A method and system for judging reaction model based on DSC dynamic experiment

Abstract

The present invention discloses a method and system for judging a reaction model based on a DSC dynamic experiment, which is applicable to a single-step reaction, comprising: obtaining DSC dynamic experimental results of an experimental sample at different temperature rise rates; calculating RT at different temperature rise rates based on the DSC dynamic experimental results; p 2 q max / [βQ(1‑α p )] value, if the value is constant, it is considered that the decomposition reaction of the experimental sample is an n-order reaction, otherwise it is an autocatalytic decomposition reaction. The present invention verifies the effectiveness of the proposed criterion through numerical simulation calculations and experimental tests of four typical substances. The present invention does not require complex curve fitting and rich judgment experience, and can identify the reaction model by simply calculating the parameters in the original curves of different temperature rise rates.

Description

Technical Field

[0001] The present invention relates to the technical field of decomposition reaction model identification, and in particular to a method and system for judging a reaction model based on a differential scanning calorimeter (DSC) dynamic experiment. Background Art

[0002] The decomposition reactions of many hazardous substances follow an autocatalytic reaction mechanism. Compared with the n-order reaction model, autocatalytic reactions have a longer induction period, and the decomposition products can accelerate the reaction rate. This may lead to unpredictable sudden heat release, which is usually accompanied by significant destructive power, so this type of reaction is very dangerous. Therefore, the identification of autocatalytic decomposition is extremely important.

[0003] In 2002, the Swiss Institute of Security Technology and Assurance proposed a method for judging the reaction model based on the apparent activation energy of substances by statistically analyzing more than 100 substances. This method shows that if the apparent activation energy determined by the dynamic DSC test is higher than 220 kJ / mol, it is considered to be an autocatalytic reaction; for the apparent activation energy between 50 and 180 kJ / mol, the decomposition reaction is non-autocatalytic; when the apparent activation energy is between 180 and 220 kJ / mol and the deviation is less than 10%, other methods are required for judgment. In 2012, Sanchirico proposed a semi-empirical model using the topological structure of two dynamic DSC curves at different temperature rise rates. If the two curves intersect at a non-origin, the material can be described as an autocatalytic reaction. This method can be regarded as a method to assist in judging the autocatalytic model. The Malek method and the improved Malek method also use DSC dynamic experimental data to quantitatively describe the kinetic model of the reaction by comparing the experimental data and the theoretical calculation data, thereby judging the reaction model. To date, the isothermal method is the most widely used autocatalytic identification method at home and abroad. In the isothermal DSC test, the heat flow curve of catalytic decomposition presents a bell-shaped heat release rate curve, and the result is highly accurate. However, the selection of the isothermal DSC experimental temperature is crucial. If the set temperature is too low, there will be no decomposition within the test time. On the contrary, at too high a temperature, the induction time is so short that only part of the curve where the heat flow drops is detected, making the judgment result inaccurate. Therefore, it is necessary to select the isothermal temperature through a dynamic DSC test before the isothermal experiment. However, there is no exact standard for the selection of isothermal temperature for different substances, and experienced operators are required to screen. In addition, when there is an endothermic process before the exothermic reaction, a bell-shaped peak will also appear in the isothermal test, resulting in pseudo-autocatalysis. Roduit et al. found that a small amount of decomposition products has different effects on autocatalytic reactions and n-order reactions. If a small amount of decomposition products of a substance advances the starting decomposition temperature and peak temperature of the reaction, it is autocatalytic decomposition. This method requires two dynamic DSC experiments with the same temperature rise rate, one is a traditional dynamic experiment, and the other is interrupted when the reaction reaches the Ton temperature, cooled down and restarted from the starting point, and the starting decomposition temperature and peak temperature of the two experiments are compared to determine the reaction model. However, the existing mature methods for judging reaction models require operators with rich experience to conduct a large number of experiments or software calculations for judgment, such as complex fitting of reaction models, selection of isothermal temperature, etc. This requires relevant personnel to undergo professional knowledge and software operation training and assessment, as well as rich practical experience. Summary of the invention

[0004] Purpose of the invention: In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a method and system for judging the reaction model based on DSC dynamic experiment, which does not require complicated curve fitting and rich judgment experience. The reaction model can be identified by simply calculating the parameters in the original curve of different temperature rise rates.

