Thermodynamics Research Center

The Themodynamics Research Center Group is one of the oldest data research centers in the United States. For over 60 years, TRC has produced a great number of the periodical compilations and electronic databases that have become a major source of recommended data for scientific research and industrial process design, for both pure materials and mixtures.

Tasks

Located in Boulder, CO, TRC Group performs several functions related to providing state-of-the-art thermodynamic data:

• compiles and evaluates experimental data
• develops tools and standards for archival and dissemination of thermodynamic data, especially critically evaluated data
• develops electronic database products
• maintains a web-repository of published data in ThermoML — an XML format developed by TRC for the representation of thermodynamic data

About TRC

The Thermodynamics Research Center collects and evaluates thermophysical and thermochemical data (more than 100 properties) of organic compounds and develops large thermophysical property databases and database-management systems. The Center also develops a concept and process of "dynamic evaluation" of thermophysical and thermochemical property data to provide critical data evaluations "on-demand". The Center develops software tools for global data collection, storage, exchange, and dissemination via the TRC Data Entry Facility and develops software protocols for the TRC Data Quality Assurance program. TRC is developing the concept of Global Information Systems in Science and implementing it in application to the field of Thermodynamics. 

Critically Evaluated Data

An important and useful aspect of our work here at TRC, and of the Thermophysical Properties Division of NIST as a whole, is to provide critically evaluated data. Critical evaluation is a process of analyzing all available experimental data for a given property to arrive at recommended values together with estimates of uncertainty, providing a highly useful form of thermodynamic data for our customers. The analysis is based on intercomparisons, interpolation, extrapolation,and correlation of the original experimental data collected at TRC. Data are evaluated for thermodynamic consistency using fundamental thermodynamic principles, including consistency checks between data and correlations for related properties. While automated as much as possible, this process is overseen by experts with a great deal of experience in the field of thermodynamic data. Professional staff are responsible for the evaluation of each set of data that is committed to the archive.

For many years TRC has published 2 series of periodicals containing evaluated data for pure compounds (TRC Tables - Hydrocarbons and TRC Tables - Non-Hydrocarbons.)

We recently completed development of a web version of the TRC Tables. This product is called Web Thermo Tables (WTT), and comes in both a Professional Edition and a Lite Edition. Both are available by subscription through the NIST Standard Reference Data program (SRD). WTT - Professional Edition represents a complete collection of critically evaluated thermodynamic property data primarily for pure organic compounds. As of September, 2007, WTT contains information on 7765 compounds. WTT - Lite Edition represents a collection of critically evaluated thermodynamic property data for 150 commonly-used (primarily organic) pure compounds.

A critical resource is our extensive in-house collection of published thermodynamic and thermophysical properties, the SOURCE data system. All of the data catalogued for critical evaluation by TRC are stored in this data system. An important aspect of TRC's mission is to continue to expand this collection to make it as complete a repository as possible for all published thermodynamic and thermophysical property data.