527 Q3 Ch3 Absorption 1&2

In CC by absorption, the PRIMARY mechanism governing the capture of CO2 is

• mass transfer

• energy transfer

• chemical reaction of CO2 with the solvent

• dissociation of CO2 into CO + O

Absorption and stripping equipment use

• trayed columns only

• packed columns only

• spray towers only

• bubble columns only

• all of them

The rate of mass transfer in an absorption process depends on

(check all that applies; no partial credit)

• the length of mass-transfer zone

• the solubility of CO2 in a given solvent

• the diffusivity of CO2 through the solvent

• the chemical reactivity between CO2 and the reactive component of the solvent

Increasing the column height / number of stages increases the fraction of CO2 captured, while the diameter of the column is used to control the flows and pressure drop based upon the fluid properties.

• True.

• False.

• The fraction of CO2 captured is NOT a function of the column height and diameter.

Put these steps of CO2 separation by absorption into the correct order:

(A) CO2 transfer into the liquid phase

(B) CO2 transfer through the gas phase

(C) CO2 transfer across the gas-liquid boundary

(D) Chemical reaction of CO2 with the binding agent in the liquid phase

(E) Diffusion of CO2 to a binding agent in the liquid phase

• B then C then A then E then D

• B then A then C then D then E

• E then D then C then B then A

• A then B then C then D then E

To increase the solubility of CO2, we should

• increase temperature and decrease pressure

• decrease temperature and increase pressure

• increase both temperature and pressure

• decrease both temperature and pressure

What is an ionic liquid?

Ionic liquids have greater CO2 solubility than aqueous solutions.

• True.

• False.