Q1: Even though bubble cap towers are very effective for humidification operation, they are not used commonly in industries, because of the

ANS:B - high pressure drop of the gas.

Even though bubble cap towers are very effective for humidification operations, they are not commonly used in industries due to the: high pressure drop of the gas. Bubble cap towers, while effective at achieving good contact between the gas and liquid phases for mass transfer, can result in significant pressure drops as the gas flows through the tower. This high-pressure drop can increase energy consumption and operational costs, making bubble cap towers less attractive compared to other alternatives, such as packed towers or spray towers, which may offer similar or better performance with lower pressure drops. The other options mentioned, such as high evaporation losses of water and difficulty in fabrication, are not typically the primary reasons for the limited use of bubble cap towers in industries. While these factors may also contribute to considerations in specific cases, the high pressure drop of the gas is generally the main factor that limits their widespread use.