Hollow fiber membrane contactors (HFMCs) provide a large specific surface area. Thus, their significantly reduced volume provides an advantage compared to the conventional gas-liquid contactor. In this study, the selective removal efficiency of flue gas, in which sulfur oxide (SO2) and carbon dioxide (CO2) coexist, was measured using a polypropylene (PP) HFMC with such advantages. To increase the selective removal efficiency of SO2, experiments were conducted using various alkaline absorbents. As a result, with 0.05 M ammonia solution, the removal efficiency of 95% or more was exhibited with continuous operation for 100 h or more. We confirmed that the absorbent saturated by the once-through mode was aqueous ammonium sulfate ((NH₄)₂SO₄) solution and could be used as a fertilizer without additional processing.
Keywords: ammonium sulfate ((NH₄)₂SO₄); desulfurization; hollow fiber membrane contactor (HFMC); once-through mode; polypropylene (PP); sulfur oxide (SO2).