Encontrados 9 documentos, a visualizar página 1 de 1
A-UNIFAC modelling of binary and multicomponent phase equilibria of fatty ester...
Garrido, Nuno M.; Ferreira, Olga; Lugo, Rafael; Hemptinne, Jean-Charles de; Macedo, Eugénia A.; Bottini, Susana B.The production of methyl and ethyl esters of fatty acids is of great industrial interest, considering the direct application of these esters as biodiesel. For biodiesel purification and by-products recovery processes design and optimization, the prediction of the phase behaviour of mixtures containing fatty esters, alcohols, glycerol and water is of utmost importance. In this work we show the capability of a A-...
Extension of the A-UNIFAC model to mixtures of cross- and self-associating comp...
Ferreira, Olga; Macedo, Maria E.; Bottini, Susana B.http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=4&SID=V21Di6PajaHLPoM3@AJ&page=1&doc=1&colname=WOS ; In the present work an extended UNIFAC group contribution model is used to calculate activity coefficients in solutions containing alcohols, water, carboxylic acids, esters, alkanes and aromatic hydrocarbons. The limiting expressions for the association contribution to the a...
Modeling of association effects in mixtures of carboxylic acids with associatin...
Ferreira, Olga; Fornari, Tiziana; Brignole, Esteban A.; Bottini, Susana B.http://apps.isiknowledge.com/full_record.do?product=UA&search_mode=GeneralSearch&qid=6&SID=V21Di6PajaHLPoM3@AJ&page=1&doc=1&colname=WOS ; The group contribution with association equation of state GCA-EOS has been applied to calculate thermodynamic properties of pure compounds and mixtures of carboxylic acids with paraffins, alcohols, water and gases, at low and high pressures. Two associating groups, OH and CO...
Application of the GCA-EOS model to the supercritical processing of associating...
Ferreira, Olga; Pereda, Selva; Bottini, Susana B.; Brignole, Esteban A.Supercritical processes are of interest in the fatty oil industry for a variety of applications: extraction and refining, removal of pollutants, recovery of specialties, hydrogenation of oils and derivatives, etc. Typical process mixtures include heavy compounds and gases at near critical conditions. At high pressures these asymmetric systems present a complex multiphase behaviour, difficult to model. This com...
Group contribution modeling of activity coefficients in associating solutions c...
Ferreira, Olga; Orge, Beatriz; Foco, Gloria; Bottini, Susana B.A modified UNIFAC group contribution model for the prediction of activity coefficients in associating solutions (A-UNIFAC) is applied to calculate phase equilibria in binary and ternary mixtures of associating and non-associating species, including alcohols, water, carboxylic acids, esters, alkanes, aromatic hydrocarbons and alkyl chlorides. Self- and cross-association in these mixtures is adequately described ...
Extension of UNIFAC to associating systems
Foco, Gloria; Ferreira, Olga; Brignole, Esteban A.; Bottini, Susana B.An extended UNIFAC group contribution model for the prediction of activity coefficients in associating mixtures was presented recently (Mengarelli et al.,1999). In the present work the model is applied to solutions containing alcohols, water, carboxylic acids and inert components. The residual UNIFAC local composition term is re-parameterized in order to take into account only dispersive forces between associat...
A general group contribution model for activity coefficients in associating sol...
Ferreira, Olga; Brignole, Esteban A.; Bottini, Susana B.; Macedo, Eugénia A.A modifed UNIFAC group contribution model for the prediction of activity coefficients in associating mixtures was proposed recently (Mengarelli et al., 1999). In the present work, the model is extended to carboxylic acids by defining a general associating group which allows a straightforward extension to multicomponent mixtures. The residual UNIFAC local composition term is re-parameterized in order to take int...
The extended gca-eos model for mixtures of fatty oils and derivatives
Ferreira, Olga; Fornari, Tiziana; Brignole, Esteban A.; Bottini, Susana B.The Group Contribution Equation of State GC-EOS has been satisfactory applied to the modeling of high-pressure phase equilibria of supercritical gases (CO2, propane, ethane, dimethylether) with pure triglycerides and natural vegetable oils. The GC-EOS model size-related parameter, i.e. the critical hard sphere diameter, of the high molecular weight compounds were determined by fitting infinite dilution activity...
A group contribution model for activity coefficients in associating solutions
Ferreira, Olga; Brignole, Esteban A.; Bottini, Susana B.A group contribution model is presented for the prediction of activity coefficients in associating mixtures. The new model adds an association term to the traditional UNIFAC residual and combinatorial contributions to the activity coefficients. The association term is based on Wertheim’s theory for fluids with highly directed attractive forces, as applied in the SAFT equation, and it follows the group contribut...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||