TOWARDS THE DEVELOPMENT OF A 2ND-ORDER APPROXIMATION IN ACTIVITY-COEFFICIENT MODELS BASED ON GROUP CONTRIBUTIONS

Citation
J. Abildskov et al., TOWARDS THE DEVELOPMENT OF A 2ND-ORDER APPROXIMATION IN ACTIVITY-COEFFICIENT MODELS BASED ON GROUP CONTRIBUTIONS, Fluid phase equilibria, 118(1), 1996, pp. 1-12
Citations number
11
Categorie Soggetti
Engineering, Chemical","Chemistry Physical
Journal title
ISSN journal
03783812
Volume
118
Issue
1
Year of publication
1996
Pages
1 - 12
Database
ISI
SICI code
0378-3812(1996)118:1<1:TTDOA2>2.0.ZU;2-L
Abstract
A simple modification of group contribution based models for estimatio n of liquid phase activity coefficients is proposed. The main feature of this modification is that contributions estimated from the present first-order groups in many instances are found insufficient since the first-order groups do not provide all the important molecular structur al information. Therefore, addition of second-order terms, which provi de the needed extra molecular structural information, is proposed. The scope of the new approach is demonstrated through the well-known UNIF AC model in terms of improved correlation/prediction capabilities, dis tinction between isomers and ability to overcome proximity effects.