Pre-approval for the environmental impact assessment of Sinopec’s Guizhou coal chemical project, with an investment of 23.8 billion yuan

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Public announcement of the approval opinions on the environmental impact assessment documents (reports and forms) for construction projects to be issued by the Guizhou Provincial Department of Ecology and Environment on March 15, 2021 (Sinopec Great Wall Energy Chemical (Guizhou) Co., Ltd.’s 500,000 tons/year polylactic acid (PGA) project). The public display period is from March 15, 2021, to March 19, 2021 (5 working days). Project Name: Sinopec Great Wall Energy Chemical (Guizhou) Co., Ltd.’s 500,000-ton/year Polyglycolic Acid (PGA) Production Project
Location: Zijin New Energy and Chemical Industry Base, Bijie City, Guizhou Province (the plant is located in Moda Village, Chadian Township)
Project Owner: Sinopec Great Wall Energy Chemical (Guizhou) Co., Ltd.
Name of the entity responsible for preparing the environmental impact assessment report: Guizhou University Science and Technology Park Development Co., Ltd.
Project Overview: The 500,000-ton/year Polyglycolic Acid (PGA) production project owned by Sinopec Great Wall Energy Chemical (Guizhou) Co., Ltd. is located within the Zijin New Energy and Chemical Industry Base in Bijie City, Guizhou Province (with the plant situated in Moda Village, Chadian Township). The total land area required for the project is approximately 426.66 hectares. The project will be constructed in two phases: the first phase, involving a 200,000-ton/year PGA production facility, is scheduled to be completed in 2024, while the second phase, with a 300,000-ton/year PGA production facility, is expected to be completed in 2026. The project uses coal, methanol, nitric acid, limestone, and other materials as primary raw materials to produce polyglycolic acid (PGA). By-products include methyl formate, dimethyl oxalate, crude ethylene glycol, mixed alcohols, acid-containing mixed alcohols, polyols, oligomers, etc., all of which can be sold as commercial products. Once the project is completed and put into operation, the production units and key auxiliary production facilities will operate on a continuous basis, following a 4-shift, 2-shift system, with 333 days of operation per year and 8,000 hours of working time annually. The planned workforce for the first phase of the plant is 570 people, while that for the second phase is 200 people; the total planned workforce for both phases combined is 770 people. The total investment for the project is 2,376,767 million yuan, of which 1,233,160 million yuan is invested in Phase 1 and 1,143,607 million yuan in Phase 2. The environmental protection investment for Phase 1 was 681.16 million yuan, accounting for 5.52% of the total investment in that phase; the environmental protection investment for Phase 2 was 185.9 million yuan, representing 1.62% of the investment in that phase. Main environmental impacts and environmental protection countermeasures 1. Measures for air pollution control (1) Measures for controlling dust-containing waste gas The raw coal and fuel coal used in this project are stored in one circular storage yard each (shared by phases 1 and 2). By adjusting the height of the stacked materials, the drop distance of the material is reduced. An explosion-proof bag filter is installed at the raw coal storage yard, and another explosion-proof bag filter is installed at the fuel coal storage yard ； An explosion-proof bag filter is installed in the raw coal blending silo (shared by Phase I and Phase II) ； Explosion-proof bag filters are installed in the raw coal crushing building and the fuel coal crushing building (shared by phases 1 and 2) ； Bag filter supporting the coal transfer station at the plant site (shared by Phase I and Phase II) ； Bag filter for the raw coal silo in Phase 2 of the project ； Bag filter for the limestone powder silo in Phase 2 of the project. The above dust-containing waste gas, after treatment, meets the standards specified in Table 4 of GB31572-2015 \"Emission Standards for Pollutants in the Synthetic Resin Industry\". (2) Waste gas from the coal gasification unit: The heat source for drying coal powder comes from the hot air generated by the hot air furnace, which uses low-nitrogen combustion; the dried waste gas is filtered through a bag filter before being discharged ； A high-efficiency long-bag low-pressure pulse-jet bag filter is installed for treating the exhaust gases discharged from the gasification furnace ； The start-up gas generated during the startup of the gasifier is burned through the plant’s flare system before being released into the atmosphere. The waste gas from the gasification