Effects of calcium agent combined with polyethyleneimine-grafted magnetic biochar on CO2 mineralization and in situ biogas upgrading

The effects of different calcium agents including CaCl2 and CaO addition were analyzed in an acidogenic off-gas assisted continuous two-stage AD system. Moreover, the magnetic biochar material grafted with polyethyleneimine (PMB) was co-supplemented with CaO (0.022 mol/L Ca2+) in methanogenic reactor, and excessive CaO (0.262 mol/L Ca2+) was added to improve CO2 mineralization.