Modeling and Parametric Study for CO2/CH4 Separation using Membrane Processes

The upgrading of low quality crude natural gas (NG)
is attracting interest due to high demand of pipeline-grade gas in
recent years. Membrane processes are commercially proven
technology for the removal of impurities like carbon dioxide from
NG. In this work, cross flow
mathematical model has been
suggested to be incorporated
with ASPEN HYSYS as a user
defined unit operation in order to
design the membrane system for
CO
2
/CH
4
separation. The effect of
operating conditions (such as
feed composition and pressure) and membrane selectivity on the
design parameters (methane rec
overy and total membrane area
required for the separation) has b
een studied for different design
configurations. These configurations
include single stage (with and
without recycle) and double stag
e membrane systems (with and
without permeate or retentate recy
cle). It is shown that methane
recovery can be improved by recyc
ling permeate or retentate stream
as well as by using double stage
membrane systems. The ASPEN
HYSYS user defined unit operation proposed in the study has
potential to be applied for comp
lex membrane system design and
optimization
.