Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Binary systems, parameterization

In line with single phase flows, the diffusive flux, is commonly parameterized adopting Tick s law for binary systems, = —pkDs k,s-... [Pg.385]

For process simulation, the thermodynamic properties of the quaternary mixture 1-hexanol + acetic add + hexyl acetate + water have to be known. The vapor-Uquid equilibrium model of that quaternary mixture is, as usual, parameterized based on information from the binary systems alone. There are six binary mixtures for a quaternary mixture, two of which are reactive in our example. The special challenges in the experimental determination of phase equilibria in reactive systems will be discussed later. Using typical G models, at least 12 parameters have to be adjusted to experimental binary data or estimated. Additionally, at least the... [Pg.75]

A helpful but rarely used tool for deciding whether accurate information on a given binary system is needed for the design of a certain separation is provided by sensitivity analysis. An example for such an analysis of the hexyl acetate RD process shown in Fig. 4.4 is given in Fig. 4.5. The basis of the sensitivity analysis is a given operating point of the RD column and a fully parameterized process model. In our case the NRTL model with two adjustable parameters per binary system was used to describe liquid-phase non-idealities in that model. Parameters for systems, for which no experimental data was available were estimated with UNIFAC in a first step. [Pg.76]

Lastly, the COMB poetical is fit to the binary system with multiple phases. Similar to the parameterization process for a pure system, the potential starts with fitting the pairwise terms to the phase orders and charge of a variety of binary systems, which is followed by fitting the parameters in many-body terms to the properties of the binary system. The parameters involved in the binary system are listed in Table 7.4. [Pg.264]

In some cases it is possible to fiilly parameterize a given system from experimental input, as will be done in every example presented in Sec. 3. However, the determination of complete primary parameter sets for every possible element in every possible reference state, as well as the associated secondary sets for the concentration-dependent binary cases, is not an easy task as, in most cases, it would require input that is not available from experiment. Once again, this issue can be properly and systematically dealt with by means of first-principles calculations. For example, reference states can differ from the ground state symmetries of the participating elements in the alloy. In those situations, it is strictly neces-... [Pg.34]


See other pages where Binary systems, parameterization is mentioned: [Pg.2075]    [Pg.381]    [Pg.164]    [Pg.262]    [Pg.262]    [Pg.264]    [Pg.145]    [Pg.14]    [Pg.79]    [Pg.26]    [Pg.52]   
See also in sourсe #XX -- [ Pg.254 ]




SEARCH



Binary systems

Parameterization

Parameterized

Parameterizing

© 2024 chempedia.info