Environmental Protection in Tar Processing

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8.1 Basis for design: Environmental Protection Law of the People’s Republic of China (December 1989); Law of the People’s Republic of China on the Prevention and Control of Air Pollution (April 2000); Law of the People’s Republic of China on the Prevention and Control of Water Pollution (May 1996); Law of the People’s Republic of China on the Prevention and Control of Environmental Pollution by Solid Wastes (April 1996); Law of the People’s Republic of China on the Prevention and Control of Noise Pollution (October 1996); Law of the People’s Republic of China on the Promotion of Cleaner Production (October 2002); Technical Policy on the Prevention and Control of Hazardous Waste Pollution; Decree No. 253 of the State Council of the People’s Republic of China; Regulations on the Environmental Protection Management of Construction Projects; Technical Guidelines for Cleaner Production Levels in Key Industries (First Batch), issued by the Ministry of Economics and Trade [2000] No. 137. 8.2 Environmental quality standards and emission standards to be applied: 8.2.1 Environmental quality standards: For the atmospheric environment, the second-level standards specified in the Ambient Air Quality Standards (GB3095-1996) shall be applied. b. Surface water shall comply with the water quality standard for Class VI as specified in GB3838-2002, \"Environmental Quality Standards for Surface Water\" (GB3838-2002). The acoustic environment shall comply with Class II standards specified in Article c of the \"Standards for Environmental Noise in Urban Areas\" (GB3096-93). d. Groundwater shall comply with the secondary discharge standards specified in the \"Groundwater Quality Standards\" (GB/T14848-1993). 8.2.2 Pollutant emission standards a. For atmospheric emissions, the secondary emission standards specified in the Comprehensive Emission Standards for Air Pollutants (GB16297-1996) shall be applied. b. Wastewater discharge shall comply with the secondary discharge standards specified in the Comprehensive Wastewater Discharge Standards (GB8978-96). c. Noise control shall comply with Class II standards specified in the \"Standards for Noise at the Boundaries of Industrial Enterprises\" (GB12348-90). 8.3 Analysis of major pollution sources (1) Exhaust gases: a. The exhaust gases generated by burning coke oven gas in tar distillation tubular furnaces, industrial naphthalene primary distillation and rectification tubular furnaces, and asphalt vacuum distillation heating furnaces; the main pollutants emitted include SO2, NOx, etc ； b. Industrial waste gas extracted from the asphalt vacuum distillation tower ； c. The asphalt fumes emitted by the asphalt curing system have BaP as the main pollutant ； d. Naphthalene dust emitted from industrial naphthalene drum crystallizers ； e. The harmful gases emitted by the vent pipes, oil-water separators, coolers, and other equipment of various tank-type devices; the main pollutants are aromatics (hydrocarbons represented by benzene) and phenols, etc. (2) Wastewater: Tar processing wastewater mainly consists of high-concentration phenol-containing wastewater (primarily water from tar separation and wastewater resulting from the decomposition of sodium phenolate) ； Other phenol-containing wastewater includes floor washing water, wastewater from steam cleaning of pipes, and initial rainwater, etc ； As well as producing net wastewater (indirect cooling water) and domestic sewage, etc. (3) Solid waste: No solid waste is generated during tar processing; only tar residues are produced during raw material pretreatment and the cleaning of tar tanks. (4) Noise: The main sources of noise are various pumps and crystallizers. 8.4 Control Measures (1) Waste gas control measures: The gas used in the tar distillation tubular furnaces, the industrial naphthalene initial distillation and rectification tubular furnaces, and the asphalt vacuum distillation heating furnaces is intended to be entirely coke oven gas from Weifang Zhenxing Coking Plant, with a hydrogen sulfide content in the mixture of ≤20 mg/Nm3. The asphalt fumes emitted by the asphalt system are sent to an exhaust scrubber, where they undergo three stages of cleaning using circulating washing oil and water before being released after meeting the required standards. The naphthalene dust emitted by the industrial naphthalene drum crystallizer is removed by a bag filter, ensuring that the emissions meet the required standards. The industrial waste gas extracted from the asphalt vacuum distillation tower is pumped to a tar distillation tubular furnace for incineration. The oil-containing waste gas emitted by various devices and equipment is collected and washed with cleaning oil and water before being discharged in compliance with standards. (2) Wastewater treatment measures: The high-concentration phenol-containing wastewater generated during the tar processing is degreased using an oil-water separator, and then sent to the plant’s wastewater treatment facility at Weifang Zhenxing Coking Company for biochemical treatment. After meeting the secondary discharge standards specified in the **“Integrated Wastewater Discharge Standards” (GB8978-1996)**, the wastewater is discharged. The sodium carbonate wastewater generated in the fraction washing and carbonic acid decomposition sections is sent via pipelines to the ammonia steaming section of Weifang Zhenxing Coking Plant for ammonia steaming treatment, before being sent to the biological treatment section. Water used for flushing the floor, wastewater generated after steam cleaning during maintenance, and initial rainwater that may contain oil are first collected in oil-containing drainage