城市生活垃圾与煤矸石混烧特性及其HCl排放特性研究

利用热重分析仪对城市生活垃圾与煤矸石单独及混合燃烧特性进行了研究,并采用高温管式炉燃烧装置考察了PVC、NaCl及MSW与煤矸石混烧过程中HCl的排放规律。结果表明,在煤矸石中掺烧部分MSW可有效改善煤矸石的燃烧特性,尤其是脱挥发分和着火特性。综合考虑燃烧特性变化,建议MSW掺混比例为20%。PVC与NaCl掺混比较低时,煤矸石可抑制PVC燃烧过程中HCl的析出,会显著促进NaCl中HCl的析出;当掺混比增大时,上述作用逐渐减弱。MSW与煤矸石混烧时,会促进HCl的析出,增大烟气中HCl的浓度。当掺混比为10%时,HCl排放浓度达到56.22 mg/m~3,已超过中国国家标准,必须采取相应脱氯措施。

Co-combustion characteristics of municipal solid waste with coal gangue and its HCl emission

Co-firing of municipal RDF and coal gangue in existing coal gangue power station is a potential treatment way of municipal solid waste and coal gangue. The co-combustion characteristic of municipal solid waste (MSW) and coal gangue was investigated by thermogravimetric analyzer. The HCl emission in co-combustion of coal gangue with PVC, NaCl and MSW were also studied using a high-temperature tube furnace combustion system. The results show that the combustion characteristic of coal gangue can be improved obviously with blending of MSW, especially for devolatilization and ignition characteristics. In consideration of combustion characteristics, the MSW blending ratio of 20% is suggested. When the blending ratio of PVC or NaCl is low, the existence of coal gangue can inhibit the release of HCl in PVC while promote the release of HCl in NaCl. As the increase of blending ratio, the effect decreases gradually. In co-combustion of MSW and coal gangue, the release ratio and concentration of HCl is increased. When the MSW blending ratio is 10%, the HCl emission concentration is 56.22 mg/m³ which exceeds the national standard. Hence, the dechlorination measurement should be considered.