DIPPR

The DIPPR is a research organization sponsored by the AlChE (American Institute of Chemical Engineers). Its objective is to develop a thermophysical data bank for the components most frequently encountered in the chemical industry. 

The DIPPR Pure Component Data Compilation, Numerica (TM) Version 9.2 (1994). 

Hexane, for example, is a component whose properties are well known and follow the principle of corresponding states very closely. The acentric factor recommended by the DIPPR is 0.3046 and is considered by convention not to vary with temperature. 

The acentric factor can be determined as a function of temperature by finding the exact properties supplied by the DIPPR. 

At low temperatures, using the original function/(T ) could lead to greater error. In Tables 4.11 and 4.12, the results obtained by the Soave method are compared with fitted curves published by the DIPPR for hexane and hexadecane. Note that the differences are less than 5% between the normal boiling point and the critical point but that they are greater at low temperature. The original form of the Soave equation should be used with caution when the vapor pressure of the components is less than 0.1 bar. In these conditions, it leads to underestimating the values for equilibrium coefficients for these components. 

Temperature, °C Vapor pressure DIPPR, bar abs Vapor pressure Soave, bar abs Difference SRK - DIPPR, %... 

Weight net heating values NHV of pure organic compounds at 25°C and I bar abs. Sources for hydrocarbons TRC, for others DIPPR (see chapter 4). 

DIPPR on-line database on STN, American Institute of Chemical Engineers, New York, 1992. 

Technical data. Design Institute for Physical Property Data (DIPPR) of the American Institute of Chemical Engineers (AIChE), through STN International, Columbus, Ohio, 1992. 

B. D. Smith and R. Srivastava, Thermodynamic Data for Pure Compounds, Part A, Elsevier Science Pubhshers, Amsterdam, The Netherlands, 1986 DIPPR, Project 801, Data Compilation (July 1990) R. C. Reid, J. M. Prausnitz, and B. E. Poling, The Properties of Gases and Eiquids, 4th ed.,... 

The vapoi piessuie values have been calculated at the indicated tempeiatuies using the lelationship derived from experimental data at Pennsylvania State University, and a critical review of Hterature references (5). This study is a part of the effort by the American Institute of Chemical Engineers (AIChE) to obtain accurate data through their Design Institute for Physical Property Data (DIPPR). 

The equation developed by the Design Institute for Physical Property Data (DIPPR) is another successful correlating tool for vapor pressure (4). It is an empirical extension of the Antoine equation and has two additional constants, D and E ... 

Flammability Timits. Some 1358 compounds selected from the DIPPR Compilation Pile (Peimsylvania State University, 1991 Ref. 4) have been fit for upper and lower flammabiHty limits (227). Average errors reported were 0.266% (volume) and 0.06% (volume) for upper and lower flammabiHty limits, respectively. A detailed analysis by functional group classification is included that identifies classifications with high error for several methods. 

R. Danner and T. Daubert, DIPPR 802 Data Prediction Manual, MIChE. University Park, Pa., 1986, pp. 7A1—7B2. 

P. P. Radecki, T. N. Rogers, and M. E. Mullins, Initial Development of a Method to Predict dntoine Constant Group Contributions by Simultaneous Optimisation, AIChE-DIPPR Project 912 Meeting, Michigan Technological Univeisity (June 8, 1992). 

Compiled from Daubert, T. E., R. R Danner, H. M. Sibul, and C. C. Stebbins, DIPPR Data Compilation of Pure Compound Properties, Project 801 Sponsor Release, July, 1993, Design Institute for Physical Property Data, AlChE, New York, NY and from Thermodynamics Research Center, Selected Values of Properties of Hydrocarbons and Related Compounds, Thermodynamics Research Center Hydrocarbon Project, Texas A M University, College Station, Texas (extant 1994). 

In order to ensure thermodynamic consistency, in almost all cases these properties are calculated from Tr. and the vapor pressure and liquid density correlation coefficients listed in those tables. This means that there will be slight differences between the values listed here and those in the DIPPR tables. Most of the differences are less than 1%, and almost all the rest are less than the estimated accuracy of the quantity in question. 

The Antoine equation does not fit data accurately much above the normal boiling point. Thus, as regression by computer is now standard, more accurate expressions applicable to the critical point have become usable. The entire DIPPR Compilation" is regressed with the modified RiedeP equation (2-28) with constants available for over 1500 compounds. 

The regression constants A, B, and D are determined from the nonlinear regression of available data, while C is usually taken as the critical temperature. The hquid density decreases approximately linearly from the triple point to the normal boiling point and then nonhnearly to the critical density (the reciprocal of the critical volume). A few compounds such as water cannot be fit with this equation over the entire range of temperature. Liquid density data to be regressed should be at atmospheric pressure up to the normal boihng point, above which saturated liquid data should be used. Constants for 1500 compounds are given in the DIPPR compilation. 

Second virial coefficients, B, are a fnncBon of temperature and are available for about 1500 compounds in the DIPPR compilaOond The second virial coefficient can be regressed from experimental PX T data or can be reasonably and accurately predicted. Tsonoponlos proposed a predicOon method for nonpolar compounds that requires the criOcal temperature, critical pressure, and acentric factor Equations (2-68) through (2-70) describe the method. 

Constants for about 1500 compounds for both viscosities are available in the DIPPR compilation. ... 

Flash points, lower and upper flammability limits, and autoignition temperatures are the three properties used to indicate safe operating limits of temperature when processing organic materials. Prediction methods are somewhat erratic, but, together with comparisons with reliable experimental values for families or similar compounds, they are valuable in setting a conservative value for each of the properties. The DIPPR compilation includes evaluated values for over 1000 common organics. Detailed examples of most of the methods discussed are available in Danner and Daubert."... 

Literature (e.g., Pedley s Handbook) or as determined. Perry s Chemical Engineers Handbook, DIPPR, CRC Handbook of Chemistry and Physics... 

DIPPR Design Institute for Physical Property Data... 

The model contains a surface energy method for parameterizing winds and turbulence near the ground. Its chemical database library has physical properties (seven types, three temperature dependent) for 190 chemical compounds obtained from the DIPPR" database. Physical property data for any of the over 900 chemicals in DIPPR can be incorporated into the model, as needed. The model computes hazard zones and related health consequences. An option is provided to account for the accident frequency and chemical release probability from transportation of hazardous material containers. When coupled with preprocessed historical meteorology and population den.sitie.s, it provides quantitative risk estimates. The model is not capable of simulating dense-gas behavior. 

Although the code is based on well-recognized models referenced in the literature, some of the underlying models are based on "older" theory which has since been improved. The code does not treat complex terrain or chemical reactivity other than ammonia and water. The chemical database in the code is a subset of the AIChE s DIPPR database. The user may not modify or supplement the database and a fee is charged for each chemical added to the standard database distributed with the code. The code costs 20,000 and requires a vendor supplied security key in the parallel port before use. 

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