The current study investigated the performance of biological methanation of CO2 using green H2 in a mesophilic (37℃) trickle bed reactor (TBR) (0.051m3) at ambient pressure. For both phase A and phase B a synthetic gas feed (60/40 CH4/CO2) was used to simulate biogas. Nitrogen was used in phase A for better monitoring of the system. For phase A the average productivity of methane was 3.2 m_(CH_4)^3/(m_(trickle bed)^3*d) at methane content of 71.3% with 10.3% N2. For phase B no Nitrogen was used, and the average productivity of methane was 1.3 m_(CH_4)^3/(m_(trickle bed)^3*d) at methane content of 97.9% with less than 0.1% residual H2.