Page 34 - Design of Simple and Robust Process Plants

1.11 Overall Example of Process Design 17
2. How can this be implemented in a project in order to achieve high-quality
designs and operation?

These questions will be addressed in Chapter 10, where the operation and continu-
ous improvement of an existing plant is discussed, notably with regard to the follow-
ing points:
. process capacity upgrading;
. process reliability and availability;
. quality of operation;
. operation optimization; and
. identification of design improvements.
The efficient design of high-quality plants is presented along two lines: (i) the ele-
ments required to design a good work-process (methodology) for process design;
and (ii) the essentials to assure the quality of a process design.
In order to achieve quality designs the chemical industry introduced Value
Improvement Practices (VIPs), the implementation of which during the design is
crucial for the quality. The VIPs might be different for different companies, but
incorporate the following topics:

. technology selection;
. waste minimization;
. process simplification;
. process and energy optimization;
. reliability modeling;
. design to capacity;
. maintenance;
. construction; and
. value engineering.
Functional analysis is an essential technique for the implementation of process sim-
plification. The technique, which was developed as a tool for value engineering
(Snodgrass and Kasi, 1986), began in the 1970s and 1980s to force the weapons
industry in the U.S.A. to deliver at lower cost. The same technique can be applied to
the introduction of process simplification in the process industry, and is incorpo-
rated in the VIPs, simplification and value engineering.

1.11
Overall Example of Process Design

Having briefly described these design philosophies and techniques, an example of
the evolution of a batch process from its initial design, and its development to a
simple and robust design, is provided. A typical batch process is illustrated in Fig-
ure 1.4, as it was scaled-up from the preparation at laboratory scale. In this example
the chemicals are introduced in the reactor vessel at the beginning of the planned