蒙脱石对油页岩干酪根热解特性的影响

选取中国桦甸、抚顺、窑街3个地区油页岩,酸洗得到各干酪根样品。应用TG-FTIR技术对不同升温速率下各干酪根与蒙脱石共热解行为进行了研究,并利用Coats-Redfem积分法对升温速率为10℃/min下的干酪根掺混样品进行热解反应动力学分析,获得了蒙脱石对干酪根热解产物析出规律的影响及热解过程的活化能(E)和指前因子(A).结果表明,随着蒙脱石掺混比例增大,桦甸和抚顺干酪根热解失重率先升高后降低;在热解过程中,440℃前干酪根与蒙脱石掺混样品的热解失重率较干酪根单独热解低,而440℃后其热解失重率较干酪根热解有所提高;蒙脱石掺混比例增大使得各干酪根热解产物中CH₃/CH₂值有所增加;有蒙脱石掺混的干酪根热解活化能相比干酪根热解活化能有所降低。表明蒙脱石对油页岩干酪根热解具有物理吸附和裂解催化两种作用,且随着热解过程的加深和蒙脱石配比的改变而不同。最后,对升温速率为10℃/min的样品进行了热解反应动力学分析,进一步探讨了蒙脱石对干酪根的热解影响机理。

Effect of smectite on the pyrolysis of kerogen isolated from oil shale

To examine the effect of smectite on oil generation of kerogen pyrolysis,we studied the kerogen isolated from oil shale of Huadian,Fushun and Yaojie by TG-FTIR and kinetic analysis. Results show that the weight loss of kerogen from Huadian and Fushun are reduced after the initial increase. Furthermore,the weight loss of kerogen which blended with smectite is lower than that of kerogen until the pyrolysis temperature reaches 440℃,but it then increases rapidly and exceeds that of kerogen after 440℃。 With the increase of smectite,the ratio of CH₃/CH₂ is also increased at same heating rate. The pyrolysis activation energy of kerogen with smectite is found lower than that of kerogen alone. Results show that the effect of smectite to kerogen pyrolysis is both physical adsorption and catalytic cracking,which will be different through the pyrolysis process and increasing blend of smectite. Finally,further discuss has been conducted for the mechanism of smectite by pyrolysis kinetics analysis of samples with a heating rate of 10℃/min.