1. Dry Scrubbing Systems Wednesday, November 25 th Puu-0.4400 – Environmental Engineering 1 Department of Forest Products Technology Minh Khoi Le

2. Dry Injection (Apple, 1982) ○ Alkaline: Hydrated lime or soda ash powder ○ 50% SO2 and 90% HCl removal ○ Low temperature increase efficiency ○ Gas temperature >150°C to prevent water droplet ○ Stoichiometric ratio: 2 to 4

3. Spray Dryer Systems (Huang, 1988) ○ Slaked lime Ca(OH)2 ○ Higher SO2 and HCl removal ○ Low temperature increase efficiency

4. Operating & Design parameters (Huang, 1988) ○ Flue gas flow rate and composition ○ Temperature inlet and outlet of chamber ○ Alkaline stoichiometric ratio ○ Alkaline properties ○ Required removal efficiency

5. Maintenance Problems ○ Plugging in the solid or slurry transport system ○ Plugging in the atomizer and valves ○ Lime slaking system, quality of lime and water ○ Plugging in standby priod, lack of slurry movement => Require flush, regular maintenance, high quality alkaline substances