含油污泥催化热解及残渣资源化利用实验研究

Experimental study on catalytic pyrolysis of oily sludge and recycling of the residue

为了达到含油污泥无害化和资源化处理的目的,使用真空管式热解炉对某炼油厂的含油污泥开展了催化热解实验。以油相回收率为评价指标,优选出了最佳的催化热解工艺参数,并将热解残渣经过活化处理后应用于含油废水的吸附处理中。催化热解实验结果表明:当催化剂活性白土的加量为1.5%(质量分数)、热解温度为440℃、热解时间为3 h、升温速率为10℃/min时,油相的回收率可以达到87.8%,达到了高效回收油相资源的目的。热解残渣使用KOH和NaOH活化处理后,其比表面积和孔体积明显高于商用活性炭,并且其重金属浸出含量远小于标准控制值。活化后的热解残渣吸附性能评价结果表明:当热解残渣加量为3%(质量分数)时,含油废水中的石油类物质含量降低率可以达到90%以上,COD值降低率可以达到95%以上,吸附效率明显高于商用活性炭,经过热解残渣吸附处理后的废水中石油类物质含量和COD值均可满足GB 8978-1996《污水综合排放标准》中的一级排放标准要求,实现了热解残渣资源化利用的目标。

In order to achieve the goal of harmless treatment and recycling of oily sludge,a vacuum tubular pyrolysis furnace was employed in this study to conduct the catalytic pyrolysis experiment on the oily sludge from a refinery.Taking the oil phase recovery rate as the evaluation index,the process parameters were optimized while the pyrolysis residue was activated and subsequently applied to the adsorption treatment on the oily wastewate.The results showed that when the amount of activated clay was 1.5%(mass fraction),the pyrolysis temperature was 440℃,the pyrolysis time was 3 h,and the heating rate was 10℃/min,and the recovery rate of oil phase could reach about 87.8%,a value could be regarded as efficient recovery.Further,the specific surface area and pore volume of the pyrolysis residue activated by KOH and NaOH were identified to be significantly higher than those of commercial activated carbon,and the leaching content of heavy metals is far less than the limited values in the relevant standard.The evaluation on the adsorption performance of activated pyrolysis residues showed that when the dosage was 3%(mass fraction),the petroleum substance content and COD in oily wastewater could be reduced by more than 90%and 95%,respectively.The adsorption efficiency could be considered to be significantly higher than that of commercial activated carbon.The petroleum substance content and COD value in the wastewater after adsorped by the activated pyrolysis residue could satisfy the Class 1 requirements of GB 8978-1996 Integrated Wastewater Discharge Standard.In this study,the recycling of pyrolysis residue has been realized.