[0005] Technical solution: To achieve the above-mentioned invention object, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for determining a reaction model based on a DSC dynamic experiment, which is applicable to a single-step reaction and comprises the following steps:

[0007] Obtain DSC dynamic test results of the experimental samples at different temperature rise rates;

[0008] Based on the DSC dynamic test results, calculate the RT at different temperature rise rates p 2 q max / [βQ(1-α p )] value, if RT p 2 q max / [βQ(1-α p )] value is constant, the decomposition reaction of the experimental sample is considered to be an n-order reaction, otherwise it is an autocatalytic decomposition reaction; where R is the ideal gas constant, T p is the peak temperature, q max is the maximum heat flow value, β is the temperature rise rate, Q is the total heat release of the reaction, α p It's the conversion rate.

[0009] As a preference, RT at different temperature rise rates p 2 q max / [βQ(1-α p )] The deviation of the value does not exceed 5%,

[0010] The value is considered constant and the deviation is the deviation between any two values.

[0011] As a preference, the parameter T p and q max Directly obtained from DSC experimental data, where q max is the ordinate of the peak value of the heat flow versus time curve or the heat flow versus temperature curve, T p It is the abscissa of the peak value of the heat flow versus temperature curve.

[0012] As a preferred embodiment, the conversion rate α p Q is the heat release corresponding to the peak temperature moment p The ratio of Q, parameter Q pand Q are obtained by integrating the curve of heat flow changing with time; let t p It is the peak moment, and its value is the abscissa of the peak value of the curve of heat flow changing with time; Q p and Q is the integral of heat flow over time on the heat flow versus time curve, Q p The integration range is t p Before time , the Q integral range is the entire curve.

[0013] Furthermore, according to RT p 2 q max / [βQ(1-α p )] = E / n, estimate the range of apparent activation energy E of the substance in the n-order reaction model.

[0014] In a second aspect, the present invention provides a system for determining a reaction model based on a DSC dynamic experiment, comprising:

[0015] A data acquisition unit, used to obtain DSC dynamic experimental results of the experimental samples at different temperature rise rates;

[0016] Calculation and judgment unit, used to calculate RT at different temperature rise rates based on DSC dynamic test results p 2 q max / [βQ(1-α p )] value, if RT p 2 q max / [βQ(1-α p )] value is constant, the decomposition reaction of the experimental sample is considered to be an n-order reaction, otherwise it is an autocatalytic decomposition reaction

[0017] Furthermore, the system further comprises: an estimation unit for calculating the value of the RT p 2 q max / [βQ(1-α p )] = E / n, estimate the range of apparent activation energy E of the substance in the n-order reaction model.

[0018] In a third aspect, the present invention provides a computer system comprising a memory, a processor, and a computer program / instruction stored in the memory and executable on the processor, wherein the computer program / instruction, when executed by the processor, implements the steps of a method for determining a reaction model based on a DSC dynamic experiment.

[0019] In a fourth aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for determining a reaction model based on a DSC dynamic experiment are implemented.

[0020] In a fifth aspect, the present invention provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the method for determining a reaction model based on a DSC dynamic experiment.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following advantages: The present invention establishes a simple criterion for the single-step reaction model, and calculates the RT under different temperature rise rates based on the DSC dynamic experimental results. p 2 q max / [βQ(1-α p )] value, if RT p 2 q max / [βQ(1-α p )] value is constant, it is considered to be an n-order reaction, otherwise it is an autocatalytic decomposition reaction. The present invention mathematically simulates n-order and autocatalytic decomposition at different temperature rise rates, and applies the method to 4 representative substances: DCP, TBPB, CHP and DMSO. The results show that the numerical simulation and experimental results verify the effectiveness of the criterion proposed by the present invention. The advantages of the present invention are that the dynamic experiment is convenient and the calculation is simple, and no complex curve fitting and rich judgment experience are required. The reaction model can be identified by simply calculating the parameters in the original curves of different temperature rise rates. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The figure is a flow chart of a method according to an embodiment of the present invention.

