Page 94 - Analysis, Synthesis and Design of Chemical Processes, Third Edition
P. 94
Important Points
From this margin analysis, it is clear that the amount of DEE produced should be optimized, because
making ethylene is far less profitable. In addition, the maximum amount of DEE that the market can
support is not currently being produced. Therefore, supplementing the feed with ethanol should be
considered.
Because the main feed stream contains both reactants and an impurity (water), separation or purification
of the feed prior to processing should be considered.
In order to minimize the production of by-products (ethylene), the selectivity of the DEE reaction should
be optimized.
Alternative 1
In this option, shown in Figure E2.6(b), we do not separate the mixed alcohol feed, but we supplement the
feed with ethanol. We use one reactor for both reactions. The disadvantages of this case are that the
separations are complicated and we cannot optimize the reactor for both DME and DEE production.
Figure E2.6(b) Structure of Process for Alternative 1 in Example 2.6
Alternative 2
In this option, shown in Figure E2.6(c), feed is supplemented with ethanol and is separated into separate
