UNIFAC. Documentation. DDBSP Dortmund Data Bank Software Package

Transcription

1 UNIFAC Documentaton DDBSP Dortmund Data Ban Software Pacage DDBST Dortmund Data Ban Software & Separaton Technology GmbH Mare-Cure-Straße 10 D Oldenburg Tel.: Fax: E-Mal: support@ddbst.com Web:

2 Table of Contents Introducton...3 Tutoral...3 Buldng a System...4 Checng Parameter Avalablty...6 Calculaton...9 Isothermal Calculaton over a Concentraton Range...9 Calculaton at Constant Compostons over a Temperature Range...11 Result Grd...11 Actvty Coeffcent Dagram...12 The Menus...12 Appendx...13 UNIFAC...13 Table of Fgures Fgure 1: UNIFAC Graphcal User Interface...4 Fgure 2: Selecton...5 Fgure 3: Lst...5 Fgure 4: Group Assgnment Detals...6 Fgure 5: Parameter Avalablty...7 Fgure 6: Calculaton Settngs...9 Fgure 7: Calculaton at Constant Temperature...9 Fgure 8: Composton Settngs...10 Fgure 9: Specal Compostons...10 Fgure 10: Calculaton Settng for Constant Compostons...11 Fgure 11: Result Grd...11 Fgure 12: Result Grd wth LLE Calculaton...11 Fgure 13: Temperature-dependent Actvty Coeffcents...12 UNIFAC Page 2 of 14

3 Introducton Ths software allows calculatng actvty coeffcents, heats of mxng, and excess heat capacty by the actvty coeffcent models UNIFAC 1 and modfed UNIFAC (Dortmund) 2 for mxtures wth up to ffty components. If the LLE extenson lcense s avalable t s also possble to calculate the lqud-lqud equlbrum for bnary and ternary systems. The software s an ntegral part of the Dortmund Data Ban software pacage and uses the component, the groups assgnment, and other tools from ths pacage. The pacage therefore ncludes 1. the man calculaton program (descrbed here) 2. a component selecton tool (descrbed n Management.pdf ) 3. a component edtng tool (descrbed n Management.pdf ) 4. a UNIFAC nteracton parameter edtor (descrbed n GC Model Parameters.pdf ) 5. a DDB confguraton edtng tool (descrbed n DDBConfguraton.pdf ) The software comes wth a lst of more than components from the man DDB component lst and approx of them have a UNIFAC group assgnment and about have a group assgnment for modfed UNIFAC (Dortmund). For most components the DDB provdes CAS regstry numbers (24250), emprcal formula molecular weghts (almost all). All other components are applcable n both methods (e. g. salts, metals and metal complexes, etc.). The latest UNIFAC parameters have been publshed n , the latest parameter for mod. UNIFAC (Dortmund) have been publshed , and 2011 (onc lquds) 6. Most current parameters can be obtaned from the UNIFAC Consortum. Tutoral Ths tutoral shows all functons nsde the man calculaton software. Addtonal PDFs are avalable for edtng, addng, and searchng components, as well as for modfyng/understandng the DDB confguraton, and the nteracton parameter edtor. 1 Fredenslund A., Jones R.L., Prausntz J.M., Group-Contrbuton Estmaton of Actvty Coeffcents n Nondeal Lqud Mxtures, AIChE J., 21(6), , Wedlch U., Gmehlng J., A Modfed UNIFAC Model. 1. Predcton of VLE, he, and γ, Ind. Eng. Chem. Res., 26(7), , Wttg R., Lohmann J., Gmehlng J., Vapor-Lqud Equlbra by UNIFAC Group Contrbuton. 6. Revson and Extenson, Ind. Eng. Chem. Res., 42(1), , Gmehlng J., Wttg R., Lohmann J., Joh R., A Modfed UNIFAC (Dortmund) Model. 4. Revson and Extenson, Ind. Eng. Chem. Res., 41(6), , Jaob A., Grensemann H., Lohmann J., Gmehlng J., Further Development of Modfed UNIFAC (Dortmund): Revson and Extenson 5, Ind. Eng. Chem. Res., 45(23), , Nebg S., Gmehlng J., Predcton of phase equlbra and excess propertes for systems wth onc lquds usng modfed UNIFAC: Typcal results and present status of the modfed UNIFAC matrx for onc lquds, Flud Phase Equlb., 302(1-2), , 2011 UNIFAC Page 3 of 14