unit, after treatment, meets the standard limits specified in Table 4 (Process Heating Furnaces) of GB31571-2015 \"Emission Standards for Pollutants in the Petrochemical Industry\". (3) The tail gas from the wash tower discharged from the low-temperature methanol washing unit mainly consists of CO2 and nitrogen; desalinated water is used to wash and absorb any residual trace amounts of methanol, and the washed gas is then released through an exhaust stack. Methanol is subject to GB31571-2015 \"Emission Standards for Pollutants in the Petrochemical Industry\", while hydrogen sulfide is subject to DB52/864-2013 \"Emission Standards for Environmental Pollutants in Guizhou Province\". (4) The acidic gases emitted from the low-temperature methanol washing unit in the gas purification section contain H2S. This project includes a sulfur recovery unit to treat these acidic gases, converting the sulfur-containing components in the waste gas into sulfur products. The treated exhaust gas is then sent to an incinerator for combustion, and the combustion exhaust gas is desulfurized using alkaline washing to meet the requirements of GB31571-2015 \"Emission Standards for Pollutants in the Petrochemical Industry\". (5) Waste gas from the coupling hydrogenation unit: The oxygen-containing waste gas from the esterification section of Phase 2, as well as the non-condensable gas from the MG purification unit, are both fed into the same waste gas treatment facility for incineration ； The PSA purge gas from the MG hydrogenation unit and the waste gas from the hydrogenation intermediate product tanks in both phases are fed into the plant’s gas pipeline network ； The waste gas from the MG refined exhaust gas absorption tower mainly contains water-soluble substances such as acetic acid, methyl glycolate, methanol, and VOCs. Desalinated water is used for absorption; most of these substances are sent to the plant’s wastewater treatment facility for processing. The unabsorbed substances, including methanol and VOCs (expressed as total non-methane hydrocarbons), are discharged through the exhaust stack after meeting the requirements specified in GB31571-2015 \"Emission Standards for Pollutants in the Petrochemical Industry\". (6) For the exhaust gas from PGA devices, the PGA synthesis exhaust gas absorption tower emits gases that mainly contain water-soluble substances such as VOCs and methanol. Desalinated water is used for absorption; most of these substances are sent to the plant’s wastewater treatment facility for processing. The unabsorbed substances, including methanol and VOCs, meet the limits specified in Table 4 of GB31571-2015 \"Emission Standards for Pollutants in the Petrochemical Industry\", and are thus discharged through the exhaust stack ； The exhaust gases generated during pellet drying contain mainly VOCs; after being absorbed by deionized water in the absorption tower, they meet the requirements specified in Table 4 of GB31571-2015 \"Emission Standards for Pollutants in the Petrochemical Industry\" and are then released through the exhaust stack ； The exhaust gas from the lactide pneumatic conveying system mainly contains particulate matter; after being removed by a bag filter, it meets the requirements of GB31572-2015 \"Emission Standards for Pollutants in the Synthetic Resin Industry\" and is then discharged through an exhaust stack ； The exhaust gas from the PGA product pneumatic conveying system mainly contains particulates; after being removed by a bag filter, it meets the requirements of GB31572-2015 \"Emission Standards for Pollutants in the Synthetic Resin Industry\" and is then discharged through the exhaust stack ； The heat transfer oil furnace in the PGA unit uses purified gas from the plant’s gas pipeline network as fuel. The exhaust gases generated by this furnace mainly consist of particulate matter and nitrogen oxides. The furnace employs low-nitrogen combustion, and the exhaust gases meet the standard limits specified in Table 2 of GB13271-2014 \"Emission Standards for Air Pollutants from Boilers\", and are discharged through exhaust stacks. (7) Exhaust gases from the tank area: Different tank structures are selected based on the storage period and quantity of liquid materials. Internal floating roof tanks are used for liquids that are stored for long periods and in large quantities, while dome-shaped tanks are used for those that are stored for short periods and in smaller quantities. In addition, all liquid storage tanks are equipped with nitrogen sealing ； The VOCs generated during the loading and unloading of liquid materials in the tank farm are collected and then sent to a VOCs treatment unit, where they are treated using a \"condensation adsorption + washing\" process to meet the