Pyrolysis Technology Of Oily Sludge

Oily sludge is one of the main pollutant both in oilfield exploitation and petrochemical enterprises. Based on oily sludge treatment situation at home and abroad, the fruition of research on the oily sludge reduction,harmless,recycling treatment of oily sludge were summarized in this paper, which focus on pyrolysis technology of oily sludge. The factors influencing oil sludge pyrolysis were analyzed, such as reaction temperature, reaction time, heating rate, etc.Pyrolysis of oil sludge can be considered the coupled water drying and oil thermal decomposition processes.According to water content of the sludge accounted for 62.72%, to realize the oily sludge reduction, the drying of oil sludge pyrolysis was studied first. The drying curves and the drying rate curves were obtained from the experiments. The methods of time computation in drying under this condition with mass transfer equations are described, the constant rate drying phase, the first falling rate drying phase and the second falling rate drying phase of time were 10.5min,40min and 65min. The experimental data of drying kinetics for oily sludge were treated with some common kinetics model. The new equation model was coincided with the experimental data well.According to oil content of the sludge accounted for about 28%, to realize recycling treatment of oily sludge, then the pyrolysis of oil sludge rate of 97.57% was obtained. The thermal gravimetric analysis of oil sludge pyrolysis was studied, based on principles of low temperature pyrolysis of oil and the integral treatment of equation, the mechanism equations were obtained, so the activation energy, reaction order and frequency factor were obtained from the lines regression. The experimental results show that there are three temperature ranges in the organic matter pyrolysis phases:180℃～250℃,250℃～450℃,450℃～480℃. In the second phases, the activation energy, reaction order and frequency factor of the corresponding pyrolysis reaction for oil sludge were 17.44 kJ/mol,0.2 and 1.09×104min-1 respectively. In the third phases, they were 38.24 kJ/mol,0.4 and 1.19×104min-1 respectively. In the second and third phases, the fitting kinetic parameters obtained are consistent with the related reference data. The variation of pyrolysis rate with time based on the kinetic equation coincided with the experimental data well, this show the pyrolysis study is reasonable, and these results are very useful for the future research for the pyrolysis of oil sludge.