209 4.23 Cheng Logan, 2007; Rozendal , 2007; 2006; Liu , 2005a) CO2 4H2 CH4 2H2O 4.23) 4.3 Liu 2005b 0.25 90 2.9 0.25 Cheng Logan 2007 Anion exchange membrane, AEM 0.2-0.8 0.6