requirements of GB31571-2015 \"Emission Standards for Pollutants in the Petrochemical Industry\". (8) The circulating fluidized bed boiler in the project’s power station utilizes a combination of \"desulfurization inside the furnace + low-nitrogen combustion + SNCR + SCR + electrostatic dust removal + external LJD dry desulfurization + bag dust removal\". Ultra-low emission standards are applied for particulate matter, SO2, and NOX, while the standards specified in GB13223-2011 \"Emission Standards for Air Pollutants from Thermal Power Plants\" apply to mercury and its compounds. (9) The permanent light in the flare system uses purified gas from the plant’s gas pipeline network as fuel; the combustion exhaust gases mainly contain particulates, sulfur dioxide, and nitrogen oxides, which are discharged directly through the flare tip. (10) The waste gases burned in the plant’s waste gas incinerator are purified using the \"SCR denitration + alkaline washing + wet electrostatic precipitator\" system, so as to meet the emission standards specified in GB31571-2015 \"Emission Standards for Pollutants in the Petrochemical Industry\". (11) Each of the wastewater treatment plants for the two phases of the project is equipped with a box-type integrated biological deodorization unit utilizing a \"washing + biological filter\" treatment process. The odor concentration emissions meet the requirements specified in Table 2 of GB14554-93 \"Emission Standards for Odorous Pollutants\"; the emissions of NH3 and H2S comply with the standards set out in Table 4 of DB52/864-2013 \"Emission Standards for Environmental Pollutants in Guizhou Province\"; whereas the NMHC emissions meet the standards specified in Table 4 of GB31571-2015 \"Emission Standards for Pollutants in the Petrochemical Industry\". 2. Measures for preventing and controlling wastewater The plant area is equipped with a drainage system based on the principles of separating rainwater from sewage, separating clean water from polluted water, and treating water according to its different qualities. The wastewater from various units and devices is treated separately; wastewater that does not meet the standards set by the wastewater treatment plant is subjected to pre-treatment either within the device itself or through centralized pre-treatment, so that it meets those standards before being sent to the plant’s wastewater treatment plant for further treatment and reuse, without being discharged outside. Production wastewater series: Treats all the production wastewater and domestic wastewater generated by the plant, including salt-free production wastewater from various units, salt-containing production wastewater, wastewater from circulating cooling systems, and wastewater from chemical water treatment stations. The salt-free production wastewater is delivered via pressure pipes to the production wastewater homogenization tank, from where it flows by gravity to the dissolved air flotation unit for biochemical treatment ； The saline production wastewater is fed into the hardness, fluoride, and cyanide removal system via pressure pipelines; under the action of chemicals, most of the calcium and magnesium ions, fluoride ions, and CN- in the wastewater are removed, and sludge separation from water is achieved in the sedimentation tank. After neutralization, the water from the hard water and fluoride removal softening system is pumped to the saline wastewater homogenization tank, where it undergoes volume adjustment and quality mixing before being sent for biological treatment ； The wastewater from the circulating water system first enters the high-density sedimentation tank of the circulating water pretreatment system, where most of the calcium and magnesium ions as well as particulate matter are removed. The water exiting this tank is then mixed with wastewater that has been treated by the A/O system, and together they flow automatically to the ozone-catalyzed oxidation tank for producing wastewater. There, the biodegradably difficult large-molecule organic substances are broken down into more easily degradable substances. After that, the water proceeds to the ozone stabilization tank, where any unreacted ozone is released. The effluent flows naturally to the biological aerated filter for wastewater treatment, where the remaining COD in the water is further removed through the oxidation and adsorption actions of the biofilm attached to the surface of the packing material as well as the biological flocs between the packing elements. After that, it is reused in production following treatment via sand filtration and ultrafiltration. High-salinity water series: A series for treating wastewater generated by sewage treatment plants, involving ultrafiltration to produce reverse osmosis concentrate and wastewater from sulfur processing units. After pre-treatment, membrane concentration, nanofiltration for salt separation, evaporation, and crystallization, most of the water is recycled. The high-purity Na2SO4 and high-purity NaCl crystals formed through crystallization are utilized in various applications, while the small amount of residual liquid, after drying, is treated as hazardous waste and disposed of externally. 