VOCs mainly exist in raw materials or products of enterprises, most of which are flammable and explosive, and some are toxic and harmful substances. Strengthening VOCs control is an effective way to control air pollution at present, and it is also a powerful means to help enterprises save resources, improve efficiency, and reduce safety hazards.
At present, the country has made the reduction of total VOCs emissions a binding indicator for the ecological environment during the 14th Five Year Plan period. The Ministry of Ecology and Environment also requires a systematic review of the "13th Five Year Plan for the Prevention and Control of Volatile Organic Compounds Pollution", "Comprehensive Management Plan for Volatile Organic Compounds in Key Industries", "2020 Key Plan for the Control of Volatile Organic Compounds", and the VOCs control issues feedback from the supervision and assistance of the Ministry of Ecology and Environment for summer ozone pollution prevention and control in 2020.
At the same time, it is required that key areas for air pollution prevention and control (hereinafter referred to as key areas) organize enterprises to complete a round of investigation work by the end of October 2021, and other areas by the end of December 2021.
How should chemical companies choose to improve the scientific, targeted, and effective management of volatile organic compounds (VOCs) in related industries after self inspection?
Key points for prevention and control of VOCs related enterprises
The key points for controlling volatile organic compounds in the chemical industry are mainly applicable to industries such as petroleum, coal, and other fuel processing, chemical raw materials and chemical product manufacturing (chemical pesticides), pharmaceutical manufacturing (chemical drug raw materials), chemical fiber manufacturing (polyester, nylon), rubber, and plastic products.
In the raw material process, relevant chemical enterprises should investigate whether the VOCs content of the materials produced, sold, and used meets the national or local VOCs content limit standards.
The identification of VOCs materials is determined according to the "Control Standards for Unorganized Emissions of Volatile Organic Compounds"
At the same time, it is necessary to confirm whether the tank type and materials match and meet the operation and maintenance requirements;
② Whether the storage tanks and silos are completely enclosed;
③ Whether the container or packaging bag is sealed for use or storage;
④ Is the transfer process of VOCs related materials sealed;
⑤ Whether the material reprint meets the requirements
Unorganized emissions of VOCs
It should be noted that the biggest difference between unorganized emissions and organized emissions is that organized emissions mainly focus on whether the pollutant emission concentration at the discharge outlet meets the standard, while unorganized emissions mainly focus on whether the specific measures taken by enterprises in various links such as storage, transportation, production, and use meet the standard requirements.
Therefore, only by doing a good job in the comprehensive, full chain, and full link closed management of VOCs containing materials can unorganized emissions be effectively controlled. The key points in the relevant standards are as follows:
① The storage process of VOCs containing materials should use sealed containers, packaging bags, efficient sealed storage tanks, enclosed storage warehouses, silos, etc.
② The loading, unloading, transfer, and transportation of materials containing VOCs should be carried out using closed pipelines or containers, tank trucks, etc.
③ The production and use of materials containing VOCs should be carried out in enclosed spaces or effective collection measures such as negative pressure should be taken.
④ The disposal process should cover and seal the waste packaging containers that have contained VOCs materials, dispose of them properly according to requirements, and not discard them at will.
⑤ The collection, transportation, storage, and treatment of high VOC content wastewater (with VOCs detection concentration exceeding 200ppm at a height of 100mm above the wastewater surface, with key areas exceeding 100ppm, calculated as carbon) should be covered and sealed.
⑥ If the sealing points of equipment and pipeline components carrying gaseous or liquid VOCs materials in an enterprise are greater than or equal to 2000, leakage detection and repair (LDAR) work should be carried out in accordance with the requirements.
Organized emissions of VOCs
Organized emissions of VOCs require confirmation of whether treatment facilities have been installed and whether the emission concentration complies with the Comprehensive Emission Standards for Air Pollutants.
Many companies' VOCs treatment facilities are still at the level of "having or not having" and "not improving", thinking that having facilities is enough. There are generally problems such as incomplete management systems, lack of established operating procedures, insufficient personnel technical capabilities, and poor operational management.
The design and installation of pollution control facilities are generally not standardized, and the collection rate is low; Lack of effective monitoring methods and low equipment operation rate; The market is flooded with inefficient process facilities, and the problem of low processing rates and low "three rates" has become a clear weakness.
*Common VOCs End of pipe Treatment Technologies in Technical Guidelines
In relevant research, from the perspective of regions and cities, the proportion of enterprises with environmental problems in the Pearl River Delta, Yangtze River Delta, and middle reaches of the Yangtze River is relatively high. Among them, the proportion of problematic enterprises in the oil and gas storage industry is as high as 74%, the proportion of chemical enterprises with problems is 50%, and the proportion of petrochemical enterprises is 42%.
Among the types of problems, 32% are related to organized emissions of VOCs, 25% are related to unorganized emissions of VOCs, and 20% are related to storage and transportation of VOCs materials.
In response to the above issues, the government needs to implement source control in addition to the VOCs content limit standards for products, forming a comprehensive VOCs pollution prevention and control environmental protection standard system. At the enterprise level, efforts still need to be made to improve the scientific, targeted, and effective governance, and promote the implementation of upgrading and transformation of enterprises through a model of promoting governance in accordance with the law and policy guidance.
Haipu can provide customized process design for VOCs waste gas emissions in enterprises, and cooperate with the development of HDV type polymer nano adsorbents to improve the management level of VOCs in enterprises.
In terms of processing principle, the relevant VOCs waste gas is first extracted by a vacuum pump and then subjected to secondary condensation. The condensed and liquefied components are received in a storage tank, and the uncondensed waste gas is connected to an adsorption tower containing nano adsorbents for adsorption and enrichment. After adsorption, the waste gas can meet the emission standards.
After the adsorbent is saturated with adsorption, it is blown off. The mixture of blown off components and water vapor is then condensed and liquefied, and allowed to stand and separate into layers for separation and recovery. This process can achieve a removal rate of over 98% for dichloroethane in waste gas, and is also suitable for the treatment of waste gases such as dichloromethane, toluene, and dibromopropane.
If an agricultural chemical enterprise adopts our technology, the overall design parameters are as follows.
This project adopts PLC program automatic control to monitor the temperature, pressure, liquid level and other parameters of the adsorption device in real time, achieving full automation operation. The PLC communicates with the upper computer, making it easy to grasp the operation of the device during production. The independent operation control cabinet equipped is also convenient for management and daily maintenance.
*On site VOCs treatment adsorption process project
Actively investigate and handle
In recent years, the emission standards for VOCs, as well as the content standards for VOCs products such as coatings, inks, adhesives, and cleaning agents, have been continuously improved.
In response to the prominent problems in the current VOCs governance and the VOCs emission reduction targets for the 14th Five Year Plan, relevant enterprises should carry out inspections and rectification of key production and manufacturing processes in accordance with the requirements of the "Notice on Accelerating the Resolution of Prominent Issues in VOCs Governance" issued by the Ministry of Ecology and Environment, and promptly deal with any problems found.
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