[0023] Figure 2 Schematic diagram of parameter calculation in an embodiment of the present invention.

[0024] Figure 3 This is the numerical simulation result diagram of the n-order reaction model.

[0025] Figure 4 This is the numerical simulation result of the autocatalytic reaction model.

[0026] Figure 5 RT for n-order reaction model and autocatalytic reaction model p 2 q max / [βQ(1-α p )] as the temperature rise rate changes.

[0027] Figure 6 This is the DSC dynamic experimental result diagram of DCP at different temperature rise rates.

[0028] Figure 7This is the model fitting result diagram of DCP under different temperature rise rates.

[0029] Figure 8 This is the DSC dynamic experimental result diagram of TBPB at different temperature rise rates.

[0030] Fig. 9 This is the model fitting result diagram of TBPB at different temperature rise rates.

[0031] Fig.10 This is the DSC dynamic experimental result diagram of CHP at different temperature rise rates.

[0032] Fig.11 This is the DSC dynamic experimental result diagram of DMSO at different temperature rise rates. DETAILED DESCRIPTION

[0033] The technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments.

[0034] First, the derivation process of the theoretical formula of the present invention is introduced.

[0035] Conversion rate α and temperature T are the main parameters that characterize the chemical reaction rate. The chemical reaction kinetic equation can be expressed as:

[0036]

[0037] Wherein, t is the reaction time, f(α) is the reaction mechanism model, and k(T) is the reaction rate constant. The reaction rate constant can be quantitatively expressed using the Arrhenius law, as shown in formula (2).

[0038] k(T)=k0e -E / RT (2)

[0039] where k0 is the pre-exponential factor; E is the apparent activation energy; and R is the ideal gas constant, 8.314 J.mol -1. K -1 In the case of programmed temperature control, the temperature rise rate can be expressed as formula (3).

[0040]

[0041] Substituting equation (2) and equation (3) into equation (1), we get:

[0042]

[0043] Formula (4) is a commonly used thermal analysis kinetic equation for chemical reactions under programmed temperature control conditions and is applicable to apparent single-step reactions.

[0044] For a single-step n-order reaction, f(α) can be expressed as formula (5).

[0045] f(α)=(1-α) n (5)

[0046] Substituting into equation (4), the reaction kinetic equation is:

[0047]

[0048] By taking the derivative of equation (6) with respect to temperature, we can obtain:

[0049]

[0050] Obviously, when d 2 α / dT 2 is equal to zero, dα / dT reaches its maximum value (dα / dT) max The corresponding temperature at this time is the peak temperature T p ; The conversion rate is α p . Then we have:

[0051]

[0052] The maximum heat flow value q in the DSC experimental curve max It can be expressed in terms of maximum reaction rate.

[0053]

[0054] Where Q t is the heat release corresponding to the reaction time t, and Q is the total heat release of the reaction. Substituting equations (3) and (9) into equation (8), we can obtain equation (10).

[0055]

[0056] Since the apparent activation energy and reaction order in the n-level model are considered constant, E / n is a constant in the same substance or reaction system. Therefore, for the n-level model, RT p 2 q max / [βQ(1-α p )] is theoretically constant.

[0057] There are many types of autocatalytic models, and their reaction mechanism functions are more complicated than those of the n-level model. The simple autocatalytic model, the Proto model, the Benito-Perez model, and the Erofeev model are four common autocatalytic models.

[0058] Substituting into the reaction mechanism model respectively, the self-heating rates corresponding to the four autocatalytic models are obtained. The first-order derivative is calculated, i.e., d 2 T / dt 2Similarly, make d 2 T / dt 2 zero, the four autocatalytic models cannot obtain simple numerical solutions, and changing the temperature rise rate RT p 2 q max / [βQ(1-α p )] will change. p 2 q max / [βQ(1-α p )] is substituted into d as a fixed value 2 T / dt 2 In the formula, we cannot get d 2 T / dt 2 The reaction mechanism models and formula derivation processes of the four autocatalytic models are shown in Table 1.

