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ThermoData Engine (TDE)

NIST TDE 103a - Pure Compounds

NIST TDE 103b - Pure Compounds, Binary Mixtures, Ternary Mixtures and Chemical Reactions

Expert Thermodynamic Data Correlation, Evaluation, and Prediction


Purpose

The purpose of the ThermoData Engine software is to provide critically evaluated thermodynamic and transport property data based on the principles of dynamic data evaluation.

Critical evaluation is based on:

  1. Published experimental data stored in a program database
  2. Predicted values based on molecular structure
  3. User supplied data (optional)

The principles upon which the ThermoData Engine software are based are fully discussed in the following four articles: ThermoData Engine (TDE): Software Implementation of the Dynamic Data Evaluation Concept. [J. Chem. Inf. Model., 45, 816-838, 2005], ThermoData Engine (TDE): Software Implementation of the Dynamic Data Evaluation Concept. 2. Equations of State on Demand and Dynamic Updates over the Web. [J. Chem. Inf. Model., 47, 1713-1754, 2007], ThermoData Engine (TDE): Software Implementation of the Dynamic Data Evaluation Concept. 3. Binary Mixtures. [J. Chem. Inf. Model., 49, 503-517, 2009], and ThermoData Engine (TDE): Software Implementation of the Dynamic Data Evaluation Concept. 4. Chemical Reactions. [J. Chem. Inf. Model., 49, 2883-2896, 2009]. The first paper describes the foundations of TDE. The second paper describes the extension of TDE for dynamic Equation of State evaluation and online updating. The third and fourth papers describe the expansion of the Dynamic Data Evaluation concept to binary mixtures and chemical reactions, respectively.


Program Outputs and Formats

The program output is evaluated data in the form of:
  1. Parameters for fitted equations with covariance matrices
  2. Tables of recommended values with uncertainties.
TDE Program output can be saved as a plain text file or in ThermoML format (See http://trc.nist.gov/ThermoML.html).


Overview

ThermoData Engine is the first product fully implementing all major principles of the concept of dynamic data evaluation formulated at NIST/TRC. This concept requires the development of large electronic databases capable of storing essentially all 'raw' experimental data known to date with detailed descriptions of relevant metadata and uncertainties. The combination of these databases with expert software designed to generate recommended data based on available 'raw' experimental data and their uncertainties leads to the possibility of producing data compilations automatically 'to order' forming a dynamic data infrastructure. The NIST/TRC SOURCE data archival system, currently containing more than 4.8 million experimental data points, is used in conjunction with ThermoData Engine as a comprehensive storage facility for experimental thermophysical and thermochemical property data.

The ThermoData Engine (TDE) software incorporates all major stages of the concept implementation, including data retrieval, grouping, normalization, sorting, consistency enforcement, fitting, and prediction for all major thermophysical properties. The ThermoData Engine fills the gaps in experimental data by deployment of the automated group-contribution and corresponding-states property prediction, emphasizes enforcement of consistency between related properties (including those obtained from predictions), provides for flexibility in selection of default data models depending on the particular data scenario, incorporates a large variety of models for secondary fitting, and allows saving of critically evaluated data in the ThermoML format. TDE supports several equations of state for pure compounds (original and modified volume-translated Peng-Robinson, Sanchez-Lacombe, PC-SAFT, and Span-Wagner) and allows user to fit their parameters to experimental and predicted data. Enthalpies of formation are evaluated on the basis of stored experimental enthalpies of combustion and modified Benson group-contribution method. ThermoML output assures compatibility of the ThermoData Engine with any engineering application equipped with a ThermoML software 'reader'. Periodical Web updates of the local TDE-SOURCE database maintain its up-to-date status, providing new data to users of TDE soon after original publication in the literature.

TDE supports evaluation of the thermodynamic properties of chemical reactions such as enthalpies, entropies, Gibbs free energies, and equilibrium constants based on available experimental data as well as group contribution methods. The stored experimental data include calorimetric values for more than 4,000 reactions and reaction equilibrium data for more than 1,500 reactions.

TDE provides functionality for determination of chemical systems possessing required ranges of thermophysical properties to support the user's activities in chemical product design. This functionality is available for pure compounds, binary mixtures, and ternary mixtures. TDE also implements an algorithmic approach to aid users in experiment planning based on the accumulated body of knowledge stored in NIST/TRC SOURCE as well as the TDE prediction models.

NIST ThermoData Engine 103a - Pure Compounds

The scope of the NIST Standard Reference Database 103a is pure compounds only. The ThermoData Engine (TDE) software incorporates all major stages of the concept implementation, including data retrieval, grouping, normalization, sorting, consistency enforcement, fitting, and prediction for all major thermophysical properties (about 50 properties total) including density, vapor pressure, heat capacity, enthalpies of phase transitions, critical properties, melting and boiling points, etc.

You may browse the Users' Guide to see how this database works.

NIST ThermoData Engine 103b - Pure Compounds, Binary Mixtures, and Chemical Reactions

The scope of the NIST Standard Reference Database 103b is pure compounds, binary mixtures, and chemical reactions. The ThermoData Engine (TDE) software incorporates all major stages of the concept implementation, including data retrieval, grouping, normalization, sorting, consistency enforcement, fitting, and prediction for all major thermophysical properties (about 120 properties total) including density, vapor pressure, heat capacity, enthalpies of phase transitions, critical properties, melting and boiling points, etc.

TDE provides access to single-phase thermodynamic and transport property data, VLE, LLE, and SLE data for over 40,000 binary mixtures and 11,000 ternary mixtures, and does automated evaluation of most of those properties. Certain properties such as densities, critical, and transport properties are described by special fitting equations; phase equilibria data are described by activity coefficient models selected by the user from the set of supported models: Margules, NRTL, Redlich-Kister, UNIQUAC, van Laar, and Wilson. UNIFAC predictions are generated for mixtures covered by the UNIFAC method, including those for which experimental data are currently not available. Phase diagrams, isotherms, and isobars based on those models can be calculated and drawn for the user's convenience. Proprietary data can be entered for inclusion in the evaluation, and the user can influence the evaluation process by changing relative data weights or by rejecting particular data sets.

TDE supports evaluation of the thermodynamic properties of chemical reactions such as enthalpies, entropies, Gibbs free energies, and equilibrium constants based on available experimental data as well as group contribution methods. The stored experimental data include calorimetric values for more than 4,000 reactions and reaction equilibrium data for more than 1,500 reactions.

TDE provides functionality for determination of chemical systems possessing required ranges of thermophysical properties to support the user's activities in chemical product design. This functionality is available for pure compounds, binary mixtures, and ternary mixtures. TDE also implements an algorithmic approach to aid users in experiment planning based on the accumulated body of knowledge stored in NIST/TRC SOURCE as well as the TDE prediction models.

You may browse the Users' Guide to see how this database works.