Coating Types-based Volatile Organic Compounds Emission Characteristics And Environmental Impact In Furniture Manufacturing Industry

With economic development and social progress,the emission characteristics of the furniture manufacturing industry have undergone major changes,and the existing research results can no longer reflect the current situation of the industry.In order to explore the differences in the emission characteristics of volatile organic compounds(VOCs)from different coating types,including solvent-based,solvent-based ultra-violet(UV),water-based,waterbased UV and powder coating,this study selected 8 furniture manufacturing companies for onsite monitoring.The VOCs emission characteristics,environmental impacts,health risks of different coating types,and environmental benefits after replacement of low-VOCs-content coatings were analyzed.The main conclusions are as follows:The main components of the same coating type at different monitoring points,including workshops and stacks,are relatively consistent,while the emission characteristics of different coating types are significantly different.Aromatic hydrocarbons account for the highest proportion of solvent-based coating,and the main components are m/p-xylene,butyl acetate and styrene.Solvent-based UV coating is dominated by aromatic hydrocarbons and oxygenated volatile organic compounds(OVOCs),and the main components are m/p-xylene,butyl acetate and toluene.OVOCs account for the highest proportion of water-based coating,such as methylal and propylene glycol monomethyl ether acetate.OVOCs account for the highest proportion of water-based UV coating,and the main components are butyl acetate,propylene glycol monomethyl ether acetate and vinyl acetate.OVOCs account for the highest proportion of powder coating,and the main component is ethyl 3-ethoxypropionate.The ozone formation potential(OFP)and secondary organic aerosol formation potential(SOAFP)at each monitoring point are as follows:solvent-based coating>solvent-based UV coating>water-based coating>powder coating>water-based UV coating.Among the different monitoring points,aromatic hydrocarbons contribute the most to the OFP of solvent-based,solvent-based UV,water-based and powder coating,and OVOCs and aromatic hydrocarbons contribute the highest to the OFP of water-based UV coating.The highest contributor to the SOAFP of exhaust gas from solvent-based,solvent-based UV,water-based,water-based UV and powder coating are aromatic hydrocarbons.In solvent-based coating,there are carcinogenic risks from ethylbenzene,dichloromethane and 1,2-dichloroethane at each monitoring point.Ethylbenzene has the largest carcinogenic risk,reaching 1.49×10-5.In the solvent-based UV coating,there is a carcinogenic risk of ethylbenzene at each monitoring point.Water-based,water-based UV and powder coating are not carcinogenic.The hazard quotients of the solvent-based coating in spraying workshop and the inlet of the exhaust tube are 1.35 and 2.04,respectively.The hazard quotients of solventbased coating waste gas from other monitoring points and other coating types at all monitoring points are less than 1.In the case of the same exhaust gas treatment efficiency,the coating type with the highest reduction of O3 after the low-VOCs-content coatings replace the solvent-based coating is powder coating,and the coating type with the highest reduction of SOA is water-based UV coating.Using water-based coating instead of solvent-based coating,when the exhaust gas treatment efficiency of solvent-based coating does not exceed 60%,at least 0.29 kg O3 and 2.39 g SOA can be reduced.Using water-based UV coating or powder coating instead of solventbased coating,when the exhaust gas treatment efficiency of solvent-based coating does not exceed 90%,at least 0.02 kg O3 or 0.07 kg O3 can be reduced,and when treatment efficiency does not exceed 95%,at least 0.57 g SOA or 0.34 g SOA can be reduced.