[0059] Table 1 Reaction mechanism models and formula derivation of four autocatalytic models

[0060]

[0061] In Table 1, z represents the autocatalytic parameter, n1 and n2 represent the reaction order in the model, and E z represents the effective activation energy, Z0 represents the pre-exponent of the expression, and the detailed parameter form can be found in the literature [Kossoy, AA, VM Belokhvostov, and E.Y. Koludarova, Thermal decomposition of AIBN: Part D: Verification of simulation method for SADT determination based on AIBN benchmark. Thermochimica Acta, 2015. 621: p. 36-43].

[0062] Based on the above discussion, equation (10) can be used as a criterion for judging whether an adiabatic reaction obeys the n-order model. Specifically, if RT p 2 q max / [βQ(1-α p )] is constant, the reaction is an n-order reaction; otherwise, the reaction follows an autocatalytic reaction mechanism.

[0063]

[0064] Based on the above theoretical derivation, Figure 1As shown, a method for determining a reaction model based on a DSC dynamic experiment disclosed in an embodiment of the present invention (applicable to a single-step reaction) comprises the following steps:

[0065] Obtain DSC dynamic experimental results of the experimental samples at different (at least two) temperature rise rates;

[0066] Based on the DSC dynamic test results, calculate the RT at different temperature rise rates p 2 q max / [βQ(1-α p )] value, if RT p 2 q max / [βQ(1-α p )] value is constant, the decomposition reaction of the experimental sample is considered to be an nth-order reaction, otherwise it is an autocatalytic decomposition reaction.

[0067] When making specific judgments, RT at different temperature rise rates p 2 q max / [βQ(1-α p )] values ​​are considered constant if the deviation between any two values ​​does not exceed 5%.

[0068] The main parameter T in the above criterion is p and q max can be obtained directly from experimental data, α p And Q also only need to be calculated by integrating the curve twice, without the need for precise mechanism model and calculation of dynamic parameters.

[0069] Specifically, if Figure 2 As shown in the figure, the red box marks the peak of the DSC experimental curve. max It is the ordinate of the peak value of the heat flow versus time curve or the heat flow versus temperature curve, T p It is the abscissa of the peak value of the heat flow versus temperature curve. p Q is the heat release corresponding to the peak temperature moment p The ratio of Q, parameter Q p and Q are obtained by integrating the curve of heat flow changing with time; let t p It is the peak moment, and its value is the abscissa of the peak value of the curve of heat flow changing with time; Q p and Q is the integral of heat flow over time on the heat flow versus time curve, Q p The integration range is t p Before the time (the blue shaded area in the figure), the Q integral range is the entire curve. The software program can get the peak value by determining the maximum value of the experimental data, and the integral can be obtained by summing the discrete data points.

[0070] For the n-order reaction model, since the range of n is 0.3 to 1.7 and n is close to 1 for most reactions, we can further estimate the range of the apparent activation energy E of the substance in the n-order reaction model according to formula (10).

[0071] The effectiveness of the criterion proposed in the present invention is verified from numerical simulation and experimental results respectively.

[0072] 1. Numerical simulation verification

[0073] 1. Numerical simulation verification of n-level model

[0074] The mechanism model of a single-step n-order reaction is shown in equation (5), and the set parameters are k0, E, n, and Q. The kinetic parameter settings for simulating the n-order model are shown in Table 2, and the ratio of activation energy to reaction order E / n is approximately 133.60 kJ / mol.

[0075] Figure 3 It is the result of numerical simulation of the n-level model, which contains 8 DSC test fitting curves with different temperature rise rates, including the curve of heat flow changing with time and the curve of heat flow changing with temperature. The range of β is 1.0K / min to 8.0K / min, with a value interval of 1.0K / min; the temperature range is 25℃ to 300℃.

[0076] Table 3 lists the relevant data results of the numerical simulation of the n-level model, and gives the RT p 2 q max / [βQ(1-α p )] and calculated the RT p 2 q max / [βQ(1-α p )] and the deviation of E / n.

