Kinetic model for process, where Peaks (marked) belong to the different reaction steps depending on the heating rate. Model-free analysis fails for this situation. Only NETZSCH Thermokinetics with model based analysis works correctly.
Description

Description

Thermokinetics is a software for the kinetic analysis of thermal measurements, including model-free and model based kinetic analysis.

The kinetic analysis allows to find the set of kinetic parameters e.g. number of steps, contribution of each step to the total effect of the process such as step enthalpy or step mass loss; reaction type, activation energy and reaction order for each step.

Then this information will be used for predictions of reaction progress for given temperature conditions or optimization of temperatures to get the desired reaction rate and product concentrations. The predictions can be done for one or several isothermal measurements, for dynamic measurements like heating, for isothermal or dynamic segment with daily temperature oscillations and for any sequence from such temperature segments.

What you get

What you get

Kinetic parameters like:

  • Activation energy
  • Pre-exponential factor
  • order of reactions
  • order of autocatalysis
  • number of reaction steps
  • reaction type for each reaction step

Results are:

  • Optimized parameters including standard errors
  • F-test regarding the fit quality
  • F-test regarding significance of an additional step
  • Graphic presentation

As soon as kinetic analysis is done and kinetic model with all kinetic parameters is found, this model can be used for the solving of the main tasks of Thermokinetics: Prediction and Optimization.

Predictions: Isothermal and on the Base of a User Defined Temperature Program

  • Isothermal prediction of signal; Dynamic prediction of signal
  • Tabular report of signal and degree of reaction versus time for a set of temperatures
  • Isothermal and dynamic predictions of degree of reaction
  • Isothermal and dynamic predictions of formal reactants

Optimization: find temperature program for given system behavior

  • It is the typical problem for the production process when the temperature program must be found for optimal time and optimal quality. Thermokinetics software allows to find the temperature conditions to archive desired reaction rate or desired product concentrations changing during production process.
    Examples: RCS (Rate controlled sintering) and RCM (rate controlled mass loss).
    The software saves time and finds desired temperature program:

    • for given reaction rate
    • for given output signal
    • for given rate of final product production
What you need

What you need

Measurements data sets for analysis, for example:

  • Set of dynamic measurements with different heating rates
  • Set of isothermal measurements with different temperatures
  • Set of both dynamic and isothermal measurements
  • Adiabatic measurements with different phi factors.

The data for analysis can be measured by NETZSCH instruments or by instruments of other manufactures. Data import from different instruments is possible via the general interface ASCII file.

Data types:

  • Thermogravimetry (TGA: mass change)
  • Differential Scanning Calorimetry (DSC: Heat flow, DTA: Temperature difference)
  • Accelerating Rate Calorimetry (ARC: Temperature, pressure, APTAC: temperature)
  • Multiple Mode Calorimetry (MMC: Temperature, Heating rate, pressure, heat generation)
  • Mass Spectrometry (MS: ion current)
  • Dilatometry (DIL: length change)
  • Rheometry and its special Variant Vulcametry (RHEO, VULC: torque, viscosity)
  • Dielectric analysis (DEA: ion viscosity)
  • Free source (any signal type changing during chemical reaction)
Calculation Methods

Calculation Methods

There are two different approaches for kinetic analysis of chemical processes: Model-free and Model-based.

The Model-free is quite simple and therefore is wide-used. The model-free approach can only find activation energy of the process without any parallel or competitive steps, and then make predictions.
Drawback: it cannot answer the question about number of steps, their contribution to the total effect of reaction or about reaction order for each step.

The Model-based analysis is based on the assumption about kinetic model of the process, uses powerful mathematics to solve the system of differential equations and make statistical comparison of used models and therefore can answer all these questions.

Model Free kinetic analysis methods:

  • ASTM E698
  • Friedman
  • Ozawa-Flynn-Wall
  • ASTM E1641
  • ASTM E 2890
  • Kissinger, Akahira and Sunose (KAS)

Model-based kinetic analysis methods:

  • Single-step analysis (Linear regression)
  • Multiple Step analysis (Nonlinear regression)
Application Fields

Application Fields

  • food, medicines, recycling
  • ceramics, metallurgy
  • polymers, plastics
  • epoxy resins
  • automotive industry
  • air plane production
  • building of bridges
  • road construction
  • safety analysis, explosives.
Application Examples

Application Examples

Applications using Rheometry/Vulcametry

Cross Linking of Powder Paint
Vulcanization of Natural Rubber

What's new in Thermokinetics 3.2

What's new in Thermokinetics 3.2

  • Evaluation according ASTM E 2890
    Evaluation according to ASTM E 2890 allows for calculation of activation energy and pre-exponential factor from the temperatures of maximum reaction rate for different heating rates.  
  • Evaluation according to Kissinger, Akahira and Sunose (KAS)
    The method of Kissinger, Akahira and Sunose is another isoconversional approach similar to that of Ozawa, Flynn and Wall considering, however, the Kissinger-Akahira-Sunose equation.  
  • Updates
    Automatic or manual update of the newest version of Thermokinetics from the Internet.
  • Reaction rates
    Graph of Reaction rates for dynamic predictions for up to 4-step reactions.  
  • Correction parameters for tau-R
    New file for correction parameters Tau-R.kcr for tau-R corrected DSC data from Proteus.  
  • Export of model-free analysis to ASCII
    • Export of Osawa-Flynn-Wall graph to ASCII
    • Export of Friedman graph to ASCII
    • Export of ASTM E968 graph to ASCII  
  • Kinetic models
    New kinetic models are added
Literature

Literature

Predictions of conversion for isothermal curing of epoxy resin
Kinetic model for ion viscosity (DEA measurement) for curing of epoxy
Time-Temperature-Transition diagram for curing with diffusion control
Kinetic model for Sintering of ceramic Si3N4
Optimization of temperature for constant length change rate 0.1%/min during RCS: rate controlled sintering
Prediction of sintering process for given temperature program
Temperature prediction for adiabatic conditions with 5 initial temperatures from 100 to 120°C: DTBP
Temperature prediction for adiabatic conditions with 5 different Phi factors from 1.5 to 2.5, step 0.2, DTBP
Measured data for DTBP in TMR view