Study on the treatment of oily sludge in North China oilfield by smoldering.

The influence of oil content, water content, ventilation rate and medium particle size on smoldering of sludge in North China oilfield was studied by means of self-made smoldering equipment. Result showed that when the oil content is 6% - 18%,the water content is 0 -12%,and the ventilation rate is 0. 796 -6. 368 cmv's,the oily sludge can be ignited successfully and realize the self-sustaining combustion state,in which the degradation efficiency of petroleum hydrocarbons is as high as 99%. The degree of complete combustion of oily sludge can be improved effectively if the oil content decreases or the ventilation rate increases appropriately under the condition that the oily sludge can be smoldered. Finally,TG-DSC and elemental analysis results show that smoldering temperature is lower than the decomposition temperature of mineral salts,which can effectively avoid the generation of harmful gases such as SOx,NOx. [ABSTRACT FROM AUTHOR]