revision

Question 1

what is phase creation + example

Answer 1

creation of a second phase which is immiscible with the feed e.g. distillation

Question 2

what is phase addition?

Answer 2

for a homogeneous mixture, a second immiscible phase must be developed, MSA

Question 3

disadvantages of MSA?

Answer 3

additional separator needed, contamination, MSA needs making up, difficult design

Question 4

what is separation by barrier + example

Answer 4

use of a microporous or non-porous membrane e.g. osmosis

Question 5

what is separation by a solid agent + example

Answer 5

uses a solid mass-separating agent e.g silica gel

Question 6

what is separation by force field/gradient + example

Answer 6

makes use of the response of different molecules/ions to force fields e.g. gravity

Question 7

what things do we consider when choosing a separation method?

Answer 7

feed + product conditions, property differences, characteristics of operation, economics

Question 8

a light key product has…?

Answer 8

high relative volatility, low boiling point

Question 9

a high key product has…?

Answer 9

low relative volatility, high boiling point

Question 10

percentage recovery =

Answer 10

amount of i in product / amount of i in feed

Question 11

percentage purity =

Answer 11

amount of desired product / total amount of product

Question 12

split fraction =

Answer 12

amount of first product in product stream / amount of desired product in feed stream

Question 13

split ratio =

Answer 13

amount of product 1 / amount of product 2

Question 14

split ratio for 2 product streams =

Answer 14

SF / (1 - SF)

Question 15

separation factor (or power) =

Answer 15

(conc i in product 1 / conc i in product 2) / (conc of j in product 1 / conc of j in product 2)

Question 16

what value of separation factor can we expect?

Answer 16

SP > 1, close to one is a low degree of separation factor