Research Progress of Automotive Spraying Organic Waste Gas Treatment Technology

Abstract: This paper discusses the sources, hazards and ways of emission reduction of organic waste gas in the process of automotive coating. Several kinds of waste gas treatment such as adsorption, combustion, cryocondensation, activated carbon adsorption-catalytic combustion and biological treatment are introduced Technology, and to be compared, with a view to provide theoretical reference and basis for the effective treatment of organic exhaust gas in the automotive coating industry in the future.

Spraying is one of the most important processes in the automobile manufacturing and maintenance industry, and it is also the process that produces the most gas.

With the implementation of new environmental protection laws and regulations such as the "Environmental Protection Law" and the "Air Pollution Prevention and Control Law" more stringent requirements are imposed on the quality of the atmospheric environment and the treatment of enterprises' exhaust gas in our country. How to take effective measures to deal with the spraying of exhaust gas and reduce the emission of VOCs is a question that every automobile manufacturer / maintainer should consider.

1 spray the main source of exhaust gas

Spraying the exhaust gas from the main exhaust any paint containing volatile organic solvents in a spray drying process and volatile mist generated, called volatile organic compounds (of VOCs), mainly composed of benzene, toluene, xylene and the like. In general, the use of coating, top coating and cleaning solvents produced the highest VOCs content. Specific to the production workshop, have the largest production of organic waste spray booths, air-conditioned room, paint room, drying room, etc., and different plant exhaust gas composition is not the same. Liu Yu Cong, et al. The chemical composition analysis of VOCs in light vehicle coating Ding Yi process showed that the main chemical components of VOCs in the coating process were aromatic hydrocarbons and OVOCs such as ethyl acetate, butyl acetate and propylene glycol methyl ether acetate substance.

2 spray exhaust hazards

Spraying paint organic solvents toxicity, spraying benzene, xylene and other volatile to the workshop air, the operator and the natural environment are harmful. Exhaust gas inhalation can cause poisoning after inhalation, is now recognized as a strong cancer. Long-term inhalation of low concentrations of spray paint will cause cough, chest tightness, asthma and other chronic respiratory diseases, seizures occur in severe cases, coma; inhalation concentration greater than 1500mg / m3 of benzene vapor, can cause aplastic anemia. In addition, organic waste gas plays an important role in photochemical smog pollution and the formation of acid rain. Therefore, enterprises have the responsibility and obligation to take effective measures to reduce emissions and deal with technology to reduce emissions and reduce the harmful substances on human health and environmental quality hazards.

3 spray exhaust emission reduction approach

3.1 Use of environmentally friendly paint

Green paint is in line with national environmental labeling products proposed technical requirements of the paint products, with low VOC content, energy saving, zero pollution and so on. In general, environmental coatings are divided into water-based paint, solvent paint and powder paint. Solvent coating solvents are mostly toluene, xylene, esters, alcohols, the final VOCs in the form of volatile to the atmosphere; water-based paint solvent water accounted for more than 85%, less organic solvents; and powder coatings from the polymer , Pigments and additives, the total coating can be recycled during the spraying process, the amount of VOCs produced is very little, the environmental damage is very small, and the amount of VOCs emitted by the powder coating is far lower than that of the liquid paint P1. Since HLCAT293-2006 came into force in 2006, automobile paint sprays on the market have started to transition from solvent-borne coatings to water-borne coatings. Environmentally friendly powder coatings such as diatom mud products Activated carbon wall materials such as environmental pollution is minimal.