1. Solvent recovery: distillation tank exhaust port is discharged after condensation recovery. 2. Filtration and centrifuge: When using closed centrifuge and filter discharge, the material is directly exposed to the air. 3. Drying: The dry exhaust gas is discharged into the buffer tank, and is directly exposed to the air when discharged. What waste gas will be produced in the production process of Guobang Pharmaceutical Factory? 1. Flammable gases such as methanol, ethanol, dimethylamine, chloromethane, isoamyl alcohol 2. Toluene, ammonia, hydrogen sulfide and other toxic and harmful gases.