Biochemical Engineering

Question: The increased air flow rate in bubble column fermenter can cause excessive foaming and high retention of air bubbles in the column which
[A].

decreases the productivity of the fermenter

[B].

increases the productivity of the fermenter

[C].

modestly increases the productivity of the fermenter

[D].

does not affect on the productivity

Answer: Option A

Explanation:

No answer description available for this question.

Question: The bubble column fermenter is usually limited to
[A].

aerobic fermentations

[B].

anaerobic fermentations

[C].

Both (a) and (b)

[D].

facultative fermentation

Answer: Option A

Explanation:

No answer description available for this question.

Question: The contents in jet loop reactor are mixed through
[A].

compressed air

[B].

a mechanical agitator

[C].

external pumping

[D].

any of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: The high oxygen transfer efficiencies of airlift bioreactors is due to
[A].

the large aspect ratio of the reactor, which leads to a high gas hold-up

[B].

the large aspect ratio of the reactor, which leads to a high oxygen solubility at the base of the reactor

[C].

the draft tube, which reduces bubble coalescence in the reactor

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: The main function(s) of a draft tube in an air lift fermenter is/are to
[A].

increase the solubility of oxygen

[B].

distribute shear forces throughout the reactor and minimise bubble coalescence

[C].

concentrate shear forces around the sparger

[D].

concentrate shear forces near the disengagement zone

Answer: Option B

Explanation:

No answer description available for this question.

Question: The function(s) of the draft tube in an airlift bioreactor is
[A].

to reduce bubble coalescence

[B].

to improve circulation

[C].

to even out shear conditions throughout the reactor

[D].

all of the above

Answer: Option D

Explanation:

No answer description available for this question.

Question: The advantage of airlift bioreactors over stirred tank bioreactors of a similar size is
[A].

higher oxygen transfer rates

[B].

more uniform shear conditions

[C].

both (a) and (b)

[D].

less foaming

Answer: Option C

Explanation:

No answer description available for this question.

Question: In an airlift bioreactor, the air sparging region is called
[A].

downcomer

[B].

disengagement zone

[C].

air riser

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: To describe components of an airlift bioreactor which of the follow-ings are generally included?
[A].

Disengagement zone, air riser, downcomer

[B].

Flotsam, jetsam, downzone

[C].

Air comer, disentanglement zone, downsizer

[D].

All of the above

Answer: Option A

Explanation:

No answer description available for this question.

Question: Which of the following statements would be appropriate while comparing bubble column and air lift fermenter of the same size?
[A].

The average bubble size is smaller in an airlift bioreactor

[B].

Oxygen transfer rate is higher in an airlift bioreactor

[C].

The surface area for gas exchange is higher in an airlift bioreactor

[D].

All of the above

Answer: Option D

Explanation:

No answer description available for this question.