Question

For economical operation in gas absorption, the operating line approximately:

• A. lies parallel above the equilibrium line
• B. lies parallel to the equilibrium line
• C. coincides with the equilibrium curve
• D. is tangential to the equilibrium curve

Hint:

For efficient gas absorption, the operating line should be parallel to the equilibrium line to ensure gradual and effective absorption.

Answer 1

The Correct Option is B

Step 1: Understanding the gas absorption process.
In gas absorption, the operating line is drawn on a plot of concentration of gas versus liquid. For efficient operation, the operating line should lie close to the equilibrium line, but typically, for optimal performance, it is **parallel to the equilibrium line**. This ensures a gradual and economical absorption process, avoiding excessive contact time between the gas and liquid phases.

Step 2: Explanation of other options.
- (A) The operating line should not lie above the equilibrium line in this context, as this would indicate inefficient operation. - (C) The operating line does not coincide with the equilibrium curve because this would imply no absorption is occurring. - (D) Tangency to the equilibrium curve would imply a very specific, possibly inefficient operating condition, not ideal for gas absorption.

Final Answer: \[ \boxed{\text{B) lies parallel to the equilibrium line}} \]