Removal of Triethylamine Vapor From Waste Gases by Biotrickling Filter

Sampling of triethylamine in the cold-box unit in an auto-manufacturing company in Iran has indicated the average concentration of 430 mg/m3 in the emission duct. In this study a biotrickling filter was used for treatment of triethylamine in air stream. Triethylamine removal efficiency (K/L) pattern was evaluated by changing volumetric loading (L), superficial gas velocity (Uo), empty bed gas retention time (EBRT) and recirculation liquid flow rate (VL), while operating at constant temperature of 25 ± 1ºC. For finding the effect of EBRT on the triethylamine removal efficiency, tests were performed at EBRT of 156s, 52s and 31 s and a constant liquid recirculation velocity of 3.466 m3/m2/h. Results showded that for a test period of 65 days, triethylamine removal efficiencies of more than 98% were obtained for EBRT of 156 s and loading rates of less than 48 g/m³/h. With an EBRT of 52s removal efficiencies of > 90% were obtained for loadings of 57 g/m³/h and maximum removal capacity was 53.4 g/m³/h at volumetric loading of 64 g/m³/h. Also with an EBRT of 31 s the maximum removal capacity was 53.6 g/m³/h at volumetric loading of 68 g/m³/h. Thus in the range of implemented EBRTs the proper absorption of triethylamine from gas to liquid phase took place and the elimination efficiency was shown to be dependent on microorganisms activity rate. The effect of liquid flow rate on the triethylamine removal efficiency was investigated by changing VL in the range of 3.46 to 10.40 m³/m²/h at EBRT=31 s and influent triethylamine concentration of 600 mg/m3. Results showed that the triethylamine removal efficiency was nearly independent of the liquid recirculation rate.