Dry flue gas desulfurization refers to the process where CaCO₃ injected into the furnace is calcined at high temperature to decompose into CaO, which reacts with SO₂ in the flue gas to form calcium sulfate; alternatively, electron beam irradiation or activated carbon adsorption is used to convert SO₂ into ammonium sulfate or sulfuric acid.

Process flow of dry flue gas desulfurization: Biogas → Dehydration → Desulfurization → Flame retardation → Power generation or boiler combustion

Features of dry desulfurization(1) Simple structure and easy to use;(2) No on-site personnel required during operation; material is replaced regularly, with one unit in use and one on standby, operating alternately;(3) Desulfurization efficiency is high with new materials, but decreases in the later stage;(4) Compared with wet desulfurization, regular material replacement is required;(5) Relatively high operating costs;(6) Suitable for treating small gas volumes with high desulfurization precision requirements.