72 Figure 7 is a similar plot for metal IMTP random packing;

Figure 8 for metal Pall rings; and Figure 9 for metal gauze BX structured packing。 A discussion of some further issues

Metal gauze structured packing in the ‘‘X’’    configuration

。c  D  。

related to curve fitting is presented in Appendix   C。

In this section, we compare predictions made with the mass-transfer correlations developed above to experiment   for

a number of different chemical systems, packing types。 All calculations were carried out with Aspen Rate Based Distil- lation  v7。2。2   In  general,  we  used  the  COUNTERCURRENT   flow

distillation  simulations。 For acid  gas removal  with  amines or

(75) with  caustic,  we  used  the  VPLUG   flow  option  (this    option

Figure 11。 Comparison of correlation predictions with experimental data for metal Pall rings。

(a) Data of Shariat and Kunesh57 for  total  reflux distillation of  cyclohexane/n-heptane at  5  psia。 (b)  Data  of  Shariat and Kunesh57  for total reflux distillation of cyclohexane/n-heptane at 5 psia。 (c) Data from Schultes9 for total reflux distillation of i-butane/n-butane at 165 psia。 (d) Data of Shariat and Kunesh57 for total reflux distillation of cyclohexane/n-heptane at 5 psia。 Correlations used in these calcula- tions: Bravo and Fair,4  Onda et al。,3  and Billet and    Schultes。5

treats the liquid phase as well mixed  and  the  vapor  as  in plug flow) and the ELECNRTL package for physical properties。 The  reader  is  informed  wherever  we  have  deviated    from

sizes。 In each case, the mass-transfer coefficient correlation developed in this article for structured packings performs as well or better than the other mass-transfer correlations examined。

these  conventions。  The  bases  of  the 65

property options are described  elsewhere。

and ELECN 66

Tables 1 and 2 contain an additional column with hHETPi

predictions   from   the  new  mass-transfer  coefficient/interfa-

Figure 10 is a comparison of total reflux binary hHETPi data for metal IMTP with simulated results for a selection of different binary mixtures and  packing  sizes。  In  each  case, the mass-transfer coefficient correlation developed in this ar- ticle for metal IMTP outperforms the other mass-transfer correlations examined。

Figure 11 is a comparison of total reflux binary hHETPi data for metal Pall rings with simulated results for a selec- tion of different binary mixtures and packing sizes。 In each case, the mass-transfer coefficient correlation developed  in this article for metal Pall rings outperforms the other mass- transfer correlations examined。

Figure 12 is a comparison of total reflux binary hHETPi data for sheet metal structured packings with simulated  results obtained for a selection of different binary mixtures and   packing

cial-area correlations developed in this article。 Clearly,  the new mass-transfer/interfacial-area correlations are an improvement over the other public-domain correlations examined here across a varied  range  of  chemical  systems and packing sizes/geometries。

Lawal et al。40 have compared pilot plant data with  the results of simulation studies on the absorption of CO2 by monoethanolamine (MEA) in a  column  packed  with IMTP 40 metal random packing。  The  pilot  plant  data  were taken by the Separations Research Program at the University of Texas, Austin。68 Lawal et  al。  reported  detailed  results  for two cases, referred to as ‘‘Case 32’’ and ‘‘Case 47。’’ Case 32 is more interesting to study because the results are strongly dependent upon the mass-transfer  correlation  selection。  In our   simulations,   we   have   used   the   Aspen   v7。0    MEA