The document outlines a process flow for producing diethyl ether (DEE) using a packed bed reactor with alumina catalyst, detailing the chemical reactions, temperatures, pressures, and selectivity involved. It describes the separation train designed to achieve 99.5% purity of DEE through flash vessels and heat exchangers, subsequently recycling ethanol for efficient use. Wastewater treatment is also mentioned for by-products before discharge.

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Table 2.1: name and number of equipment in the flowsheet
Number 1 2 3 4 5
Name Reactor Heat
exchanger
Distillation
column
Distillation
column
Flash
vessel
6 7 9 10 11 12
Heat
exchanger
Flash
vessel
Heat
exchanger
Heat
exchanger
Pump Heat
exchanger
for one month when ethanol is not available. In addition, it provides flexibility in
scheduling feed replenishment and helps ensure consistent production.
2.7.2 Reactor Section
It is packed bed reactor. The reactor contains packed bed of alumina catalyst. The main
reaction is,
2C2H5OH (C2H5)2O H2O (2.14)
Ethanol DEE
Reaction is exothermic, reversible, and limited by equilibrium. The reaction occurs at
medium temperatures (400-600 K) and high pressures (1000-1500 kPa). The alumina
catalyst minimizes (but does not eliminate) side reactions at higher temperature. For
simplicity, assume that the only side reaction that occurs in Reactor is the dehydration
of DEE to form ethylene:
(C2H5)2O → H2O + 2C2H4 (2.15)
DEE Ethylene
The primary reaction is limited by equilibrium. The selectivity of the ethylene side
reaction is a function of reactor temperature and pressure.
In this process isothermal reactor is used. Inlet temperature is 200o
C and pressure is
1500KPa. It is gas phase reaction. The conversion of ethanol is 52.5% and selectivity
of diethyl ether (DEE) is 93%. [7]
The reactors is filled to capacity with γ-alumina catalyst in the form of 1cm diameter
spherical pellets. After regular time interval catalyst is necessary to discard and replace all

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of the catalyst. Regeneration is not feasible because the loss of catalytic activity is due
directly to irreversible damage caused by constant exposure to the high temperature and
pressure conditions in the reactor.
Before reactant enter in the reactor from feed storage tank it is mixed with recycle stream
and after that it is heated up to 250o
C.
Upon leaving the reactor, the products enter HX-6 which lowers their temperature to
166o
C. After product stream enters heat exchanger reduce the temperature up to 37o
C. It
is desirable to remove as much heat as possible from this stream since the separation train
requires low temperatures.
2.7.3 Separation Train
After the reactor effluent stream passes through heat exchanger, it enters the separation
phase of the process. The separations section is designed to bring the Diethyl ether(DEE)
product to a 99.5% purity using as little equipment and as few utilities as possible. Effluent
stream enters in flash vessel (5), at 37o
C high pressure knock out drum. The overhead
stream from flash vessel, contains most of the ethylene that is formed in an undesirable
side reaction along with small amounts of DEE and ethanol. This stream is sent to another
process as fuel gas.
Bottom of the flash vessel is heated to 80°C in HX-12 using low-pressure steam. The exit
stream from HX-6, enters the DEE purification column (3) where the DEE is separated
from the water and ethanol. It should be noted that since the feed to column contains small
amounts of ethylene a partial condenser is used. The overhead product from this column
is then cooled in HX-9 and is then fed to the low pressure flash vessel (7). The overhead
stream from flash vessel is vented to flare and the liquid product is the DEE 99.5+%
product stream that is sent to storage where a peroxide inhibitor is added.
The bottom product from column (3) is sent to a second column (4), where the ethanol is
purified as the top product to a 85 mol% pure aqueous mixture. This mixture is pumped
back to the feed pressure using Pump (11) and returned to the front end of the process. The
bottom product stream, Stream 12, is water with trace amounts of organic material that
is cooled to 37°C in HX and then sent to wastewater treatment prior to discharge to the
environment.