Which of the following characteristics represents an undesirable property for a tower packing material ?
Show answer Hide answer
Answer: D. Large weight of liquid retained
Explanation
A large weight of retained liquid means high liquid hold-up inside the packed column matrix. Excessive liquid hold-up increases overall column weight and restricts the free gas flow cross-section. This restriction leads to premature flooding, high pressure drops, and severely reduced separation efficiency. Tower packings provide large interfacial areas to promote mass transfer between descending liquid and ascending gas. Ideal packing materials combine high void fractions with low bulk densities and excellent wettability. Pressure drop across a packed bed is a critical design parameter governing blower and compressor power needs.
Absorption and distillation columns in chemical plants require carefully selected structured or random packings. High pressure drops result in excessive operational energy costs and can destabilize column hydrodynamics. Engineers evaluate packing performance using generalized pressure drop correlation charts. Large surface area per unit volume is a highly desirable property to maximize mass transfer rates. Large free cross-section is desirable because it allows high gas throughput without causing flooding. Low weight per unit volume is desirable to minimize structural support requirements for the tower shell.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. Which of the listed apparatuses is not utilized in liquid-liquid extraction processes ?
Show answer Hide answer
Answer: A. Pachuka tank
A Pachuka tank utilizes pneumatic air injection for solid-liquid suspension and leaching rather than countercurrent extraction. It is fundamentally designed for hydrometallurgical ore dissolution rather than handling two...
Q2. Which transport property shares the identical dimension as mass diffusivity ?
Show answer Hide answer
Answer: D. Both B. and C.
Kinematic viscosity represents momentum diffusivity, while thermal diffusivity characterizes heat transport through a medium. Dimensional analysis confirms that kinematic viscosity and thermal diffusivity both share the...
Q3. When separating heat-sensitive products from high-boiling mixtures, the appropriate distillation technique to employ is _______________ distillation?
Show answer Hide answer
Answer: B. Steam
Steam distillation introduces direct steam into the mixture, lowering the total system vapor pressure significantly. This reduction in operating pressure allows high-boiling compounds to vaporize at much lower, safe temp...
Q4. Which of the following is an undesirable attribute for a gas absorption solvent ?
Show answer Hide answer
Answer: D. None of these
The correct answer indicates that none of the listed properties are undesirable because they are all required. An ideal gas absorption solvent must possess low vapour pressure to prevent significant vaporization into the...
Q5. Which chemical substance serves as a suitable absorbent for scrubbing H2S from natural gas streams ?
Show answer Hide answer
Answer: B. Monoethanolamine (MEA)
Monoethanolamine is an alkaline chemical solvent that reacts reversibly with acidic gases like hydrogen sulfide. This chemical absorption mechanism removes H2S efficiently from sour natural gas streams at ambient tempera...
Q6. Which of the following properties is undesirable for a solvent used in gas absorption ?
Show answer Hide answer
Answer: D. None of these
The correct answer is that none of the options are undesirable since every listed attribute is actually required for performance. Low vapor pressure ensures that the solvent remains in the liquid phase without evaporatin...