Environmental protection in the coal chemical industry should focus on VOCs control

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Achieving environmentally compliant emissions is a task that the coal chemical industry must accomplish. Complying strictly with environmental protection requirements throughout the entire process of coal chemical project design, construction, commissioning, and operation, as well as passing acceptance inspections and undergoing regular supervision, represent the real challenges faced by operators of such projects. In the actual operation of coal chemical enterprises, the odors, or even foul smells, emitted represent an important factor affecting the relationship between these enterprises and local residents. When sulfur recovery units are operating properly, such odors are mainly caused by the emission of volatile organic compounds (VOCS). In December 2014, the Ministry of Environmental Protection issued the \"Comprehensive Plan for the Control of Volatile Organic Compounds in the Petrochemical Industry\" (hereinafter referred to as the \"Plan\"), requiring other chemical-related enterprises such as those in the coal chemical industry to carry out their work in accordance with the relevant requirements set out in this Plan. The Plan requires comprehensive efforts to address VOCs issues in the petrochemical industry, to significantly reduce VOCs emissions from this sector, and to improve environmental air quality. Strictly control emissions from process exhaust gases, leaks at the sealing points of production equipment, volatilization losses during storage and handling processes, emissions from wastewater, waste liquids, and waste residue systems, as well as pollution discharge under abnormal operating conditions. VOC emissions are reduced at the source through measures such as implementing process improvements, enhancing the sealing of production processes as well as wastewater, waste liquid, and waste residue systems, carrying out Leak Detection and Repair (LDAR) on equipment, and improving tank designs and loading/unloading methods ； Recycle process exhaust gases, tank vent gases, and loading/unloading exhaust gases that have value for recovery ； Waste gas that is difficult to recycle is treated in accordance with relevant requirements. By 2017, the petrochemical industry across the country had essentially completed the comprehensive control of VOCs; a monitoring system for VOCs was established, and the total amount of VOCs emitted was reduced by more than 30% compared to 2014. The Plan proposes to enforce strict environmental access controls for construction projects. Environmental protection authorities at all levels optimize and adjust the layout of the petrochemical industry in line with requirements such as the main functional zone planning, environmental functional zone planning, and urban master plans. Strengthen the guidance and constraints of industrial policies to accelerate the phasing out of outdated products, technologies, and process equipment. New, modified, and expanded petrochemical projects should adopt advanced clean production and closed-system processes during design and construction, raise design standards, and ensure that equipment, installations, pipelines, and sampling systems are enclosed in order to reduce VOC emissions at the source. Efficient measures for the recovery and treatment of organic vapors should be implemented in processes related to storage, loading and unloading, as well as in the handling of wastewater, waste liquids, and waste residues, in order to meet national and local regulations regarding emission limits and environmental quality standards. Yahua Consulting believes that environmental protection measures for coal chemical projects should be planned in advance; comprehensive control of VOCs should be taken into account during the stages of environmental impact assessment, engineering design, and selection of processes and equipment. Only in this way can true environmental friendliness be achieved. For coal chemical projects that are already in operation, LDAR technology is the leak management technique widely used in developed countries today; its purpose is to control the uncontrolled emissions of VOCs. Qualitative and quantitative monitoring equipment is used to monitor areas in chemical plants where VOC leaks are likely to occur, such as various reaction vessels, raw material transfer pipelines, pumps, compressors, valves, flanges, etc. If the instrument readings exceed the leakage limits, repairs and re-inspections must be carried out within a specified time frame, so that leakage points can be detected and identified promptly, repaired quickly, and verified again after repair, thereby reducing raw material waste and VOC emissions. In November 2015, the Ministry of Environmental Protection accepted applications for four major coal chemical projects: 1. Inner Mongolia Yitai’s 2 million tons per year coal indirect liquefaction demonstration project; 2. Sinopec Great Wall Energy Chemicals (Guizhou) Co., Ltd.’s 600,000 tons per year polyolefin project; 3. the joint venture between China Power Investment and Total, aiming to produce 800,000 tons per year of coal-based polyolefins; 4. Suzhou New Energy & Feng Co., Ltd.’s project to produce 4 billion standard cubic meters per year of coal-based natural gas. Yahua Consulting believes that the environmental impact assessment approval results for these four major projects will hold significant exemplary value for the advancement of coal chemical projects in China.