螺[4,5]-癸烷和螺[5,6]-十二烷燃料热解机理及反应动力学研究  

Study on pyrolysis mechanism and kinetics of spiro[4,5]decane and spiro[5,6]dodecane

作　　者：王鸿燕 孙欣悦[1] 周雨柔 刘国柱 王宇桐[3] 曹景沛 WANG Hongyan;SUN Xinyue;ZHOU Yurou;LIU Guozhu;WANG Yutong;CAO Jingpei(Jiangsu Province Engineering Research Center of Fine Utilization of Carbon Resources,China University of Mining&Technology,Xuzhou 221116,China;School of Chemical Engineering and Technology,Key Laboratory for Green Chemical Technology of Ministry of Education,Tianjin University,Tianjin 300072,China;College of Chemical Engineering,Shenyang University of Chemical Technology,Shenyang 110142,China)

机构地区：[1]中国矿业大学江苏省碳资源精细化利用工程研究中心,江苏徐州221116 [2]天津大学化学工学院教育部绿色化学技术重点实验室,天津300072 [3]沈阳化工大学化工学院,辽宁沈阳110142

出　　处：《燃料化学学报（中英文）》2024年第7期1020-1034,共15页Journal of Fuel Chemistry and Technology

基　　金：江苏省自然科学基金(BK20221134);国家自然科学基金(22208371);江苏省双创博士(JSSCBS20221514)资助。

摘　　要：采用B3LYP/6-311++G(d,p)和反应性分子动力学方法,对螺[4,5]-癸烷(C_(10)H_(18))和螺[5,6]-十二烷(C_(12)H_(22))的热解机理进行研究,揭示不同碳环结构和尺寸效应对燃料初始分解反应活性及小分子和芳烃产物生成行为的影响。结果表明,两种螺环烷烃燃料初始分解路径相似,均通过单分子碳碳键解离发生开环异构反应和小分子自由基进攻燃料母体的氢提取反应而消耗。相较于C_(10)H_(18),C_(12)H_(22)中分子张力更大的七元环使速控步碳碳键及碳氢键能更低,导致燃料呈现出更低的初始分解温度和更高的反应活性。两种螺环燃料初始分解产生的自由基进一步影响了C1−C7小分子烃类和环烯产物的生成。其中,乙烯的生成始终占据主导地位。由于螺环尺寸效应的影响,链烃和环烯烃的生成表现出明显的结构差异性。对于C_(10)H_(18)分解而言,生成大量的五元环烯产物,包括环戊二烯、环戊烯、富烯、甲基环戊二烯和甲基环戊烯;而C_(12)H_(22)中更大的七元环结构,将生成对应的七元环烯产物(环庚烯、亚甲基环庚烷)。ions by small radicals attacking the fuel parents.Due to the lower C−C and C−H bond dissociation energies caused by large tension of the seven membered ring structure,C_(12)H_(22) may exhibit the lower initial decomposition temperature and higher reaction activity than C10H18.The differences of simultaneously formed fuel radicals during C_(10)H_(18) and C_(12)H_(22) initial pyrolysis further affect the formation pathways of C_(1)−C_(7) small products,cycloalkenes and monocyclic aromatics.Among them,ethylene are the most important products.Due to the presence of inherent six membered rings in two spiro-fuels,monocyclic aromatics mainly originate from multi-step dehydrogenation reactions of fuel radicals,involving benzene,toluene,styrene and ethylbenzene.Notably,the size effect of spiro-ring in two fuels leads the obvious structural differences of the formation of chain hydrocarbons and cycloalkenes.For C_(10)H_(18),a large number of penta-cycloalkenes may be generated,including cyclopentadiene,cyclopentene,fulvene,methylcyclopentadiene and methylcyclopentene,whereas the seven-membered ring structure of C12H22 may produce corresponding seven-membered products(cyclohexene and methylene cycloheptane).Moreover,the pyrolysis behaviors of these two spiro-fuels at 2000 K based on the ReaxFF molecular dynamics simulation were explored and show well consistent with the main products derived from DFT theoretical calculations.This work performs the DFT theoretical calculations and ReaxFF molecular dynamics simulation on the pyrolysis kinetic mechanisms of two representative high-density biomass fuels of spiro fuels,providing a possible initial pyrolysis path and laying a theoretical foundation for their practical application in engines.However,the complex working environment of the cooling channel poses more challenges to the actual pyrolysis process of the new high-density hydrocarbon fuels.In future research,pyrolysis experiments will be conducted under high temperature and high pressure conditions,and the detailed p

关 键 词：螺环烷烃高密度燃料 热解机理 反应动力学 密度泛函理论 

分 类 号：TQ203[化学工程—有机化工] TQ517