Fischer-Tropsch合成油正构烷烃尿素络合物非等温热分解动力学  

Non-isothermal thermal decomposition kinetics of n-alkane-urea inclusion compounds from Fischer-Tropsch synthesis oil

作　　者：于婉秋 韩冬云[1] 石薇薇[1] 乔海燕 曹祖宾[1] 朱衣点 Yu Wanqiu;Han Dongyun;Shi Weiwei;Qiao Haiyan;Cao Zubin;Zhu Yidian(College of Petrochemical Engineering,Liaoning Shihua University,Fushun Liaoning 113001,China;Jiangsu Sailboat Petrochemical Co.,Ltd.,Lianyungang Jiangsu 222000,China)

机构地区：[1]辽宁石油化工大学石油化工学院,辽宁抚顺113001 [2]江苏斯尔邦石化有限公司,江苏连云港222000

出　　处：《石油化工》2021年第2期130-136,共7页Petrochemical Technology

基　　金：辽宁省教育厅基本科研项目(L2017LQN013)。

摘　　要：以Fischer-Tropsch合成轻馏分油(F-TLD)为原料,正壬烷(C_(9))和正十二烷(C_(12))为参照,采用尿素络合法分离油品中的正构烷烃。利用FTIR和TG-DTG手段研究了尿素络合物(UIC)在氮气氛围中的固相热分解动力学,同时以不同碳链长度正构烷烃尿素络合物(C_(9)-UIC和C_(12)-UIC)的动力学结果作参照,采用Coats-Redfern法和Doyle法求取相关参数并确定反应机理。实验结果表明,F-TLD-UIC与C_(9)-UIC,C_(12)-UIC的热分解动力学研究结果具有一致性;UIC在氮气氛围中的热分解反应为一级反应,属于以Avrami-Erofeev的随机成核和随后生长机理为控制步骤的A1机理;用相关性较好的Doyle法求得F-TLD-UIC,C_(9)-UIC,C_(12)-UIC的热分解活化能分别为104.56,115.28,118.97kJ/mol,F-TLD-UIC的热力学参数焓变、熵变及摩尔自由能分别为101.50kJ/mol,-73.95J/(mol·K),128.75kJ/mol。Taking n-nonane(C_(9))and n-dodecane(C_(12))as references,n-alkanes were separated by urea inclusion method from Fischer-Tropsch synthesized light distillates(F-TLD).The thermal decomposition kinetics of urea inclusion compounds(UIC)and the referred n-alkanes-UIC with different carbon chain lengths such as C_(9)-UIC and C_(12)-UIC,were all studied by FTIR and TG-DTG in nitrogen atmosphere.Coats-Redfern and Doyle methods were applied to calculate the related parameters and deduce the possible mechanism of the thermal decomposition reaction.The results show that the thermal decomposition kinetics of F-TLD-UIC is consistent with that of C_(9)-UIC and C_(12)-UIC,which follows the first order.It is showed that the process is quite agree with A1 mechanism,namely,a random nucleation and subsequent growth mechanism of Avrami-Erofeev as the control step.Solving by Doyle method,the data indicate that there is a good correlation.The thermal decomposition activation energy of F-TLD-UIC,C_(9)-UIC and C_(12)-UIC has been deduced to be 104.56,115.28 and 118.97 kJ/mol,respectively,while the enthalpy,entropy and Gibbs free energy of the decomposition of F-TLD-UIC is 101.50 kJ/mol,-73.95 J/(mol·K)and 128.75 kJ/mol,respectively.

关 键 词：尿素络合 Fischer-Tropsch合成油 正构烷烃 热解 动力学 热力学 

分 类 号：TQ529.2[化学工程—煤化学工程]