The Performance of Hydrated Lime Derived from Industrial Brine Sludge Waste in Spray Dry Scrubbing of SO₂

Abstract

Spray dry scrubbing is a popular method for removing sulfur dioxide (SO2) gas from industrial flue gases, with hydrated lime (Ca[OH]2) being a preferred sorbent due to its high reactivity. This study investigated the feasibility of using Industrial Brine Sludge Waste (IBSW) from the chloralkali industry as a source of Ca[OH]2. XRF analysis revealed that IBSW had a high content of CaO (89.05%), making it a suitable starting material for the production of a calcium-based sorbent. A laboratory-scale spray dry scrubber was used to test the performance of the prepared Ca[OH]2 sorbent. The desulfurization efficiency was analyzed by investigating how the SO2 capture in the spray dryer was influenced by the inlet flue gas temperature (120–180 °C), slurry pH (6–12), Ca:S ratio (1.0–2.5), and sorbent particle size (−45 µm to −90 µm). The highest SO2 capture rate of 88.54% was achieved under the following conditions: inlet flue gas temperature of 120 °C; Ca:S ratio of 2.5; particle size of −45 µm; and a slurry pH of 12. The results suggest that IBSW can be a viable starting material for producing Ca[OH]2 sorbents, which could then be utilized in the spray dry scrubbing process to remove SO2 from industrial flue gases.

Keywords

• industrial waste
• spray drying
• hydrated lime
• desulfurization