Page 174 - Design of Simple and Robust Process Plants

5.3 Combination of Process Functions 159

lights
lights feed
unconverted
Reactor
feed reactant reactor
crude
crude reactor feed
product
Reactor

Products
Products

Fig. 5.12. Two separate columns versus one thermally coupled column.

crude reactor
Products
product
Products
Reactor feed
feed reactor
crude
feed
Reactor

Tar Unconverted
reactant
Tar
Fig. 5.13. Two separate columns versus one thermally coupled column.

Krupp Uhde). In this industrial example three columns are replaced by one column.
The thermal coupling of two distillation columns is also shown in Figures 5.12 and
13. Here, two columns ± one in front of a reactor and one after the reactor ± are
combined in one column. New concepts apply to coupled distillation separations, if
the situation permits. For more details, see Section 5.6.1.5.

5.3.3
Extraction, Evaporation, Extrusion

Conventional extraction was carried out in mixing vessels, followed by a gravity
separator (Figure 5.14). Due to this rather complex configuration the number of
stages were minimized. One improvement to be realized was to replace the mixing
vessels with static mixers, although pumps were also used as mixers. Another