Smog Chamber Simulation Of Atmospheric Photochemical Reactions Of 1,3-butadiene And NO_x

This article uses the experiment system of smoke chamber to verify the conversion process of volatile organic compounds and the final products.The typical pollutant1,3-butadiene emitted by the pharmaceutical industry was selected as the research object,and studied the main processes of forming photochemical smog in the atmosphere by1,3-butadiene and Nitrogen dioxide.Then using a Fourier infrared analyzer analyzed the gas phase products produced by C₄H₆-NO_x photochemical reaction,and combined with MCM mechanism,numerical simulation by FACSIMILE software to further study the process and characteristics of 1,3-butadiene conversion to SOA.The regular model of the formation of the main products of C4H6-NOx photochemical reaction:ozone and secondary organic aerosol,which were affecting by the intensity of light and the initial concentration ratio of the reactants these two influencing factors was given.The results of 1,3-butadiene photochemical reaction experiments show that the change of UV intensity and initial concentration ratio of reactants can have an important effect on the reaction.Under the irradiation of ultraviolet light,1,3-butadiene and NO₂ undergo a series of photochemical reactions to form a large amount of O₃ and SOA particles.The UV intensity is positively correlated with the decomposition rate of 1,3-butadiene,the maximum concentration of O₃ produced,and the concentration of SOA particles.The increase in UV intensity can shorten the time for the gaseous/particulate product to reach equilibrium and promote the rapid conversion of 1,3-butadiene to SOA particles.The increase of the initial concentration ratio of the reactants will increase the particle size scale and the number concentration of the generated SOA particles,and the maximum value of the generated O₃ concentration and the maximum concentration of the SOA particles are positively correlated with the ratio.The gas phase products were mainly analyzed with FT-IR and found to be formaldehyde,acetaldehyde,ozone,carbon monoxide,carbon dioxide,acrylic acid,ketones and esters.Combining the MCM mechanism,the FACSIMILE software was used to simulate the conversion process of 1,3-butadiene to SOA.From the formation of simulated products formaldehyde and acrolein,it was verified that a large amount of SOA particles in the reaction system were mainly formed by the reaction of 1,3-butadiene and O₃,and concluded that 1,3-butadiene is a precursor for the formation of SOA in a simulated experimental environment which has a high SOA production potential.