Method and apparatus for separating nitrogen from a mixed stream comprising nitrogen and methane

Methods and apparatus for separating nitrogen from a mixed stream (40) comprising nitrogen and methane employing a monolith sorption contactor (2) formed of a unitary construction of active carbon, said contactor (2) housing one or more separation flow channels (2a) intersecting the monolith sorption contactor (2), said one or more separation flow channels having at least one inlet (2b) to, and at least one outlet (2c) from, said contactor (2), said one or more separation flow channels (2a) defining one or more first internal surfaces (2d) of the monolith sorption contactor (2), said contactor (2) further comprising one or more first external surfaces (2e) provided with a barrier layer (2f), said first external surfaces (2e) being different from said first internal surfaces (2d). The mixed stream (40) is passed through at least one of the separation flow channels (2a), where methane is sorbed. The contactor (2) can be regenerated by contacting the contactor (2) with a heat exchange fluid (100) via the barrier layer (2f) at one or more of the external surfaces (2e).