Evaluation of Biogas Production Rate by using Various Electrodes Materials in a Combined Anaerobic Digester and Microbial Electrochemical Technology (MET)

MET (Microbial Electrochemical Technology), such as MFC (Microbial Fuel Cell) and MEC (Microbial Electrolysis Cell), is a promising technology for producing sustainable biogas from an anaerobic digester (AD). At current stage, however, the most likely limiting factors, large internal resistances, should be overcome for successful scale up of this technology. Various researchers reported that application of electrode materials containing high current density, increase of ion strength and conductivity, configuration of electrode are good methods for minimizing internal resistances. Recently, stainless steel is receiving great attention because of not only high performance and durability but also low cost. Therefore, in this study, we evaluate electrochemical characteristics and biogas production rate using various electrode materials and configuration (graphite carbon coated with catalysts (GC-CM) or not (GC), stainless steel mesh (SUS-M) and plate (SUS-P)). As the results, current densities of GC-CM, GC, SUS-P, SUS-M were 2.03, 1.36, 1.04, 1.13 A/m2, respectively. Methane yields of GC-CM, GC, SUS-P, SUS-M were 0.27, 0.14, 0.19, 0.21 L-CH4/g-CODrem., respectively. Stainless steel shows high current density and methane yield, which are similar as graphite carbon coated with catalysts. Key words: MET (Microbial Electrochemical Technology), Electrode Material, Stainless Steel, Graphite Carbon, Biogas Production