4 Buldng a System System (Lst of s) Add s Fgure 1: UNIFAC Graphcal User Interface A system contans of several pure components. can be added by the Add button. The calls the standard DDB component selecton pacage whch s descrbed n detals n a separate PDF ( Management, Chapter 9). The dalog allows searchng for names, formulas, CAS regstry numbers, and many more crtera. UNIFAC Page 4 of 14

5 Search Lst Fgure 2: Selecton The component lst shown s the complete lst of components avalable n the Dortmund Data Ban. It ncludes also many components for whch no group assgnments are avalable. After a component has been selected (by a double-clc or by ) the component s added to the component lst. Group Assgnments Fgure 3: Lst Mssng Group Assgnment Ths lst dsplays the DDB nternal number, an Englsh name, the emprcal formula, the molecular weght, and both the group assgnments for UNIFAC and modfed UNIFAC (Dortmund). If a group assgnment s not gven a n.a. s wrtten. Sngle components can be removed by double-clcng the lne, the complete lst can be cleared by clcng the Remove All button. The system table has a context menu whch allows 1. Remove all components UNIFAC Page 5 of 14

6 2. Remove the selected component 3. Copyng, prntng, and savng the component lst 4. Auto-sze the columns of the table 5. Dsplay detals of the group assgnment Fgure 4: Group Assgnment Detals The normal dsplay n the component lst only dsplays the sub groups of the components and ths dalog adds nformaton about the man groups. Checng Parameter Avalablty UNIFAC needs the component specfc group assgnment and nteracton parameters between all man groups present n the current mxture. The dalog has two pages: 1. The frst page only dsplays f all parameters are avalable UNIFAC Page 6 of 14

7 Fgure 5: Parameter Avalablty 2. The second page gves detals about the group assgnment for all components and all man group nteractons. The example shows that for the gven system UNIFAC can be used but modfed UNIFAC (Dortmund) wll fal because of a mssng nteracton parameter. UNIFAC Page 7 of 14

8 UNIFAC 11: Ethanol Subgroups: 1 (CH3 ) 2 (CH2 ) 14 (OH ) 12: Dethyl ether Subgroups: 1 (CH3 ) 2 (CH2 ) 25 (OCH2 ) 17: Anlne Subgroups: 9 (ACH ) 36 (ACNH2 ) 15: Formc acd Subgroups: 43 (HCOOH ) Lst of Man Groups Mangroups: 1 (CH2 ) 3 (ACH ) 5 (OH ) 13 (CH2O ) 17 (ACNH2 ) 20 (COOH ) Interacton parameters 1-3: 1 parameter/s 1-5: 1 parameter/s 1-13: 1 parameter/s 1-17: 1 parameter/s 1-20: 1 parameter/s 3-5: 1 parameter/s 3-13: 1 parameter/s 3-17: 1 parameter/s 3-20: 1 parameter/s 5-13: 1 parameter/s 5-17: 1 parameter/s 5-20: 1 parameter/s 13-17: 1 parameter/s 13-20: 1 parameter/s 17-20: 1 parameter/s System has all parameters avalable. mod. UNIFAC (Dortmund) 11: Ethanol Subgroups: 1 (CH3 ) 2 (CH2 ) 14 (OH (P) ) 12: Dethyl ether Subgroups: 2 (CH2 ) 1 (CH3 ) 25 (OCH2 ) 17: Anlne Subgroups: 9 (ACH ) 36 (ACNH2 ) 15: Formc acd Subgroups: 43 (HCOOH ) Lst of Man Groups Mangroups: 1 (CH2) 3 (ACH) 5 (OH) 13 (CH2O) 17 (ACNH2) 44 (HCOOH) Interacton parameters 1-3: 2 parameter/s 1-5: 3 parameter/s 1-13: 2 parameter/s 1-17: 3 parameter/s 1-44: 1 parameter/s 3-5: 3 parameter/s UNIFAC Page 8 of 14

9 3-13: 2 parameter/s 3-17: 3 parameter/s 3-44: 3 parameter/s 5-13: 3 parameter/s 5-17: 3 parameter/s 5-44: 0 parameter/s 13-17: 2 parameter/s 13-44: 1 parameter/s 17-44: 0 parameter/s Parameters are mssng. Calculaton Fgure 6: Calculaton Settngs Isothermal Calculaton over a Concentraton Range For a constant temperature t s possble to enter compostons manually or let the program calculate some auto-dstrbuted composton ponts. Fgure 7: Calculaton at Constant Temperature UNIFAC Page 9 of 14

