With the increasing demand of domestic automobile market, the automobile industry develops rapidly. The rubber processing industry provides automobile manufacturers with rubber products such as tires, hose, tape, oil seal, sealing strip, shock absorber, leather bowl, dust cover and fender. On average, each car has 400-500 rubber parts, accounting for 4%-5% of the car's own quality. Therefore, as an upstream industry closely related to the automobile manufacturing industry, rubber products industry is also in the overall stage of vigorous development.

The production process of rubber products will produce a large number of carbon disulfide, non-methane total hydrocarbon and other organic waste gas, seriously affect the atmosphere. In recent years, all kinds of environmental pollution incidents have occurred, and the public has higher and higher requirements for environmental protection governance of enterprises involved in pollutant discharge and satisfaction with the surrounding environment. Complaints and relocation opinions about rubber odor and stench are common around rubber products enterprises. To this end, the Ministry of Environmental Protection jointly with the General Administration of Quality Supervision, Inspection and Quarantine of the State in October 2011 issued the GB27632-2011 "Rubber products industry pollutant discharge standard", the rubber products produced by the pollutants formulated strict emission standards. The standard has been implemented since January 1, 2012.

The exhaust gas produced by the rubber products industry is extremely complex and has nearly 100 kinds of pollutants discharged. In addition to the emissions of particulate matter, the domestic few of rubber products production process emissions of organic waste gas, a thorough investigation result in rubber products production enterprises in the stage of environmental impact assessment on the exhaust gas source strong calculation lack of theory and actual basis, to the local environmental protection administrative department of the follow-up to the rubber products enterprise environmental monitoring has brought a series of problems.

This paper mainly introduces the rubber manufacturers association (RMA) for tire rubber products production process of all kinds of rubber raw materials or components for testing of all kinds of waste gas pollutants discharge coefficient, and connecting with the domestic standards to analyze its applicability, in order to eia institution in calculating pollution sources and provide a reference basis to take necessary measures to prevent and control aspect, At the same time, it also provides relevant technical support for the daily approval and supervision of environmental management departments.

1 Test Object

RMA test rubber products are divided into 31 categories. Products are classified by rubber varieties and tires by main components, as shown in Table 1. Test materials commonly used include: Natural rubber (NR), brominated butyl rubber (BIIR), butadiene rubber (BR), styrene butadiene rubber (SBR), butyl rubber (IIR), ethylene propylene diene diene rubber (EPDM), chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), fluorine rubber (FKM), ethylene methyl acrylate rubber (AEM), hydrogenated nitrile rubber (HN) BR), silicone rubber (MVQ), acrylic rubber (ACM), chlorinated polyethylene rubber (CM), chloroether rubber (ECO) and polyvinyl chloride (PVC).

The 31 categories of rubber products basically cover the production of raw materials of rubber enterprises in the United States, compared with domestic rubber products enterprises, the overall difference is not obvious; The difference is that domestic rubber enterprises will use more recycled rubber to replace part of rubber, in order to reduce production costs.

Test the production process

Rubber products production processes mainly include mixing, extrusion, calendering, vulcanization and trimming grinding. Vulcanization can be subdivided into plate vulcanization, vulcanization tank, hot press vulcanization and tire vulcanization. In addition, tire vulcanization was mainly tested for 4 different types of tires. The exhaust gas emitted by tire belt layer, tire body, retread tire and tire side glue or white tire side repair and grinding were tested. RMA tests a total of nine rubber processing processes, corresponding to the test rubber or tire parts.

3 Test Results

The emission coefficient in the test results is expressed by the quality of pollutants discharged by the consumed rubber raw materials. The US Environmental Protection Agency adopts the British system for the emission coefficient. In this paper, it is uniformly converted into MG ˙ kG-1 according to general and domestic practices.

In addition, due to the various production processes of testing as many as dozens of varieties of pollutants, so according to the current domestic standard requirement to the necessary selection of pollutant, focusing on volatile organic compounds (VOCs), particulate matter, the methane total hydrocarbon, heavy metals harmful waste gas pollutants (HAP) and carbon disulfide in the statistics.

The emission coefficient of particulate matter in mixing and trimming process is large, while the emission coefficient of particulate matter in extrusion process is relatively small, which can be almost ignored. HAP emission coefficients of heavy metals in mixing and extrusion processes are small, while HAP emission coefficients of heavy metals in trimming and grinding processes are large. VOCs as rubber products manufacturing enterprises around the main source of odor and odor phenomenon, exist in the whole rubber products production process, in the calendering and extrusion process VOCs emission coefficient is relatively small, and vulcanization, hot roll plastizing, mixing and trimming grinding process VOCs emission coefficient is very large; The emission coefficients of non-methane hydrocarbons in calendering, extrusion and hot roll plasticizing processes are small, while those in mixing, vulcanization and trimming and grinding processes are relatively large. Calendering, extrusion, hot roll and tire sulfur chemical process in the carbon disulfide emission coefficient is relatively small, vulcanization, mixing and trim grinding process is affected by different test objects, carbon disulfide emission coefficient difference is more obvious, different rubber or tire components between the emission coefficient of several orders of magnitude.

In general, the mixing, vulcanization and trimming and grinding processes in the production process of rubber products industry are the key pollution production links, and the main pollutants discharged are VOCs, non-methane total hydrocarbon and particulate matter, which should be analyzed universally. The carbon disulfide emission coefficient of different processes and raw materials varies greatly, so it should be analyzed according to the actual raw materials. The overall emission coefficient of HAP heavy metals is small, which can be identified and analyzed according to specific procedures.

In addition, in the aspect of pollution prevention and control, we should control the whole process of VOCs generated in the production process of rubber products industry, improve the collection and treatment efficiency of waste gas through effective gas collection treatment facilities, and reduce the influence of odor and stench of VOCs emissions on the surrounding environment.

4 conclusion

(1) Rubber products in the production process of VOCs emission coefficient is very large, is the main source of odor and odor phenomenon in the surrounding environment, should carry out the whole process prevention and control, by improving the collection and processing efficiency, reduce the impact of VOCs emission odor and odor on the surrounding environment; At the same time, VOCs should be taken as the characteristic pollution factors of rubber products industry into the total control category.

(2) In the production of rubber products, mixing, vulcanization and trimming and grinding processes are the main pollution production links, which should be focused on prevention and control, and the main pollutants emitted by VOCs, total non-methane hydrocarbons and particulate matter should be universal analysis; Carbon disulfide and HAP heavy metals can be identified according to different raw materials or specific processes.