Gas Absorber

The experiment uses a randomly packed water counter-flow gas absorption column. The column is packed with 34 cm of 13 mm berl saddles with 465 m²/m³ surface (effective) area. The pressure entering the system is about 1.42 bar with a temperature of about 26 °C, and valves at the entrance and exit of the column allow gas to escape. An "Oxy Baby" Infra-red spectrometer, directly connected to the unit at various locations, measures gas composition, and tanks of pure gas are used for calibration.

1. Operating the Gas Absorber

1. Turn on the master switch and close the adjusting valve used to control the amount of water in the column
2. Open the air flow valve completely and the adjusting valve for column pressure.
3. Set the air flow rate to the desired level (use a minimum of 20 L/min and increase as needed), and set the column pressure to ~ 1.4 bar and 25°C using the adjusting valve for pressure.
4. Start the carbon dioxide flow rate at ~ 4 L/min.
5. Set the water flow at ~ 75 L/h, and adjust the water level to maintain a constant height. Tweak if necessary while running to ensure constant height.
6. Sample the CO₂ partial pressure at the base, center and head of the column using the pressure taps and the infra-red spectrometer.
7. Perform eight different runs, using two different gas flow rates, liquid flow rates, and CO₂ concentrations. This will enable determination of the most important variables.
8. Allow the system to achieve steady-state when any flow rate is altered. This typically takes 30 - 45 min.