화력발전소의 Bottom Ash를 이용한 다공성 경량 기능성 발포체 개발 및 특성 분석

Abstract

Porous functional ceramics has been developed and studied as a new application field of functional ceramics. The functionalized porous ceramics are less dense than ordinary ceramics. Therefore, porous functional ceramics can be applied to various fields such as filter, catalyst, carrier, various sensors, electrochemical, biomedical, electronic materials and sound absorbing materials. Sound absorbing materials are used in various forms such as asbestos, rock wool, glass wool, polyurethane, and polyester. The most widely used porous sound absorbing material is a polyurethane foam. Sound absorption performance of polyurethane foam is excellent, but polyurethane foam has a problem of double construction with a sound insulating sheet. Also polyurethane foam has the disadvantage of being weak to fire. Therefore, polyurethane foam absorption materials are unstable element to be used as interior and exterior materials of a building. We used Bottom ash from thermal power plants as the main material of the porous foam. Fly ash, one of the coal ash generated from thermal power plants, is collected by dry recovery from an electrostatic precipitator and recycled as a main raw material for cement. However, Bottom Ash is collected in wet recovery by seawater or freshwater and contains a large amount of salt, moisture and unburned carbon, so recycling is difficult. Currently, the amount of Bottom Ash produced by thermal power plants is increasing, but most of them are reclaimed without being recycled. Therefore, a most efficient way needed to recycle Bottom Ash. In this research, we synthesized Bottom Ash based porous foam for functional materials. As the binder, potassium silicate solution and environmentally friendly poly-urethane were used. The compression strength of potassium silicate solution based porous foam was 3.06 MPa. The far-infrared emissivity and emission power were confirmed 0.932 and W/(m2·μm), respectively. The deodorization rate of NH3, (CH3)3N, H2S, CH3SH, CH3CHO and C6H6CH3 were 85.7, 87.8, 99.8, 98.0, 67.3, and 89.8% respectively. The porous foam was satisfied the standard of the emission of environmentally hazardous substances when compared with standard values. The noise reduction coefficient were over 70% at 500 ~ 1000 Hz, and the highest rate at 630 Hz was 77%. The compression strength of environmentally friendly poly-urethane based porous foam was 0.79 MPa, and the far-infrared emissivity and emission power were confirmed 0.888 and W/(m2·μm), respectively. The deodorization rate of NH3, (CH3)3N, H2S, CH3SH, CH3CHO and C6H6CH3 were 69.4, 25.5, 26.5, 20.4, 14.3, and 12.2% respectively. The porous foam was satisfied the standard of the emission of environmentally hazardous substances when compared with standard values. The noise reduction coefficient were over 50% at 500 ~ 1000 Hz, and the highest rate at 800 Hz was 71%. In conclusion, we confirmed that the porous foams using Bottom Ash have various functionalities and it could be applied in various fields.