Numerical Simulation Of The Reaction Network And Mechanism Of Ethylene To Form Benzene

The secondary reaction of ethylene,propylene and butadiene products of steam pyrolysis produces polycyclic aromatic hydrocarbons,tar,and even Coke,which not only consumes the product of the purpose,but also has a greater impact on the production cycle of pyrolysis devices.Considering that the secondary reaction network is very large and involves many free radical reactions,this paper only studies the secondary reaction mechanism of benzene produced by various reaction pathways using ethylene as the reaction material.Firstly,based on the literature review,it is considered that ethylene undergoes the addition reaction of free radicals+olefins or free radicals+alkyne to form large free radicals,and the radicals continue to undergo cyclization and dehydrogenation to benzene.The required activation energy is low,so it is considered that the ethylene side reaction network should be reacted in the above manner.Secondly,by comparison with the literature data,it is speculated that all the free radical reactions that may occur in the ethylene benzene side reaction network are obtained.The third use of Materials The kinetic data of the above-mentioned radical element reaction was obtained by simulation of the molecular simulation software.Fourthly,the above kinetic data was input into the one-dimensional tube cracking furnace constructed by Aspen Plus software,and the process simulation calculation was repeated to obtain the ethylene deputy.Producting distribution of the reaction network.In order to further verify the correctness of the ethylene benzene side reaction network,the above reaction network was changed to a ethane primary and secondary reaction network including an ethane primary reaction system and an ethylene side reaction network.Ethane is used as raw material,and the product distribution of benzene is formed through a series of reactions,and the product distribution is compared with the industrial cracking data of ethane.Finally,the simulation results are in good agreement with the industrial data.The calculation results show that there are two main routes for the formation of benzene from ethylene:one path is C₂H₃·the addition reaction with ethylene to form1-C₄H₇·-4,and then cyclization to form C₆H₁₁·,and then dehydrogenation and transfer to produce benzene;Another path is C₂H₃·addition with acetylene to form1,3-C₄H₅·-4 and C₂H₃·decompose into acetylene,acetylene chain is transferred to C₂H·,C₂H·and ethylene are added to 1-C₄H₅·-4,1-C₄H₅·-4 isomerized to 1,3-C₄H₅·-4,and 1,3-C₄H₅·-4 is cyclized with ethylene to C₆H₉·by the above two methods,and then dehydrogenated and finally produced to form benzene.When ethane is industrially cracked to form benzene,due to the shallow depth of reaction,only C₂H₃·is reacted with ethylene to form 1-C₄H₇·-4,which is then cyclized to form C₆H₁₁·,which is then dehydrogenated and passed to form benzene.There is only one route,not related to acetylene.