527 Q9 Ch6 Air Separation

The operating temperature of an air distillation column (to separate O₂ from N₂) is maintained

• between the boiling points of N₂ and O₂

• higher than the boiling point of O₂

• lower than the boiling point of N₂

• lower than the boiling point of CO₂

Cryogenic distillation of air offers the highest O₂ yield compared to other separation technologies (like PSA and membranes), but PSA and membranes are competitive in small-scale applications.

• True

• False

CO₂ can be separated as a solid (dry ice) if the gas mixture containing CO₂ is cooled to a low enough temperature.

• True

• False

In cryogenic distillation for post-combustion CC, the flue gas must be first compressed and pretreated to remove any water.

• True

• False

Carbon molecular sieves (CMS) and zeolites sorbents separate air by

• capturing N₂ and allowing O₂ to pass through.

• capturing O₂ and allowing N₂ to pass through.

• capturing CO₂ and allowing air to pass through.

• (all these options are viable)

The mechanism of carbon molecular sieves (CMS) for air separation is based on

• kinetic diameter

• molecule polarity (dipole moment)

• molecule reactivity (quadrupole moment)

• (none of these options)

The mechanism of zeolite sorbent for air separation is based on

• kinetic diameter

• molecule polarity (dipole moment)

• molecule reactivity (quadrupole moment)

• (none of these options)

Metal-organic frameworks (MOFs) sorbents separate air by

• capturing N₂ and allowing O₂ to pass through.

• capturing O₂ and allowing N₂ to pass through.

• capturing CO₂ and allowing air to pass through.

• (all these options are viable)

The primary advantage of using polymeric membranes for air separation is that operation can be near ambient conditions.

• True

• False

If a polymeric membrane is used for separating air that contains N₂, O₂, CO₂, and H₂O, which gases will permeate through the membrane?

• O₂, CO₂, and H₂O

• N₂

• O₂ and H₂O

• O₂ and CO₂