[0077] Table 2 Kinetic parameter settings for numerical calculation of n-level model

[0078]

[0079] Table 3 RT of the numerical simulation of the n-stage reaction model p 2 q max / [βQ(1-α p )] value and deviation calculation

[0080]

[0081] In the kinetic parameters in Table 2, the ratio of activation energy to reaction order E / n is about 133.60 kJ / mol. From Table 3, the RT p2 q max / [βQ(1-α p )] are very close to 133.6 kJ / mol. RT p 2 q max / [βQ(1-α p )] and the set parameter value E / n have a very small deviation De, the maximum deviation does not exceed 0.88%. According to the criterion formula (11), changing the temperature rise rate, RT p 2 q max / [βQ(1-α p The constant calculated value of )] indicates that the kinetic model is an n-order model, which is completely consistent with the model setting in Table 3. Therefore, the results of the numerical simulation prove the validity of the criterion formula (11).

[0082] 2. Numerical simulation verification of the autocatalytic model

[0083] The reaction mechanism functions of the autocatalytic model are relatively complex. The simple autocatalytic model, Proto model, Benito-Perez model and Erofeev model are four common autocatalytic models. Among them, the Benito-Perez model is one of the most widely used autocatalytic models and the most representative. Its specific form can be described by equations (12) and (13). The mechanism contains two parallel reactions: the first is the initiation reaction, which is an n-order reaction model; the second is the autocatalytic reaction, which is represented by the autocatalytic model.

[0084]

[0085] The Benito-Perez model was used for numerical calculation verification. The kinetic parameter settings for simulating the autocatalytic model are shown in Table 4 (n 11 、n 21 、n 22 are the three reaction orders in the model). The MATLAB program is also used for simulation, and simulations are performed at different temperature rise rates.

[0086] Figure 4 It is the result of numerical simulation of Benito-Perez autocatalytic model, which contains 8 DSC test fitting curves with different temperature rise rates, including the curve of heat flow changing with time and the curve of heat flow changing with temperature. The range of β is 1.0K / min to 8.0K / min, with a value interval of 1.0K / min; the temperature range is 80℃ to 300℃.

[0087] Table 5 lists the relevant data results of the numerical simulation of the Benito-Perez autocatalytic model, and gives the RT p 2 q max / [βQ(1-α p )] and calculated the RT p 2 q max / [βQ(1-α p )] and the deviation of E / n.

[0088] Table 4 Kinetic parameter settings for the numerical calculation of the autocatalytic model

[0089]

[0090]

[0091] From Table 5, the RT at different temperature rise rates p 2 q max / [βQ(1-α p )] varies greatly. In this model, as the temperature rise rate increases, RT p 2 q max / [βQ(1-α p )] is decreasing. p 2 q max / [βQ(1-α p )] is used as the standard, and RT p 2 q max / [βQ(1-α p )] and its calculated value have a large deviation De, with the largest deviation reaching 78.58%. According to the criterion formula (11), changing the temperature rise rate, RT p 2 q max / [βQ(1-α p )] changes significantly, which indicates that the kinetic model is an autocatalytic model, and this conclusion is completely consistent with the model settings in Table 4. Therefore, the results of the numerical simulation prove the validity of the criterion formula (11).

[0092] Table 5 RT of the numerical simulation of the autocatalytic reaction model p 2 q max / [βQ(1-α p )] value and deviation calculation

[0093]

[0094] 3. Comparison of numerical simulation results between n-level model and autocatalytic model

[0095] In order to explain the criterion (11) more clearly, for the n-level model and the autocatalytic model, RT p 2 q max / [βQ(1-α p )] values. Figure 5 The RT of all n-order reaction models and autocatalytic reaction models under adiabatic conditions is plotted p 2 q max / [βQ(1-α p )] is the simulated calculated value.

