Interpretation of VOCs emission standards in Shandong furniture manufacturing industry.

Part 3 of the Volatile OrganicS Emission Standard: Furniture Manufacturing Industry (hereinafter referred to as "Standards") has been approved by the Shandong Provincial Government and officially issued by the Provincial Environmental Protection Department and the Provincial Quality Supervision Bureau, and will be implemented from September 3, 2017, which is part 3 of the Series Emission Standards for Volatile Organics in Shandong Province. In order to facilitate the public to fully understand the background of the standard preparation, main ideas, technical feasibility, etc. , is to do the following interpretation.
, "standard" preparation background
volatile organic compounds (VOCs) is an important precursor to urban haze and photochemical smoke, mainly from chemical production, fuel
coatings
manufacturing, solvent use and other processes, some VOCs have carcinogenic, mutation, teratogenic effect, can directly cause harm to human health.
the coating process of furniture manufacturing industry belongs to the use of solvents and is an important source of VOCs emissions in ambient air. Our province is a major province of furniture industry, the main business income of enterprises above the scale accounted for 12% of the country, of which the total output value of solid wood furniture ranked first in the country. The surface coating process of furniture in our province uses a wide variety of coatings and organic solvents and large amount of dosage, most enterprises production workshop and paint storage workshop closed poor, and can not be equipped with effective pollution control facilities, resulting in VOCs emissions, and non-organized emissions mainly. Therefore, it is of great significance to set the VOCs emission standard of furniture manufacturing industry to control pollution and improve the quality of atmospheric environment.
, the characteristics of VOCs emissions in the furniture manufacturing industry
the types of VOCs in the furniture manufacturing industry are related to the type of coatings. When coated with the same area, the use of oil-based coatings produced the most VOCs,
water-based coatings
second,
powder coatings
the least. The production process of furniture manufacturing enterprises in our province mainly uses polyurethane coatings, nitro-type coatings, alcoholic acid coatings and other oily coatings, VOCs emissions are larger. VOCs emissions from furniture manufacturing are also related to coating technology. When coated with the same area, air spray technology produces the most VOCs, and processes such as electrostatic spraying and brushing produce fewer VOCs. Most of our province's furniture manufacturing enterprises to air spraying-based, in the furniture production process needs to carry out a number of primers and paint spraying operations, resulting in low use of paint, VOCs emissions. The VOCs emissions of furniture manufacturing industry also have a lot to do with the closedness of the workshop and the measures of end management. Most of the furniture manufacturing enterprises in our province's production workshop for the semi-closed form, production equipment distribution is not concentrated, some enterprises only on the pollution is more concentrated, more serious painting stations, drying stations and other stations generated by the exhaust gas collection and treatment, and most of the organic exhaust gas is still in the form of unorganized emissions. And a considerable number of enterprises did not take any end-of-life governance measures, some enterprises only install water absorption and other simple VOCs governance facilities, the VOCs processing efficiency is low, resulting in voCs emissions.
, the current furniture manufacturing industry feasible VOCs waste gas pollution prevention and control measures
furniture manufacturing industry coating VOCs waste gas treatment can be divided into two ways of prevention and treatment. "Anti"is mainly source control, that is, by increasing the low organic solvent content of environmental protection coatings (water-based coatings or powder coatings) use ratio, improve coating technology (spin cup atomized electrostatic spraying, air atomized electrostatic spraying, brush ingenuity, rolling, etc.), research and development of intelligent coating test lines, coating workshop fully closed and other methods to reduce VOCs production. "Treatment" is mainly for the coating production process produced by VOCs waste gas collection and purification treatment. Combined with the field research of typical furniture manufacturing enterprises in the province and the results of various types of furniture manufacturing enterprise data research, the more efficient treatment measures of VOCs exhaust gas in furniture manufacturing mainly include water absorption and activated carbon adsorption combination process, thermal catalytic combustion (RTO) and so on.
from the level of coating technology, pollution control technology and research and data of furniture manufacturing enterprises in our province, enterprises can take raw material adjustment, improve spraying technology or spraying technology, supporting efficient pollution control facilities and other ways to achieve the emission standards.
4. The main idea of standard-setting
standards according to the toxicity of pollutants, photochemical reaction characteristics and detection concentration and other factors, the comprehensive selection of benzene, toluene, xylene and VOCs as control factors.
the number of furniture enterprises in our province, the scale and management level of the difference is large, the standard set two time periods for existing enterprises, set aside about a year for the transformation of coating process and processing facilities. From the date of implementation of the standard until 31 December 2017, existing enterprises will implement emission limits for the period I. From the date of the implementation of the standard, the existing enterprise will implement the emission limits for the second period from January 1, 2018.
this standard sets the maximum allowable emission concentration limit, the maximum allowable emission rate limit and the plant control point emission limit, which can be controlled from the emission concentration, emissions and unorganized emissions of pollutants. Benzene is more toxic, usually the enterprise emissions can not detect the pollutant, so the benzene I period emission concentration limit is set at 1.0mg/m3, the second period emission limit severed to 0.5mg/m3. Toluene and xylene are common in coatings used by enterprises, and the properties of the two pollutants are similar, the combined control of the toluene-dychbenzene i period emission concentration limit sits at 40mg/m3, the emission limit of the second period is tightened to 20mg/m3. Combined with the actual emission status of our province and reference to other provincial and municipal standards, the emission concentration limit of THE second period of VOCs was determined to 80mg/m3, and the emission limit of the second period was tightened to 40mg/m3. In view of the fact that the emission of VOCs in the furniture industry is closely related to the type of paint, coating process and environmental management level, the corresponding process operation and production management requirements are put forward in the standard, and the emission limits of the monitoring points of the factory are put forward.
V. The role of standard implementation
(i) promote technological progress and raise the level of pollution control. Through the formulation and implementation of this standard, will promote furniture manufacturing enterprises in our province to continuously improve the production process, improve the level of VOCs pollution control, improve the overall competitiveness of enterprises.
(ii) control pollution and improve the quality of the atmospheric environment. According to the current emission concentration of enterprises, the average emission reduction of VOCs was 77%, especially with significant impact on air quality, such as toluene and xylene emissions were significantly reduced, and environmental benefits were significant.
(iii) strengthen environmental management and improve the standard system. At present, China has not promulgated the VOCs emission standards for the surface coating industry, only in the national "comprehensive emission standards for atmospheric pollutants" (GB16297-1996) stipulated more than ten species of VOCs emission limits, such as benzene, toluene, xylene, but its existence of fewer control factors, more relaxed emission limits, monitoring methods, control requirements and other issues. The establishment of VOCs emission standards in furniture manufacturing can provide a basis for controlling VOCs pollution in furniture manufacturing industry, strengthen environmental management and improve the standard system.