N_2/CO_2气氛下含油污泥热解特性实验研究

Experimental investigation on pyrolysis characteristics of oil sludge in N_2/CO_2 atmosphere

含油污泥成分复杂、性质变化大、有毒物质含量高，可采用热解技术实现减容无害化处罪。基于热重一红外联用分析仪（TGFTIR）研究了某含油污泥在N2／CO2气氛下的热解特性。结果表明：含油污泥热解过程主要分为低沸点烃类物质（300～500℃）的析出、无机碳酸盐（500～800℃）以及重质油等长链稳定有机大分子（900～1100℃）的分解3个阶段；利用Coats—Redfern方法，求得含油污泥主要热解阶段的动力学参数，发现高温段的活化能高于中、低温段；N2／CO2气氛对中、低温段热解过程影响不大，但是在CO2气氛下高温段的活化能明显增加；热解产物FTIR分析得出其析出气体主要以CO2、CO以及CH4等轻质气体为主；在高温段，有大量的甲基化合物析出，且CO2气氛对其生成有明显的促进作用。

The pyrolysis characteristics of oil sludge was investigated using thermogravimetric analysis-Fou- rier transform infrared spectrometer （TG-FTIR） in N2/CO2 atmosphere. It was found that the pyrolysis process could be divided into three main stages, corresponding to the light hydrocarbons devolatilization （300 ℃～500 ℃）,carbonates decomposition （500 ℃～800℃）,and stable macromolecular structure of or- ganic matter decomposition （900 ℃ ～1100 ℃）. The Coats-Redfern method was applied to calculate the ki- netic parameters of the main stages of oil sludge pyrolysis, and the results show that the activation energy was much higher in the high-temperature stage. The CO2 atmosphere had no obvious influence on the oil sludge pyrolysis for both low-temperature and middle-temperature stages, but in high-temperature stage, the activation energy in CO2 atmosphere obviously increased compared to N2 atmosphere. By FTIR analy- sis,it was found that the major volatile gases released from oil sludge pyrolysis mainly composed by CO2, CO,CH4 ,and other hydrocarbons. In the high-temperature stage, there was a large amount of methyl re-lease,which was dramatically promoted by CO2 atmosphere.