[0096] As can be seen from the figure, changing the temperature rise rate has an impact on the RT of the two groups of simulations of the n-level model. p 2 q max / [βQ(1-α p )] value, the calculated value can be considered to remain constant and approximately equal to E / n. However, for the autocatalytic model, changing the temperature rise rate has no effect on RT p 2 q max / [βQ(1-α p )] has a large fluctuation. Obviously, the above numerical simulation results effectively verify the criterion (11).

[0097] 2. Experimental Verification

[0098] 1. Samples and test conditions

[0099] TBPB (tert-butyl perbenzoate): purity 98.5%. DCP (diisopropylbenzene peroxide): purity 99%. CHP (isopropylbenzene hydroperoxide): purity 88%. DMSO (dimethyl sulfoxide): purity 88%. All manufacturers are Aladdin Reagent Company.

[0100] The DSC1 used was produced by Mettler Toledo, Germany. The sample cell was a high-pressure 316 stainless steel crucible. The sample mass was (1.99±0.01) mg. The temperature range was 30-200°C. The dynamic temperature rise rates were 1, 2, 4, and 8 K min, respectively. -1 .

[0101] 2. Experimental results of n-level model

[0102] The thermal decomposition reaction of DCP and TBPB is a typical n-order reaction model. To verify the criterion (11), these two substances were selected to conduct multiple DSC tests at different temperature rise rates. It should be noted that qmax The unit is J / (g.min), which is related to the sample mass.

[0103] First, a dynamic test was conducted on the DCP. Figure 6 Table 6 shows the DSC dynamic test results of DCP at different temperature rise rates. p 2 q max / [βQ(1-α p )] value. Although the T p , α p ,q max and Q have changed, but RT p 2 q max / [βQ(1-α p )] is almost constant. According to the criterion formula (11), DCP can be judged as an n-order reaction model.

[0104] Table 6 Parameter values ​​and RT of DCP at different temperature rise rates p 2 q max / [βQ(1-α p )] value calculation result

[0105]

[0106] To further demonstrate formula (11), the kinetic parameters of DCP were calculated by model fitting method, and the obtained kinetic parameters are shown in Table 7. Figure 7 The model fitting results of DCP at different temperature rise rates. The E obtained by the model fitting method is 165.14 kJ / mol, n is 0.98, and the value of E / n is 167.99 (kJ / mol). p 2 q max / [βQ(1-α p )], and the deviation results are shown in Table 8. RT at different temperature rise rates p 2 q max / [βQ(1-α p The deviation between the calculated value and the E / n value calculated by the model fitting method does not exceed 0.59%. This further confirms that for the n-level model RT p 2 q max / [βQ(1-α p )] The calculated value is the value of E / n, which illustrates the accuracy of the theoretical derivation and the effectiveness of the criterion formula (11).

[0107] Table 7 DCP kinetic parameters calculated by model fitting method

[0108]

[0109] Table 8 RT of DCP at different temperature rise rates p 2 q max / [βQ(1-α p )] value and the deviation result of E / n value

[0110]

[0111] The thermal decomposition of TBPB is also a typical n-level model. Dynamic tests are performed on it. Figure 8 Table 9 shows the DSC dynamic test results of TBPB at different temperature rise rates. Table 9 shows the parameter values ​​and RT of TBPB at different temperature rise rates. p 2 q max / [βQ(1-α p )] value calculation result.

[0112] Table 9 Parameter values ​​and RT of TBPB at different temperature rise rates p 2 q max / [βQ(1-α p )] value calculation result

[0113]

[0114] In Table 9, although T p , α p ,q max and Q have changed, but RT p 2 q max / [βQ(1-α p )] is almost constant. According to the criterion formula (11), TBPB can be judged as an n-order reaction model.

[0115] To further demonstrate formula (11), the kinetic parameters of TBPB were calculated by model fitting method, and the obtained kinetic parameters are shown in Table 10. Fig. 9 The model fitting results of TBPB at different temperature rise rates. The E obtained by the model fitting method is 122.76 kJ / mol, n is 1.21, and the value of E / n is 167.99 kJ / mol. p 2 q max / [βQ(1-α p )], and the deviation results are shown in Table 11. RT at different temperature rise ratesp 2 q max / [βQ(1-α p )] calculated value and the E / n value calculated by the model fitting method do not exceed 1.60%. This further confirms that for the n-level model RT p 2 q max / [βQ(1-α p )] The calculated value is the value of E / n, which illustrates the accuracy of the theoretical derivation and the effectiveness of the criterion formula (11).

