Page 136 - Plant design and economics for chemical engineers

COMPUTER-AIDED DESIGN 111

engineering) and the integration of these units into complete, consistent, effi-
cient processes to produce chemical products. This chapter gives a brief intro-
duction to computer software useful for process and plant design and to
approaches in design that take advantage of the capabilities of computers and
software.
An engineer may write a programming language code to solve a particular
design problem. Before the explosive growth of software, this commonly was
done. There is still a place for it when appropriate software is not available or
as a learning technique. An example of code written specifically to solve a
chemical-reactor-design problem is shown, in three different programming lan-
guages, in Chap. 16. (Chemical reactors, because of the great variety of reactor
types, reaction kinetics, and specific design requirements, constitute a process-
unit type for which available software may not be appropriate.) Because
program writing and debugging is usually quite time consuming, it is recom-
mended that available software be used and that a specific design program be
written only after determining that appropriate software is not available. Many
programs useful for chemical engineers have been published.?
Spread-sheet software has become an indispensible tool to engineers
because of the availability on personal computers, ease of use, and adaptability
to many types of problems. An example of spread-sheet application to a
problem typical of chemical process design is presented later in this chapter.
Hundreds, even thousands, of programs have been written to solve prob-
lems commonly encountered by chemical engineers. Many of these have become
available for purchase. In turn, many of these programs are for the design of
individual units of chemical process equipment. Design programs are available
for virtually every unit operation and every type of common process equipment.
Chemical Engineeting provides a feature, “Chemputer,” in each issue reporting
on computer hardware and software developments and periodically publishes a
comprehensive list of programs useful to chemical engineers. The “Software”
department of Chemical Engineering Progress likewise reports on software of
interest to chemical engineers.
The Computer Aids for Chemical Education (CACHE) CorporationS
makes available several programs intended mainly for educational use, but
provides them at modest cost to anyone. CACHE is a not-for-profit organization
whose purpose is to promote computer- and technology-based aids for chemical
engineering education.
The critical need for chemical and physical property data is apparent to
anyone who has worked on process-design projects. Property storage or predic-

tG. Ross, “Computer Programming Examples for Chemical Engineers,” Elsevier, Amsterdam, 1987;
D. J. Deutsch, ed., “Microcomputer Programs for Chemical Engineers,” Vol. 1, 1984 and Vol. 2,
1987, McGraw-Hill Book Co., New York; D. Wright, “Basic Programs for Chemical Engineers,”
Van Nostrand Reinhold Co., Inc., New York, 1986.
$CACHE Corporation, P.O. Box 7939, Austin, TX 78713-7939.