Experimental And Kinetic Modeling Studies Of 2-ethylfuran Pyrolysis

Energy shortage and environmental pollution have brought great challenges to human life.Alternative energy sources,especially biomass fuels,may reduce the use of fossil energy and greenhouse gas emissions.In recent years,with the development of the conversion of furan series biofuels from biomass,furan series biofuels have attracted great attention.Among them,2-ethylfuran（EF2）,as a new type of furan fuels,has great application potential.Before the commercial application of EF2,it is necessary to conduct relevant experimental and theoretical studies on its combustion properties.Therefore,in this paper,EF2 was selected as the research object,and the detailed pyrolysis chemical kinetics model was constructed,which was compared with the pyrolysis process of 2-methylfuran and 2,5-dimethylfuran,and the influences of branch structure and branch numbers on the pyrolysis process of furan fuels was studied.The work was mainly conducted from experiments and kinetic modeling.The pyrolysis experiment of flow reactor at low pressure and normal pressure was carried out based on the device of combustion and flame BL03U endstation in the National Synchrotron Radiation Laboratory of the University of Science and Technology of China.Synchrotron vacuum ultraviolet photoionization mass spectrometry（SVUV-PIMS）was used to detect and measure the pyrolysis intermediate species and products.Several radicals and stable species in EF2pyrolysis were detected and quantified,including methyl,propargyl,vinylketene,furan,2-methylfuran,2-vinylfuran,benzene,toluene,and naphthalene,etc.Mole fraction profiles vs.temperature in pyrolysis was achieved.In terms of kinetic modeling,a comprehensive EF2 pyrolysis model was updated and validated against the experimental data.The present model could reproduce the results of most pyrolysis species within the experimental uncertainty at both low and atmospheric pressures.Based on sensitivity analysis and rate of production analysis,kinetic analysis of key important species and important reactions were conducted to analyze the main reaction pathways in EF2 pyrolysis.It could be concluded that the unimolecular decomposition to produce 2-furylmethyl,H-abstraction by H-atom and methyl to produce 1-（2-furyl）ethyl,and H-addition reactions to produce vinylketene,furan and 1-penten-1-yl contribute overwhelmingly to EF2 consumption at both pressures in EF2 pyrolysis.In this work,the ethyl side chain of EF2 leads to a key C–CH₃ bond dissociation pathway in the decomposition of the fuel,which is a unique decomposition pathway compared with 2-methylfuran and 2,5-dimethylfuran.2-Vinylfuran,2-furylmethyl and vinylketene are key species in EF2 pyrolysis.Aromatic products are observed with lower concentration levels in EF2 pyrolysis compared with those in 2-methylfuran and 2,5-dimethylfuran pyrolysis.With lower mole fractions of C3 and C4 species in pyrolysis,EF2 has a tendency to produce less aromatic soot precursors than 2-methylfuran and 2,5-dimethylfuran.