THE STUDY OF HEAVY METAL CONTROL BY A FLUIDIZED BED REACTOR DURING INCINERATION

Bo-Chin Chiang*, Ming-Yen Wey, Wen-Yi Yang (Department of Environmental Engineering, National Chung Hsing University, Taichung, Taiwan, 40227, Republic of China)

The pollutants released from waste incineration flue gas included particulate, heavy metal vapors, acid fume, and volatile organic compounds. The formations of these pollutants are affected by the operating conditions, feed waste compositions, and adoptive air pollution control devices. Several techniques, such as scrubbers, bag houses, and electrostatic precipitators, can effectively remove the acid fume, particulate, and heavy metal compounds by dry, semidry, wet, filtration, and capture methods. On the other hand, condensation, incineration, catalysis oxidation, absorption, and adsorption techniques are utilized to control elemental organic pollutants.

Previous studies have indicated that an effective control technique, for heavy metal emissions from incinerators, is to use solid sorbents to capture metals by physical deposition and chemical adsorption. Most of them are performed in fixed bed reactors or injecting solid sorbents into the flue during incineration and the adsorption process in fluidized bed reactors are rarely studied. The fluidized bed has the advantage of bed temperature uniformity, high contact area, continue operating, high mass transfer efficiency and so on. Moreover, the fluidized bed adsorption reactor has the effect of filtration, so it can be regarded as an air pollution control device to remove the particulate. The current experiment is performed to relate the fluidization velocity, adsorption temperature, the ratio of different sorbents and fixed bed height of fluidized bed to the removal of heavy metal and heavy metal aerosols. The particle size distribution of the fly ash prior to and after flowing through the fluidized adsorption reactor will also be studied.