Study On Product Characteristics And Distribution Of Chlorine Element In Microwave Co-pyrolysis Of Wood Sawdust And Polyvinyl Chloride

This paper studied the microwave pyrolysis of polyvinyl chlorine（PVC）and sophora wood（SW）.The microwave pyrolysis of PVC at different temperatures,the microwave co-pyrolysis of PVC-SW at different temperatures and the microwave pyrolysis of mixing ratios and three organic components of of biomass（Cellulose,hemicellulose and lignin）and PVC were conducted in a microwave reactor under nitrogen atmosphere.The effects of different parameters on product characteristics and the distribuction of chlorine in pyrolysis products were investigated.Microwave pyrolysis is a more cutting-edge,simpler and more efficient pyrolysis technique with better heating uniformity and process controllability than traditional heating.The results revealed that the addition of SW significantly reduced the CO₂ yield in the pyrolysis gas products and greatly increased the production of CO components that can be used as natural gas,and the chlorine emissions was suppressed from59.07%to 28.09%,effectively curbing the generation and release of harmful gaseous substances compared with the pyrolysis of PVC.The addition of SW also greatly improved the yield and quality of pyrolysis oil.The content of chlorine-containing compounds could be suppressed to<1%at low temperature（<550 ^oC）and the chlorine content in the carbon product was increased from0.33%to 4.72%.Cellulose,hemicellulose and lignin were co-pyrolyzed with PVC under microwave radition respectively.The results showed that among the three organic components of biomass,lignin had the most significant effect on reducing gas-phase chlorine emission and realizing chlorine fixation in char products,and chlorine was mainly fixed in the form of Na Cl and organochlorine in the lignin-PVC co-pyrolysis.In addition to the influence of sodium on chlorine,lignin was still the best organic component in biomass for chlorine fixation,and hemicellulose and lignin had similar effect on chlorine fixation.Therefore,co-pyrolysis of lignin-rich and hemicellulose biomass and PVC can achieve HCl emission reduction,efficient retention of chlorine in char and significant improvement in the characteristics of three-phase products.This is a harmless and efficient waste treatment method,which has a good reference significance for the selection of solid waste treatment methods in the future.