Description
The nitrogen pressure swing adsorption
(PSA) process concentrates nitrogen
from air by utilising the faster rate of
adsorption of oxygen over nitrogen of a
unique carbon molecular sieve (CMS).
The Aalborg nitrogen PSA plants
use a two‑bed process, which has been
developed over a number of years.
As compressed and dehumidified air
passes over a bed of CMS, oxygen is
adsorbed initially at a faster rate than
nitrogen, causing the product gas leaving
the bed to be enriched nitrogen.
After a set period of time, the air flow
over the bed is stopped and the bed
is depressurised. As this happens, gas
adsorbed on the CMS is desorbed and is
vented away. When this regeneraration
of the CMS is complete, the bed can be
repressurized ready to go back on stream
to produce more nitrogen.
The CMS used is based on coconut as raw
material. This is superior in quality for this
application.
The plant consists of three main
components:
A fresh water cooled oil injected rotary screw compressor
A 407C filled refrigeration dryer
A pressure swing adsorption (PSA) unit with buffer tank
