Chemical Engineering - Mass Transfer - Discussion

The main points of advantages have been captured here,

It requires minimum structure.
The packed column causes a minimum pressure drop.
The liquid hold-up is relatively low in the packed column.
The packed column can easily handle highly corrosive, foaming fluid.

C is the correct answer.

Low-pressure drop. The packed tower has a higher voltage, so the pressure drop is lower than the plate tower. In the normal condition, the pressure drop of the plate tower is about 0.4 - 1.1 kPa per unit theoretical stage while the packed tower is about 0.01- 0.27 kPa. The low-pressure drop can not only save the operating cost but also save energy. It is very suitable for heat-sensitive material separation.

Low liquid hold-up quantity. Liquid hold-up quantity refers to the liquid quantity on the packing surface, internals and plates. The liquid hold-up quantity of the packed tower is less than 6% while the plate tower is higher to 8-12%. Though the higher liquid hold-up quantity can ensure the stable structure of materials and tower, it needs long operating hours, long operating periods and expensive operating costs, which is bad for the distillation process.

@Udit.

Explain how ∇P is low in packed tower.

I think C is the correct answer.

Because in packed tower entrainment is less, so liquid hold up is less & obviously lower pressure drop in the packed column than plate column.

I think the option A is correct.

The packed tower has a low-pressure drop but high contact time.

What is correct?

In packed tower low-pressure drop and high contact.

I think the right answer is B.

Isn't the packed tower should provide higher pressure drop?