Separation Processes Concept Flashcards
A unit operation in which a soluble component is removed from
an inert solid by a solvent which preferentially dissolves the
soluble matter is known as
leaching
The unit operation by which soluble components of a liquid
mixture are dissolved in a liquid immiscible with the insoluble
component is
solvent extraction
Tea percolation employs
leaching
Neem oil is a traditional plant product which possesses
spermicidal properties. A group of students working on their
investigatory project wanted to test how effective the said oil was
as contraceptive by sing it as a component for contraceptives.
The students were able to gather 5 kg of Neem Tree Seeds that
contains 30% of soluble oil and 70% inert solids and they decided
to use 5 kg of pure hexane to extract the oil. What percentage of
oil will they be able to recover given that the ratio of the liquid to
solid components in the underflow is 0.5? Assume ideal
leaching.
73 %
Tung meal containing 55% oil is to be extracted at a rate of 4000
kg/hr using n-hexane containing 5% wt oil as solvent. A counter
current multiple stage extraction system is to be used. The meal
retains 2 kg solvent per kg of oil free meal while the residual
charge contains 0.11 kg oil per kg oil free meal while the product
is composed of 15 weight percent of oil. The theoretical number
of stages is
4
Which of the following is the most commonly used leaching
solvent in vegetable oil industry?
hexane
Leaching of sugar from sugar beets is done using
hot water
In a counter-current extractor, as the axial mixing increases, the
extraction efficiency
decreases
Bollman extractor
is used for extraction of oil from oilseed.
Radioactive nuclear waste is treated in
pulsed column extractor
Acetic acid will be most economically separated from a dilute
solution of acetic acid in water by
solvent extraction
Liquid-liquid extraction is based on the differences in
solubility
Which method is more efficient, a single large washing or
repeated small washing?
repeated small washing
A solution of solute (A) in diluent (B) is mixed with solvent (S).
The component (B) is slightly soluble in (S). The resulting
extract will be
rich in S, poor in B, rich in A
By extraction with amyl acetate, Penicillin F is recovered from an
aqueous fermentation broth using 6 volumes of solvent per 100
volumes of the aqueous phase. At pH = 3.2, the distribution
coefficient KD is 80.
What fraction of the penicillin would be recovered in a single ideal
stage?
83%
Benzoic acid is 9 times more soluble in chloroform than in water.
The percent benzoic acid that will remain from a water solution of
benzoic acid if
Equal quantity of chloroform and water is used is
10%
The solvent used in liquid extraction should not have high latent
heat of vaporization, because
its recovery cost by distillation may be prohibitively high.
Solvent extraction is the terminology applied to the liquid-liquid
extraction, which is preferred for the separation of the
components of liquids, when
extracting solvent is cheaply & abundantly available.
In a counter-current liquid extractor
only one of the liquids may be pumped at any desired rate.
A coalescer in a mixer-settler liquid-liquid extraction column
a. comprises of thin bed of substances of extended surface
having high porosity.
b. helps in increasing the bubble size entering the settler.
c. helps in increasing the settling rate of the bubbles.
Antibiotics are best handled in a
Podbielniak extractor
Which of the following solutions will follow Raoult’s law most
closely?
A solution of benzene, toluene and oxylene
The percentage change in the boiling point of a 20 mole benzene
– toluene solution when the pressure is increased from 1 atm to
2 atm is
25.5 % increase
A 50 % by weight benzene – toluene mixture is fed to a column
at 180 0F and 1 atm. The condition of the feed is called
sub cooled liquid