Core Viewpoint - The article highlights Nanjing's innovative approach to managing volatile organic compounds (VOCs) emissions from storage tanks, showcasing a successful model for air quality improvement that can be replicated nationwide [1][3]. Group 1: Background and Context - Nanjing, as a significant petrochemical industry base in East China, has a yearly turnover of 230 million tons of VOCs-related materials across 2,606 storage tanks owned by 129 companies, contributing to 30% of the city's VOCs emissions [2]. - VOCs are crucial precursors for ozone and PM2.5, making their management essential for air quality [2]. Group 2: Governance and Management Measures - In May 2023, Nanjing initiated a comprehensive inspection of its 2,606 storage tanks, implementing ten management measures focused on source control, component management, and leak detection [3]. - A digital registry was established for each storage tank, detailing type, material, structure, sealing level, and treatment facilities, transitioning from a manual oversight approach to a precise management system [3]. Group 3: Technological Innovations - The introduction of low-leakage breathing valves reduced emissions from 0.4 cubic meters per hour to 0.003 cubic meters per hour, significantly minimizing VOCs release [4]. - Upgrades included the implementation of full-contact floating roofs and high-efficiency sealing technologies, which virtually eliminated evaporation spaces [4]. - A direct heating feed monitoring system was developed to enhance operational efficiency, allowing over 80% of feed to be supplied directly, thus reducing VOC generation [4]. Group 4: Results and Impact - As of now, Nanjing has completed modifications on 450 storage tanks and replaced 1,900 low-leakage breathing and emergency pressure relief valves, achieving substantial improvements in VOC management [5]. - The deep governance of storage tanks is projected to reduce VOC emissions by 7,400 tons annually, saving companies over 50 million yuan in material costs each year [5]. - VOCs concentration in the Jiangbei New Materials Science and Technology Park is expected to drop from 6.9 ppb in 2023 to 1.8 ppb by 2025, a reduction of 74%, improving the park's ranking among chemical parks in the province [6]. - Since the 14th Five-Year Plan, Nanjing has seen a notable decline in ozone pollution, with the number of days exceeding ozone standards decreasing by six days by 2025 [6].

Core Viewpoint - The article highlights Nanjing's innovative approach to managing volatile organic compounds (VOCs) emissions from storage tanks, showcasing a model that can be replicated nationwide for effective air quality improvement [1][3]. Group 1: VOCs Emission Management - Nanjing, a significant petrochemical hub in East China, has a yearly turnover of 230 million tons of materials in VOCs storage tanks, contributing to 30% of the city's VOCs emissions [2][3]. - The city initiated a comprehensive inspection of 2,606 storage tanks to enhance management and reduce emissions, starting with a notification issued in May 2023 [3][4]. Group 2: Technological Innovations - The introduction of low-leakage breathing valves has significantly reduced emissions, with leakage rates dropping from 0.4 cubic meters per hour to 0.003 cubic meters per hour [4]. - Upgrades to storage tank designs, such as full-contact liquid floating roofs, have minimized evaporation losses, while advanced sealing technologies have further reduced leakage [4][5]. Group 3: Results and Impact - As of now, Nanjing has completed modifications on 450 storage tanks and replaced 1,900 low-leakage breathing and emergency pressure relief valves, leading to an annual reduction of 7,400 tons of VOCs emissions and saving over 50 million yuan in material costs for enterprises [5][6]. - The concentration of VOCs in the Jiangbei New Materials Science Park has decreased from 6.9 parts per billion (ppb) in 2023 to 1.8 ppb by 2025, marking a 74% reduction and improving the park's ranking among chemical parks in the province [5][6].

Core Viewpoint - The article highlights the potential environmental risks associated with volatile organic compound (VOC) storage tanks, emphasizing the need for proactive measures to prevent leaks and improve air quality [1][2]. Group 1: Risk Identification and Prevention - There are instances of weak irritating odors near large VOC storage tanks, indicating possible minor leaks that could collectively harm air quality [1] - Companies should enhance training to raise awareness of leak risks, using case studies and data comparisons to illustrate the ecological impacts of tank leaks [1] - A "one tank, one policy" approach is recommended, where expert teams assist companies in developing tailored risk assessment and mitigation plans based on specific tank types and VOC categories [1] Group 2: Technical Support and Equipment Upgrades - Practical techniques for leak detection, repair, and emergency response should be taught on-site to improve companies' preventive measures [1] - Valve leaks are identified as a common ecological risk, and the adoption of low-leak breathing valves and emergency pressure relief valves is encouraged to mitigate these risks [1] - Local authorities should assist companies in understanding the selection standards, installation guidelines, and maintenance points for low-leak valves to achieve emission reduction and efficiency improvements [1] Group 3: Management Mechanism - Establishing a closed-loop management mechanism that includes training, inspection, rectification, and re-inspection can enhance companies' responsibility for pollution prevention [2]