Page 103 - Analysis, Synthesis and Design of Chemical Processes, Third Edition

(3)

13.

(4)

The conversion of ethanol is typically 60%. The yields for each reaction are approximately:

(1) acetaldehyde 92%

(2) ethyl acetate 4%

(3) butanol 2%

(4) acetic acid 2%

a. For this process, generate a process concept diagram showing all the input and output chemicals.

b. Develop two alternative preliminary process flow diagrams for this process.

Consider the following process in which liquid feed material A (normal BP of 110°C) is reacted with
gaseous feed material G to produce main product C and by-products R and S via the following
reactions:

A + G → C + S

G + C → R

Both feeds enter the process at ambient temperature and pressure. Both reactions occur in the gas
phase at moderate temperature and pressure (250°C and 10 bar). The normal boiling points of G, S,
and C are less than –120°C. By-product R has a normal boiling point of 75°C and is highly soluble in

14. water. Product C is very soluble in water but G and S are insoluble. The single-pass conversion
through the reactor is low for feed A, and the ratio of G to A in the feed to the reactor should be
maintained in excess of 4 to minimize the chance of other unwanted side reactions. Using this

information, and assuming that both A and G are expensive, do the following.

a. Draw a preliminary process flow diagram identifying the main unit operations (reactors,
compressors, pumps, heat exchangers, and separators), and identify the recycle structure of the

process.