Molecular Simulation Research On Pyrolysis Mechanism Of Mixed C4 Hydrocarbon

At present,cracking materials appears relative shortage,the conventional cracking materials cannot meet the needs of industrial production.Therefore,how to find the new cracking materials become the new topic what ethylene industry development face with.Mixed C4 hydrocarbon is the main by-product in catalytic cracking and steam thermal cracking equipment of oil refinery.The yield of the mixed C4 hydrocarbon accounted for 40%of ethylene.So,more and more researchers mix the mixed C4 hydrocarbon with naphtha serve as cracking materials,whether is suitable for the mixed C4 hydrocarbon serve as cracking materials needs assessment.However,adopt the method of experiment to assess cracking materials need a lot of manpower and material resources,and need a lot of time and investment cost.In recent years,with the development of computer technology,molecule simulation technology play a very important role in research of chemical reaction mechanism.Molecule simulation technology can be used to research the path of the chemical reaction.search the transition state,study the chemical reaction mechanism.The molecular simulation technology is applied to the reaction mechanism of hydrocarbon cracking in this text.The reaction mechanism is analysed and the product distribution is forecasted in the major components of the mixed C4 hydrocarbon.First of all,employ the Materials Studio software to simulate every free radical reaction of n-butane,isobutane,1-butylene and isobutene in mixed C4 hydrocarbon.The activation energy and reaction rate constant of every reaction are got,which compare the experiment data from literature.The results show that the error of simulation and experiment data is under 10%.The great error in the data is analysed,the simulated result is reliable.Secondly,the reaction path of n-butane,isobutane,1-butylene and isobutene is deduced from the simulation data,and get the product distribution of the frist reaction of each molecule.The results show that the formation of ethylene was the most probable,the yield of ethylene was higher than propylene and butylene in the pyrolysis of n-butane;The formation of isobutylene was easier than propylene in the pyrolysis of isobutane,the formation of ethylene was not found in the first pyrolysis reaction of isobutane.The yield of objective product from high to low is butadiene,propylene,ethylene in the first pyrolysis reaction of 1-butylene;Isobutene only generate propylene,other olefins cannot produce in the first pyrolysis reaction of isobutene.The product distribution of every molecule in the first pyrolysis reaction coincide with the experimental laws.The molecular simulation method is applied to the reaction mechanism of hydrocarbon cracking is feasible in this text.