pits. The oil is removed there using oil separators, and the water is then pumped into phenol tanks for collection. Finally, it is transported regularly by phenol pumps to the wastewater treatment unit at Weifang Zhenxing Coking Plant, where it undergoes biochemical treatment before being discharged into the municipal sewer system in compliance with environmental standards. · Other basically pollution-free wastewater, such as purified process wastewater, rainwater from later stages, and domestic sewage, is combined and then discharged into the drainage network. (3) Solid waste management measures: During the maintenance and cleaning of tar tanks in the tar processing process, as well as in the raw material preprocessing section, the tar residues generated are regularly transported by specialized cleaning teams to Weifang Zhenxing Coking Plant’s coal preparation system, where they are mixed into coking coal for use in coking processes. (4) Noise control measures: When selecting equipment, prefer pumps with low noise levels; for pumps that generate significant noise, install soundproof enclosures or silencers. Pump equipment should be installed indoors as much as possible to minimize the impact of noise on the outside environment. 8.5 Greening design of the factory area: It plays a role in beautifying the environment and improving the microclimate. The greening design for this project takes into account the specific characteristics of the project; grass planting is carried out in the reserved spaces within the planned construction area as well as along the roadsides, with the greening ratio accounting for over 30% of the total land area of the plant. 8.6 Environmental Management and Monitoring Agencies: The environmental monitoring and protection activities for this project are carried out by the environmental monitoring stations and environmental management staff specifically assigned for the project. 8.7 Analysis of the effectiveness of environmental protection measures for this project: The environmental protection measures adopted in this project are comprehensive, making use of mature technologies developed through years of practice both domestically and internationally. It represents one of the more advanced coal tar processing projects in the country, and its construction is in line with the industrial policies aimed at promoting centralized processing of coal tar. Large-scale centralized processing of coal tar not only improves the yield and quality of the products derived from tar, enabling better utilization of tar resources, but it also **reduces environmental pollution compared to small-scale tar processing units, thus truly achieving a balance between economic and environmental benefits. The environmental protection technologies used in this project are mature and reliable; the process exhaust gases are treated using effective methods such as incineration, dust removal, washing, and absorption ； After oil removal, the wastewater is sent to the biological treatment unit; it is discharged only after meeting the required standards ； Noise control technologies and waste treatment technologies are practical, effective, and cost-effective ； The vast majority of waste residues have been fully utilized, and greening measures as well as environmental monitoring methods have been basically implemented, enabling effective control of various pollutants such as air pollutants, water pollutants, residue, and noise. Greening can purify the air, absorb harmful substances, reduce noise, and protect the environment; it can also beautify the surroundings and improve the microclimate. The greening design for this project takes into account the specific characteristics of the project; grass planting is carried out in the reserved spaces within the planned construction area as well as along the roadsides, with the greening ratio accounting for over 30% of the total land area of the plant. 8.6 Environmental Management and Monitoring Agencies: The environmental monitoring and protection activities for this project are carried out by the environmental monitoring stations and environmental management staff specifically assigned for the project. 8.7 Analysis of the effectiveness of environmental protection measures for this project: The environmental protection measures adopted in this project are comprehensive, making use of mature technologies developed through years of practice both domestically and internationally. It represents one of the more advanced coal tar processing projects in the country, and its construction is in line with the industrial policies aimed at promoting centralized processing of coal tar. Large-scale centralized processing of coal tar not only improves the yield and quality of the products derived from tar, enabling better utilization of tar resources, but it also **reduces environmental pollution compared to small-scale tar processing units, thus truly achieving a balance between economic and environmental benefits. The environmental protection technologies used in this project are mature and reliable; the process exhaust gases are treated using effective methods such as incineration, dust removal, washing, and absorption ； After oil removal, the wastewater is sent to the biological treatment unit; it is discharged only after meeting the required standards ； Noise control technologies and waste treatment technologies are practical, effective, and cost-effective ； The vast majority of waste residues have been fully utilized, and greening measures as well as environmental monitoring methods have been basically implemented, enabling effective control of various pollutants such as air pollutants, water pollutants, residue, and noise. This post was last edited by ryn on 2009-2-27 15:56]