[0116] Table 10 TBPB kinetic parameters calculated by model fitting method

[0117]

[0118] Table 11 RT of TBPB at different temperature rise rates p 2 q max / [βQ(1-α p )] value and the deviation result of E / n value

[0119]

[0120] 3. Experimental results of autocatalytic model

[0121] The decomposition of CHP and the first stage heat release of DMSO are autocatalytic reaction models. In order to verify the autocatalytic part in the criterion formula (11), these two substances were selected for multiple DSC experiments.

[0122] First, a dynamic test of CHP was conducted. Fig.10 Table 12 shows the DSC dynamic experimental results of CHP at different temperature rise rates. p 2 q max / [βQ(1-α p )] value calculation results. Among them, T p , α p ,q max and Q have changed, and RT p 2 q max / [βQ(1-α p)] varies greatly, ranging from 273.97 to 315.22 kJ / mol. According to criterion formula (11), CHP can be judged as an autocatalytic reaction model, which is consistent with the conclusion in the literature [Cao, C.-R., et al., Evaluation for the thermokinetics of the autocatalytic reaction of cumenehydroperoxide mixed with phenol through isothermal approaches and simulations. Process Safety and Environmental Protection, 2018.117: p.426-438]. The experimental results of this substance verify the validity of criterion formula (11).

[0123] Table 12 Parameter values ​​and RT of CHP at different temperature rise rates p 2 q max / [βQ(1-α p )] value calculation result

[0124]

[0125] The first stage of thermal decomposition of DMSO is also a typical autocatalytic reaction model. Dynamic tests were performed on it. Fig.11 Table 13 shows the parameter values ​​and RT of TBPB at different temperature rise rates. p 2 q max / [βQ(1-α p )] value calculation results. Among them, T p , α p ,q max and Q have changed, and RT p 2 q max / [βQ(1-α p)] The calculated values ​​vary greatly, ranging from 535.14 to 2889.23 kJ / mol. According to criterion formula (11), DMSO can be judged as an autocatalytic reaction model, which is consistent with the conclusion in the literature [Wu, W., et al., Effect of Zinc Oxide on the Thermal Decomposition of Dimethyl Sulfoxide. Organic Process Research & Development, 2022. 26 (4): p. 1038-1047.]. The experimental results of this substance once again verified the validity of criterion formula (11).

[0126] Table 13 Parameter values ​​and RT of DMSO at different temperature rise rates p 2 q max / [βQ(1-α p )] value calculation result

[0127]

[0128] The present invention establishes a simple criterion for the single-step reaction model. The criterion shows that the RT obtained by DSC experiment under different temperature rise rates p 2 q max / [βQ(1-α p )] is a constant, the decomposition is an n-order reaction; otherwise, it is an autocatalytic decomposition reaction. The advantages of this method are that it is convenient for dynamic experiments and simple for calculation. At the same time, there is no need to determine the isothermal temperature or calculate the kinetic parameters. Numerical simulation and experimental results verify the effectiveness of this criterion.

[0129] Based on the same inventive concept, a system for judging a reaction model based on a DSC dynamic experiment is disclosed in an embodiment of the present invention, comprising: a data acquisition unit for obtaining DSC dynamic experimental results of experimental samples at different temperature rise rates; a calculation and judgment unit for calculating RT at different temperature rise rates based on the DSC dynamic experimental results. p 2 q max / [βQ(1-α p )] value, if RT p 2 q max / [βQ(1-α p )] value is constant, the decomposition reaction of the experimental sample is considered to be an nth-order reaction, otherwise it is an autocatalytic decomposition reaction.

[0130] Furthermore, the system further comprises: an estimation unit for calculating the value of the RT p 2q max / [βQ(1-α p )] = E / n, estimate the range of apparent activation energy E of the substance in the n-order reaction model.

