Pyrolysis and combustion characteristics of dried sewage sludge in a fixed bed reactor

건조 하수 슬러지의 열분해 및 고정층 연소 특성 연구

The practical route for disposal of sewage sludge becomes energy recovery by combustion after its ocean dumping is banned in 2012 in Korea. Due to the high moisture content, however, sewage sludge is required to be dried before transport and combustion. In this study, pyrolysis and combustion characteristics of dried sewage sludge was investigated in a small-scale fixed bed reactor in order to provide fundamental data for energy recovery of the fuel. As the first step of combustion, the primary products of pyrolysis were analyzed in a fixed bed reactor for the condensable volatiles (tar), non-condensable gases, and char. For the combustion characteristics, another fixed bed reactor was constructed to monitor the weight and temperature of the fuel particles during ignition and combustion under different air flow rates. The test results were used to derive the ignition and burning rates.