Separation of CO2/CH4 using carbon molecular sieve (CMS) at low and high pressure

Abstract

Separation of CO2 from CH4-rich streams is an important separation for upgrading biogas and natural gas. The main difference between these two sources of methane is the pressure at which they are available. In order to design an adsorption process without extrapolating data, it is necessary to measure the behaviour of the adsorbent in the current conditions.In this work, adsorption properties of CH4 and CO2 on a commercial carbon molecular sieve (CMS) material are reported. Adsorption equilibrium of pure gases at 298 and 343K were measured until 70bar for CH4 and 30bar for CO2. In order to determine the performance of the adsorbent using a real mixture, binary breakthrough curves (10% CO2–90% CH4) were measured at 314K at pressures from 5 to 70bar. A mathematical model was used to interpret the data obtained.