During catalyst removal from a reactor, which purge gas is used to prevent oxidation?

During catalyst removal from a reactor, which purge gas is used to prevent oxidation?

• A. Argon
• B. Nitrogen
• C. Oxygen
• D. Helium

Answer: (B)

Preventing oxidation by displacing air with an inert gas is the goal here. Nitrogen is used because it is chemically nonreactive with most catalysts and reactor materials under typical purge conditions, and it’s inexpensive and readily available. Introducing nitrogen into the reactor pushes out oxygen-containing air, so the catalyst isn’t exposed to oxygen during removal, which helps maintain catalyst activity. Argon and helium are also inert, but they are usually more expensive, so they aren’t the default choice for a routine purge. Oxygen would cause oxidation, so it’s not suitable.

Preventing oxidation by displacing air with an inert gas is the goal here. Nitrogen is used because it is chemically nonreactive with most catalysts and reactor materials under typical purge conditions, and it’s inexpensive and readily available. Introducing nitrogen into the reactor pushes out oxygen-containing air, so the catalyst isn’t exposed to oxygen during removal, which helps maintain catalyst activity.

Argon and helium are also inert, but they are usually more expensive, so they aren’t the default choice for a routine purge. Oxygen would cause oxidation, so it’s not suitable.