In: Other
In the production of sunflower oil, sunflower solid
containing 13.5 wt% oil and 86.5 wt% solids
are ground and fed to the stirred tank, along with the recycled
stream of liquid ethanol,
C2H5OH. The ground sunflowers are suspended in liquid for certain
time to allow maximum
extraction of sunflower oil into the ethanol. The stirred tank
effluent passes to a filter.
The filter cake contains 75.0 wt% sunflower solids and the balance
sunflower oil and ethanol,
the latter two in the same ratio in which they emerge from the
stirred tank. The filter cake is
discarded and the liquid filtrate is fed to a heated evaporator in
which the ethanol is vaporized
and the oil remains as a liquid product. Subsequently, the ethanol
vapor is cooled and
condensed, and the liquid ethanol condensate is recycled to the
stirred tank.
By taking a feed ratio of 3 kg ethanol/kg sunflower, construct a
complete block diagram with
label. Calculate flowrate and compositions at each stream. State
clearly your assumptions
and basis of calculation.
An additional unit operation (heat exchanger) might be added to the
process. With brief
explanation, suggest the most suitable location to install the
unit. Write down your opinion
and conclusions on how the incorporation of this unit might or
might not improve the process
economics.
(23marks)