[0131] An embodiment of the present invention also discloses a computer system, including a memory, a processor, and a computer program / instruction stored in the memory and executable on the processor. When the computer program / instruction is executed by the processor, the steps of the method for determining a reaction model based on a DSC dynamic experiment are implemented.

[0132] The embodiment of the present invention further discloses a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for determining a reaction model based on a DSC dynamic experiment are implemented.

[0133] The embodiment of the present invention further discloses a computer program product, including a computer program / instruction, which implements the steps of the method for determining a reaction model based on a DSC dynamic experiment when executed by a processor.

Claims

1. A method for determining a reaction model based on a DSC dynamic experiment, suitable for a single-step reaction, characterized in that: The steps include: Obtain DSC dynamic test results of the experimental samples at different temperature rise rates; Based on the DSC dynamic test results, calculate the RT at different temperature rise rates p 2 q max / [βQ(1-α p )] value, if RT p 2 q max / [βQ(1-α p )] value is constant, the decomposition reaction of the experimental sample is considered to be an n-order reaction, otherwise it is an autocatalytic decomposition reaction; where R is the ideal gas constant, T p is the peak temperature, q max is the maximum heat flow value, β is the temperature rise rate, Q is the total heat release of the reaction, α p It's the conversion rate.

2. The method for determining a reaction model based on a DSC dynamic experiment according to claim 1, characterized in that: RT at different temperature rise rates p 2 q max / [βQ(1-α p )] values ​​are considered constant if the deviation between any two values ​​does not exceed 5%.

3. The method for determining a reaction model based on a DSC dynamic experiment according to claim 1, characterized in that: Parameter T p and q max Directly obtained from DSC experimental data, where q max is the ordinate of the peak value of the heat flow versus time curve or the heat flow versus temperature curve, T p It is the abscissa of the peak value of the heat flow versus temperature curve.

4. The method for determining a reaction model based on a DSC dynamic experiment according to claim 1, characterized in that: Conversion rate α p Q is the heat release corresponding to the peak temperature moment p The ratio of Q, parameter Q p and Q are obtained by integrating the curve of heat flow changing with time; let t p It is the peak moment, and its value is the abscissa of the peak value of the curve of heat flow changing with time; Q p and Q is the integral of heat flow over time on the heat flow versus time curve, Q p The integration range is t p Before time , the Q integral range is the entire curve.

5. The method for determining a reaction model based on a DSC dynamic experiment according to claim 1, characterized in that: According to RT p 2 q max / [βQ(1-α p )] = E / n, estimate the range of apparent activation energy E of the n-order reaction model substance.

6. A system for judging reaction models based on DSC dynamic experiments, characterized in that: include: A data acquisition unit, used to obtain DSC dynamic experimental results of the experimental samples at different temperature rise rates; Calculation and judgment unit, used to calculate RT at different temperature rise rates based on DSC dynamic test results p 2 q max / [βQ(1-α p )] value, if RT p 2 q max / [βQ(1-α p )] value is constant, the decomposition reaction of the experimental sample is considered to be an n-order reaction, otherwise it is an autocatalytic decomposition reaction; where R is the ideal gas constant, T p is the peak temperature, q max is the maximum heat flow value, β is the temperature rise rate, Q is the total heat release of the reaction, α p It's the conversion rate.

7. The system for determining reaction models based on DSC dynamic experiments according to claim 6, characterized in that: Also includes: Estimation unit, used to calculate the p 2 q max / [βQ(1-α p )] = E / n, estimate the range of apparent activation energy E of the n-order reaction model substance.

8. A computer system comprising a memory, a processor, and a computer program / instruction stored in the memory and executable on the processor, characterized in that: When the computer program / instructions are executed by a processor, the steps of a method for determining a reaction model based on a DSC dynamic experiment according to any one of claims 1 to 5 are implemented.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of a method for determining a reaction model based on a DSC dynamic experiment according to any one of claims 1 to 5 are implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of a method for determining a reaction model based on a DSC dynamic experiment according to any one of claims 1 to 5 are implemented.

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