Disclosed is a method and a device for capturing the SO2 present in gases by igneous electrolysis implemented on a group of at least two filtering modules traversed in parallel by the gas flow to be purified, and supplied with a powder material sorbent capable of adsorbing effluents in the gas flow by bringing the sorbent into contact with the gas flow, each filtering module having a unit for collecting the sorbent after it has been brought into contact with the gas flow, in the filtering module, and a unit for discharging the sorbent collected being contact with the gas flow to a unit for injecting same into at least one other of the filtering modules of the at least one series, except for the last filtering module of each series, and, on exiting the last filtering module or modules, the gas flow is sent to a desulfurization unit.