My lab partner and I have finished the first lab period of the Unit Operation lab. For the first experiment, we get three lab periods to work on it. That’s plenty of time to make mistakes and correct them later on. This past Friday we looked at the pressure swing adsorption experiment.
The goal of this experiment is to analyze a pressure swing adsorption column by examining gas separation behaviors through the column. Pressure sing adsorption (PSA) is a two-step process where the first step involves sequential adsorption of one of the components in the gas mixture to a solid substrate. The second step is the desorption of that component from the solid substrate.
First of all, 15% Carbon Dioxide in Nitrogen is first fed to the column through a flow controller. The column is packed with activated Carbon as the adsorbent which will adsorb the Carbon Dioxide from the gas stream into the adsorbent. The initial concentrations of the exiting stream will have a 0% CO2 because CO2 is being adsorbed into the system. However, it will eventually reach a point where the column becomes saturated and the exiting concentration starts to grow. The time when the exiting concentration eventually reaches a point where it is the same as the inlet concentration is called the saturation time.
In the desorption process, a stream of pure Nitrogen is being fed into the system, which will allow CO2 to be stripped off from the packing. A reduction of the CO2 concentration will be observed because more CO2 is stripped off first, and eventually all of the CO2 is stripped off, giving 0% CO2 concentration at the exiting stream.
Below is a process flow diagram as described above.