448.3 5186.6 42.9

a

Samples include original TBHP and TBHP 15 mass % (20 mL) samples, with 4 mL of various 6N protic acids, respectively. b Maximum explosion pressure (°C) by VSP2 test. cMaximum explosion pressure (bar) by VSP2 test. dMaximum rate of explosion pressure rise (bar/min) by VSP2 test. eMaximum rate of explosion temperature rise (°C/min) by VSP2 test.

Heat of decomposition by DSC test.

Figure 4. Temperature versus time for thermal runaway reaction of TBHP with various protic acids by VSP2. Figure 3. DSC nonisothermal curves of heat flow versus temperature for TBHP mixed with the decomposition of various protic acids (HNO3, H2SO4, H3PO4) with a scanning rate of 4 °C/min.

4. RESULTS AND DISCUSSION 4.1. Evaluation of TBHP Mechanism of Thermal Decomposition by DSC. The kinetic parameters were determined from the DSC experimental data at various scanning rates of 1, 2, 4, and 8 °C/min and isothermal tests conducted under isothermal conditions at temperatures of 125, 130, 135, and 140 °C for TBHP. The thermal decomposition of TBHP represents an unknown reaction mechanism, such as an

3.3. Vent Sizing Package 2 (VSP2). VSP2, developed by Fauske and Associates, Inc., is a highly sensitive calorimeter that can obtain thermokinetic and thermal decomposition data, such as temperature and pressure traces, with respect to time in an adiabatic calorimeter system by PC-control. Under heating 10972

dx.doi.org/10.1021/ie400442f | Ind. Eng. Chem. Res. 2013, 52, 10969−10976

Industrial & Engineering Chemistry Research

Article

overheating effect of the kinetic parameters for TBHP. Fortunately, the comparisons of the kinetics of nonisothermal and isothermal kinetic-model simulation, and the kinetic parameters of TBHP, indicate that the mechanism of thermal decomposition belongs to an autocatalytic reaction in this study. 4.2. Prediction of TBHP Inhibitive and Hazardous Reaction by DSC and VSP2. Table 3 shows the results of the inhibitive and hazardous reactions of TBHP mixed with various protic acids by DSC nonisothermal tests. In contrast to Tables 2 and 3, for the TBPB mixed with 6N HNO3, the heat of decomposition was greater than those observed for the other polyprotic acids, which was also more than the original samples of TBHP (see Table 2). Thus, from the result of inhibitive and hazardous reaction of nonisothermal tests, we could observe the mixing with 6N HNO3 in TBHP, which causes a hazardous reaction for TBHP. Figure 4 shows the temperature versus time for thermal decomposition of the TBHP 15 mass %, mixed with 6N HNO3, 6N H2SO4, and 6N H3PO4 by VSP2. The pressure versus time by VSP2 under TBHP 15 mass % mixed with various protic acids is shown in Figure 5. When TBHP was mixed with 6N H2SO4, as in Figure 4, Tmax reached 286.5 °C; in Figure 5, when TBHP was mixed with 6N HNO3, Pmax reached 42.6 bar, which was greater than that of the other polyprotic acids. Respectively, the (dT/dt)max and (dP/dt)max values of TBHP mixed with 6N HNO 3 were ∼3448.3 °C/min and ∼2469.5 bar/min, respectively (see Table 4). The critical point for the chemical explosion under constant volume reactor immediately reaches the maximum pressure, which is a very dangerous condition for process manufacturing or storage. Accordingly, the kinetics of the thermal decomposition of TBHP was predicted from autocatalytic reaction simulation. Tables 6 and 7 present the results of the nonisothermal and adiabatic kinetic-model autocatalytic simulations, respectively. From Table 6, in contrast to the fact that the use of simulated

Figure 5. Pressure versus time for thermal runaway reaction of TBHP with various protic acids by VSP2.

nth order or autocatalytic reaction. Comparisons of the TBHP’s DSC nonisothermal and isothermal tests of the experimental data and data derived from simulated nth order reaction and autocatalytic reaction, respectively (from Table 5) show that the results match very well those of the autocatalytic simulations for TBHP by simple nonisothermal and isothermal kinetic-model simulation, respectively. This is in contrast to the fact that the TBHP use of simulated autocatalytic kinetic models to match original DSC experimental data, respectively, was proven to give superior results. Moreover, a comparison of Tables 2 and 5 shows that the samples were tested under isothermal conditions; in comparison, the overheating effect was greater than that observed in the nonisothermal DSC tests. The result was explicit: the DSC isothermal tests simulation was not appropriately applied on TBHP’s kinetic evaluation in this study. The outcomes of DSC isothermal-kinetic-model simulation were concerned with the

