污泥的超临界水氧化动力学研究  

Study on Kinetics of Supercritical Water Oxidation of Municipal Sludge

作　　者：昝元峰[1] 王树众[1] 张钦明[1] 段百齐[1] 沈林华[1] 林宗虎[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,西安710049

出　　处：《西安交通大学学报》2005年第1期104-107,110,共5页Journal of Xi'an Jiaotong University

基　　金：国家重点基础研究发展规划资助项目 (2 0 0 3CB2 1 450 0 )

摘　　要：在间歇式反应器中研究了城市污泥的超临界水氧化反应,反应温度为400～450℃、压力为24～28MPa、反应时间为40～515s.结果表明:污泥的有机物去除率可达99 9%以上;在420℃、反应时间为155s时,污泥氧化后残余固体物的体积仅为脱水污泥的4%,反应后剩余收集液的COD小于10mg·L-1.以幂函数方程描述了氧化剂过量时污泥超临界水氧化的反应动力学规律,污泥和氧化剂的反应级数分别为1和0;速率常数与温度的关系符合Arrhenius公式,随反应时间增加、温度升高,有机物的去除率显著增加;速率常数随压力升高而增加,但速率常数的增幅随压力的升高而减小,反应活化体积不是常数.在24MPa时,反应活化能和频率因子分别为(39 11±2 216)kJ·mol-1和(45 2±17 2)s-1,模型计算值与实验值的误差在±8%以内.The experiment of supercritical water oxidation (SCWO) of municipal sludge was conducted in a batch reactor at 400-450°C, 24-28 MPa, and reaction time 40-515 s. The experimental results indicate that the chemical oxygen demand (COD) reduction can be over 99.9%. Moreover, the volume of residual solids is only 4 percent of the dehydrated sludge, and the residual COD of reaction liquid is less than 10 mg&middotL-1 at 155 s and 420°C. The global kinetics for municipal sludge COD disappearance was described with a power-law equation, which is first order in sludge COD and zero order in oxidant when having excess oxidant. The relation between the global rate constant and temperature can be satisfactorily explained by Arrhenius law. The COD reduction of municipal sludge obviously increases with reaction time and temperature and hardly changes with the excess oxidant ratio when it is over 3.25. The global rate constant increases with the increase of pressure, but its rising rate diminishes as the pressure further enhances and the activation volume is not a constant. At 24 MPa, the values of activation energy and frequency factor are (39.11 + 2.216) kJ&middotmol-1 and (45.2 + 17.2) s-1, respectively. The deviations between calculation and experimental values are within ±8%.

关 键 词：城市污泥 超临界水氧化 动力学 反应速率常数 

分 类 号：X703.1[环境科学与工程—环境工程]