Page 321 - Distillation theory

P1: JPJ/FFX P2: FCH/FFX QC: FCH/FFX T1: FCH
0521820928c08 CB644-Petlyuk-v1 June 11, 2004 20:20

8.4 Multicomponent Azeotropic Mixtures: Presynthesis 295

3

35
24
2 4 Figure 8.15. Connections between stationary points
on the binary edges of the water(1)-methanol(2)-
acetic acid(3)-acetone(4)-pyridine(5) concentration
pentahedron.

1 15 5

(2)
Therefore, top product points Reg D can only be at edge 2-4, and bottom product
(2) t(3)
points Reg at edges 1-3, 3-5. Similarly, as Fig. 8.13 shows it, regions Reg r,s of
B
trajectory tear-off from two-dimensional faces inside the pentahedron are avail-
3,5 4,2,1,3,5 4,2,1,5,3 2,4,1,5,3
t
able only at face 1-2-4 − Reg (in component order regions Reg ord , Reg ord , Reg ord
r
1,2,4 4,5
components 3,5 that are absent at this face are the heaviest), at face 1-2-3 − Reg t s
1,2,3
4,5,2,1,3
(in region Reg ord components 4,5 absent at this face are the lightest) and at face
2,4 2,4,1,3,5 2,4,1,5,3 4,2,1,3,5 4,2,1,5,3 4,2,5,1,3
t
1-3-5 − Reg (in regions − Reg ord , Reg ord , Reg ord , Reg ord , Reg ord components 2,4
s
1,3,5
absent at this face are the lightest). Therefore, bottom product points Reg B can
be located only at faces 1-2-3, 1-3-5, and top product points Reg D can be located
at face 1-2-4.
Finally, as Fig. 8.14 shows, regions of trajectory tear-off from three-dimensional
t(4)
hyperfacesReg r,s insidethepentahedronareavailableonlyathyperface1-2-3-4−
5 4,2,1,3,5 2,4,1,3,5
t
Reg (in regions Reg ord , Reg ord component 5 that is absent at this hyperface is the
r
1,2,3,4
3 4,2,1,5,3 4,2,5,1,3 4,5,2,1,3
heaviest one), at hyperface 1-2-4-5 − Reg t (in regions Reg ord ,Reg ord , Reg ord ,
r
1,2,4,5
2,4,1,5,3
Reg ord component 3 absent at this hyperface is the heaviest one), at hyperface 1-
4 4,2,1,3,5 4,2,1,5,3 4,2,5,1,3 4,5,2,1,3
t
2-3-5 − Reg (in regions Reg ord , Reg ord , Reg ord , Reg ord component 4 absent at this
s
1,2,3,5
2 2,4,1,3,5
t
hyperface is the lightest one), and at hyperface 1-3-4-5 − Reg (in regions Reg ord ,
s
1,3,4,5
2,4,1,5,3
Reg ord component 2 absent at this hyperface is the lightest one). Therefore, the
top product points Reg D can be located only at hyperfaces 1-2-3-4, 1-2-4-5, and
bottom product points Reg B can be located at hyperfaces 1-2-3-5, 1-3-4-5.
We now determine segments and possible product regions Reg D,B at the most
interesting boundary elements: at edge 1-3 (it is zeotropic in contrast to edges
2-4, 3-5), at faces 1-2-3 (it is zeotropic) and 1-2-4 (one binary azeotrope), and at
hyperfaces 1-2-3-4, 1-2-3-5, 1-2-4-5, 1-3-4-5.
We use the general algorithm of determination of possible product segments
and regions Reg D,B . The main element of this algorithm is determination of