10 The Set Compostons button opens a dalog where compostons can be created ( Create Data Ponts ). In ths dalog t s possble to enter compostons drectly n the data grd and t allows creatng data ponts over a composton range. Specal case le constant compostons or composton ratos for sngle or few components are also supported. The composton grd can be coped to the Wndows clpboard as well as data can be pasted from the clpboard. Ths allows creatng and managng compostons outsde ths program (maybe n Mcrosoft Excel or OpenOffce Calc). Compostons can also be saved to and restored ( Open ) from fles. The number of possble data ponts s lmted to Data Grd Fgure 8: Composton Settngs Specal compostons can be constant compostons for sngle components or specal composton ratos (specfed by nteger values le 4 and 5 four a 4 / 5 rato) for a lst of components. Fgure 9: Specal Compostons UNIFAC Page 10 of 14

11 Calculaton at Constant Compostons over a Temperature Range Fgure 10: Calculaton Settng for Constant Compostons Ths calculaton type allows the specfcaton of a sngle composton lne and a temperature range. The composton can be entered as mole fractons and as weght fractons. Result Grd Fgure 11: Result Grd The result grd shows all gven compostons and the wanted temperatures frst followed by the calculated actvty coeffcents, the heat of mxng and the excess heat capacty. Fgure 12: Result Grd wth LLE Calculaton If the LLE calculaton s actve the ntal concentratons are treated as feed. The result grd wll then be extended by two phase columns for each component and two actvty coeffcent/he/cpe columns for the second phase. The addtonal columns wll be present even f no LLE was found. The table can be saved as Mcrosoft Excel ( xls ) fle ( clpboard ( ). ) or coped to the Wndows UNIFAC Page 11 of 14

12 Actvty Coeffcent Dagram In case of the calculaton at a fxed sngle composton at dfferent temperatures a dagram wth the temperature-dependent actvty coeffcents s dsplayed. Fgure 13: Temperature-dependent Actvty Coeffcents The Menus lsts are fles contanng raw data set numbers. These fle have the extenson stl. The system grd can also be saved as a comma separated fle whch can be loaded n spread The system grd (component lst) can be coped and prnted. s starts the Edtor (descrbed n Management.pdf ) Show Hnts actvates addtonal hnts for many tems on the form. Interacton Parameter Matrx starts the parameter edtor (descrbed n GC Model Parameters.pdf ) UNIFAC Page 12 of 14

13 sheet programs. DDB Confguraton starts the confguraton program (descrbed n DDBConfguraton.pdf ) Appendx UNIFAC The UNIFAC group contrbuton model 7 has been developed to estmate the real vapor-lqud equlbrum behavor. In a group contrbuton model the mxture s not seen as a mxture of components but as a mxture of groups. The large advantage s that the number of structural groups s much smaller (dozens) than the number of components (mllons). Ths means that t s possble to calculate most systems of commercal nterest wth very few group nformaton. UNIFAC s based on the UNIQUAC equaton. Therefore actvty coeffcents are calculated from two terms, ln ln. C R ln The combnatoral part s calculated n the same manner as n UNIQUAC, wth ln C 1V lnv V 5q 1 F V ln F V r r x and F q q x. For the calculaton of the combnatoral part only the relatve van der Waals volume r and surface q together wth the mole fractons x are needed. The van der Waals volume and surface can be calculated from group volumes and surfaces, ( ) r R ( ) q Q 7 Gmehlng J.,Kolbe B., Thermodynam, Verlag Cheme, Wenhem (1987) UNIFAC Page 13 of 14

14 wth () as the number of structural groups of type n the molecule. The resdual part has to be calculated from the group actvty coeffcents, R ( ln ) ln ln The concentraton dependency of the group actvty coeffcents n the mxture (and n the pure component () The surface contrbuton m Q n m Q X n m X n ) must be calculated n analogy to the UNIQUAC equaton, ( ) mm ln Q 1 ln mm. m m n n n m and the mole fracton. X m of the group s defned by X m n m x n, x and the parameter nm s defned as nm e anm T wth a nm as group nteracton parameters between the groups n and m. Modfed UNIFAC (Dortmund) uses temperature-dependent nteracton parameters: nm e 2 anm bnmt cnm T T T T UNIFAC Page 14 of 14