Table 5. Comparisons of the Kinetic Parameters of TBHP for the Evaluation of nth-Order and Autocatalytic Models under Nonisothermal and Isothermal Conditionsa 1 °C/min nth-order ln(k0)b Eac (kJ/mol) nd n1e n2e zf ΔHdg (kJ/kg)

2 °C/min

nth-order

autocatalytic

21.09 94.09

25.42 108.59

22.73 97.51

26.64 112.15

20.76 90.17

25.31 107.86

21.36 92.26

0.72

0.90

0.72

1.12

0.72

0.96

0.75

1.06

N/A N/A 898.69

0.60 0.40 890.13

N/A N/A 1022.05

0.86 0.26 1006.95

N/A N/A 761.22

0.52 0.11 750.78

N/A N/A 983.52

0.67 0.22 971.89

autocatalytic

nth-order

autocatalytic

nth-order

autocatalytic

nth-order

125 °C nth-order b

ln(k0) Eac (kJ/mol) nd n1e n2e zf ΔHdg (kJ/kg)

autocatalytic

nth-order

8 °C/min

25.09 107.88

autocatalytic

nth-order

4 °C/min

130 °C

autocatalytic

135 °C

140 °C autocatalytic

28.18 114.62

22.13 90.67

37.83 148.78

22.00 91.25

31.39 126.63

22.68 91.86

23.48 105.06

22.43 89.93

0.71

1.83

0.83

2.99

0.69

2.48

0.2442

2.99

N/A N/A 706.68

0.55 1.376 × 10−3 708.29

N/A N/A 583.40

0.46 3.247 × 10−4 684.53

N/A N/A 787.62

0.70 1.591 × 10−4 820.48

N/A N/A 371.65

0.63 1.001 × 10−8 631.69

Heating condition: nonisothermal (°C/min) DSC test and isothermal (°C) DSC test, respectively. bPre-exponential factor [ln (s−1)] of thermal decomposition. cActivation energy of thermal decomposition. dnth order of thermal decomposition reaction. eReaction order of n1th and n2th stage for autocatalytic reaction of thermal decomposition. fAutocatalytic constant for autocatalytic reaction of thermal decomposition. gHeat of decomposition by simulation. a

10973

dx.doi.org/10.1021/ie400442f | Ind. Eng. Chem. Res. 2013, 52, 10969−10976

Industrial & Engineering Chemistry Research

Article

Table 6. Kinetic Parameters Evaluated for TBHP Mixed with Various Protic Acids by Nonisothermal Autocatalytic Model Simulationa b

ln(k0) Eac (kJ/mol) nd n1e n2e zf ΔHdg (kJ/kg)

HNO4

H2SO4

H3PO4

19.21

21.47

30.57

81.95

92.55

123.54

2.46 0.40 0.01 1644.67

1.86 0.22 0.02 1116.97

2.35 0.88 0.02 1020.43

a

Sample: TBHP mixed with various protic acid (6N) by nonisothermal autocatalytic model simulation. bPre-exponential factor [ln (s−1)] of thermal decomposition. cActivation energy of thermal decomposition. dnth order of thermal decomposition reaction. e Reaction order of n1th and n2th stage for autocatalytic reaction of thermal decomposition. fAutocatalytic constant only for autocatalytic reaction of thermal decomposition. gHeat of decomposition by simulation.

Figure 6. Inhibitive and hazardous reaction assessment of TBHP mixed with various protic acids time until the maximum rate and total energy release by DSC nonisothermal.

Table 7. Kinetic Parameters Evaluated for TBHP and Mixed with Various Protic Acids by Adiabatic Autocatalytic Model Simulationa TBHP ln(k0)b Eac (kJ/mol) nd n1e n2e zf ΔHdg (kJ/kg)

HNO3

H2SO4

H3PO4

41.91

33.72

43.54

7.80

108.50

75.07

121.50

204.00

0.52 0.31 0.02 169.92

1.68 0.85 9.055 × 10−3 89.91

0.56 0.33 0.77 176.55

1.00 0.06 3.000 × 10−3 100.00

a

Sample: TBHP (15 mass %, 20 mL), and TBHP mixed with various protic acids (6N, 4 mL) for adiabatic autocatalytic model simulation. b Pre-exponential factor [ln (s−1)] of thermal decomposition. c Activation energy of thermal decomposition. dnth order of thermal decomposition reaction. eReaction order of n1th and n2th stage for autocatalytic reaction of thermal decomposition. fAutocatalytic constant only for autocatalytic reaction of thermal decomposition. g Heat of decomposition by simulation.

Figure 7. Inhibitive and hazardous reaction assessment of TBHP mixed with various protic acids time until 10% conversion with DSC nonisothermal tests.

Figure 6 shows the TMRiso of TBHP and mixed in 6N H3PO4 were obtained, the values of which were