含油污泥微波热解工艺条件优化现场实验研究

Field test of microwave pyrolysis of oily sludge and the process optimization

采用自主设计的30kW大功率微波设备开展了含油污泥微波热解的现场实验,考察了吸波剂种类和添加量、热解终温、微波辐照时间、污泥处理量等对微波热解处理效果的影响。结果表明,污泥热解残渣可以作为吸波剂提高含油污泥的微波热解处理效果,综合考虑热解效果和成本,其较佳的添加量为5%(质量分数),此时污泥的除油率可达99.84%;随着热解终温的升高,污泥的除油率逐渐升高,当热解终温达到500℃时,处理后污泥的含油率降为0.200%(质量分数,下同),满足《农用污泥中污染物控制标准》(GB 4284—84)的限值标准(石油类限值为0.3%(质量分数));微波辐照时间对含油污泥的热解效果影响较显著,当微波辐照时间达到180min时,处理后污泥含油率仅为0.230%;含油污泥处理量低于20kg/次时,单位质量含油污泥完成热解消耗的电量随着处理量的增加而减少,而超过20kg/次时,耗电量随着处理量的增加而增加,因此本实验所用设备较经济的含油污泥处理量为20kg/次。

The field test of microwave pyrolysis of oily sludge was performed in the self-made microwave equipment （30 kW）. The effect of microwave absorbing material, final pyrolysis temperature, microwave radiation time and sludge treatment amount on treatment efficiency was investigated. Results showed that sludge pyrolysis residue could be used as microwave absorbing material and improve the pyrolysis treatment efficiency of oily sludge. Compre- hensively considered the pyrolysis efficiency and treatment cost, the proper addition amount of sludge pyrolysis residue was 5 % （mass ratio）. Under this condition, the oil removal rate could reach to 99.84 %. The oil removal rate of sludge increased with increasing the final pyrolysis temperature, when the final prtolysis was 500℃, the oil content of treated sludge decreased to 0. 200%, which could meet the limit value of pollutant control standard for agriculture sludge （GB 4284-84）. Microwave radiation time had significant effect on pyrolysis efficiency of oily sludge, after 180 min of radiation, the oil content of sludge could decrease to 0. 230N. Oily sludge treatment amount could influence the energy consumption of microwave equipment, and the economical treatment capacity of the self-made equipment was 20 kg per time.