a

constant or coefficient

A

constant

A

phase A

A

component A

A

membrane area, e. g., in a single-stage separation or in continuous concurrent or countercurrent flow, that is, in differential permeation

A _membrane

membrane area in a membrane reactor

A

membrane area for a single cell in the rectifying section of a multistage or cascade operation (all cells in the rectifying section with equal areas); also the area in the rectifying section for differential permeation

A

area of the rectifying section for differential permeation

membrane area for a single cell in the stripping section for a multistage or cascade operation (all cells in the stripping section with equal areas); most generally = A

area of the stripping section for differential permeation

A or A _i

absorption factor, A= L/VK

b

constant

B

constant

B

component B

B

phase B

B

bottoms or reject product, in moles per unit time

c

constant

c

compressibility of a liquid (= ?, and as distinguished from the compressibility factor z)

mean value for c

c or c _i

concentration

C

constant

d

constant

d

differential operator

D

overhead or permeate product, in moles per unit time

D _i

diffusion coefficient or diffusivity; D _i = P _i in units of (distance) ²/time

F

feed or feedstream designator, moles or molar flow rate; feed to single-stage membrane separator; feed-stream to multistage or cascade membrane unit; feed-stream to continuous membrane unit

F ?

feed or feedstream flux, that...