Page 37 - Design of Simple and Robust Process Plants

20
Vent recovery
Direct feeds Cooling

~~~~~~~~~~~~~~
Cooling/
heating Container
additives
Containers with
reactor feed
Feed section Con. add batch reactor Additives Filter Floating Storage
Fig. 1.7. Flowsheet of a simple and robust batch plant.

has a post reactor. A continuous finishing was foreseen and removal of the lot tanks,
while basic product storage was provided (Figure 1.6). The system became consider-
able cheaper also as only one reactor system was required to cover full capacity ver-
sus the second generation system which had more reactor systems.
The ultimate flowsheet of a simple and robust batch process is shown in Fig-
ure 1.7. The design philosophies as discussed above were applied, and the reactor
may be used for several types of operations. All storage facilities are removed. Addi-
tives are supplied from containers before loading of the transport container for ship-
ment to the customer. Even services such as refrigeration and heating might be
obtained from suppliers who operate remotely and maintain services on the loca-
tion. Adequate control of the reactor and the feed and dosing systems is required.
The capital of the process is significantly reduced per ton of product
Simplification of a distillation train also has considerable opportunities. The rel-
ative boiling points from the components before and after the reaction are shown in
Figure 4.16 in Chapter 4. The conventional design is shown in Figure 4.17 starting
with five distillation columns. The evolution is illustrated in Figures 4.18±20. The
advantages of combining more distillatory separations in one column leads to con-
siderable savings, and this is reflected in the reduction from five columns to two ± a
real advertisement for simple design!

1.12
Summary

The plant of the 21st century has to change its design concept and is defined as:

An optimal designed safe and reliable plant, operated hands-off at the most economical
conditions.