Currently, natural gas provides one 4th of the world’s energy
needs for homes, vehicles and industries (Cavenati et al., 2004).
Typically natural gas contains 80–95% methane; the rest is made
of C2+
hydrocarbons, nitrogen, and carbon-dioxide impurities.
High concentration of carbon dioxide in methane can lead to
pipeline and equipment corrosion and therefore, reducing it to
trace levels is necessary to achieve the pipeline quality methane
(no more than 2% CO2) (Cavenati et al., 2006). Typically the
separation of CO2 is accomplished by chemical absorption with
amines which is energy intensive and requires high reagent costs
(Rao and Rubin, 2002)