AirScience - Model PSA - Gas Drying Pressure Swing Adsorption Process
This process is used at high pressure for the drying of gas from the discharge of carbon dioxide removal system, to very low dew point prior to the liquefaction of natural gas. The duty of the PSA in this application is to remove all humidity from a gas saturated with humidity as it exits the amine scrubbing system (CO2 removal system).
The dehumidification load is high and the required output is very stringent. PSA at high pressure is the only recommended process for this duty.
The saturated gas enters the first tower where all humidity will be remove in a single pass. The other towers are to recover the most pressure and methane in a sequence similar to the VPSA sequence, only at a much higher pressure.
Dew point of -70˚C are obtained with this process.