3. Measures for preventing groundwater pollution: Optimize the layout of the plant site by locating the main production facilities, sewage treatment systems, raw material storage systems, and other key equipment in areas with bedrock fracture water or karstic fracture water. Avoid entirely the areas where the Guanling Stage 2 strata with developed karst features (and associated karstic cave water) are found. Areas with karstic cave water should be used primarily as auxiliary production areas and areas in front of the plant, including areas for landscaping, offices, and residential use, in order to minimize the presence and accumulation of pollutants in such areas ； In accordance with the principle requirements of GB/T50934 \"Code for Seepage Control in Petrochemical Projects\", the proposed project has determined the pollution control zones within the plant area in a rational manner, and implemented comprehensive seepage control measures for each zone. Taking into account the process characteristics of the project and the hydrogeological conditions of the site, a range of seepage control measures—such as enhanced foundations (consolidation grouting), pollution isolation (clay or equivalent geotextiles), pollution containment (HDPE membranes), collection and drainage systems (non-woven geotextiles and gravel), and impermeable concrete flooring—have been applied in whole or in part to different seepage control zones, ensuring that the groundwater environment remains unpolluted under all operating conditions ； Establish a site-centered comprehensive prevention and control system for groundwater pollution. The construction of the comprehensive prevention and control system is based on the core principle of combining diversion with interception; it includes surface interception around the site, horizontal impermeabilization in the equipment area, as well as a range of targeted engineering measures such as advection diversion and hydraulic interception. 4. Noise pollution control measures: Where feasible, low-noise equipment should be selected, provided that the process design and technical requirements are met ； Control from the noise propagation path: Take measures such as sound absorption, sound insulation, and vibration reduction for the sound source. During design, attention should be paid to the characteristics of each noise-generating device; sound insulation of enclosures such as factory buildings should be fully utilized, and sound-insulating enclosures should be installed around devices that generate high sound pressure levels ； Silencers are installed on aerodynamic noise sources such as air compressors and fans, and vibration-damping foundations are used for various equipment that generates vibrations, in order to reduce the propagation of vibration noise. Through the above measures, it is ensured that the noise level at the project’s boundary meets the requirements of Class 3 as specified in GB12348-2008, the Standard for Emission of Environmental Noise at the Boundaries of Industrial Enterprises. 5. Measures for preventing and controlling solid waste pollution: General solid wastes such as coal gasification ash and slag, as well as boiler ash and slag from power stations, are collected centrally at designated slag disposal sites and then utilized in various applications such as building materials, the production of cementing materials, agricultural fertilizers, and soil conditioners ； When fly ash is used as an active admixture in cement and as a blending material in concrete, its quality must meet the requirements of the standard GB/T1596-2017 \"Fly Ash for Concrete and Cement\" ； The waste catalysts generated by each device are returned to the manufacturer for recycling ； The waste catalysts that are replaced on a regular basis usually contain heavy metals or involve patented technologies and trade secrets; when the manufacturer delivers new catalysts, the old catalysts are retrieved and the original manufacturer is responsible for their recycling ； The wastewater treatment for the proposed project will adopt a zero-discharge approach; after double-membrane desalination, the reverse osmosis concentrate is processed through \"membrane concentration + nanofiltration for salt separation + evaporation crystallization\" to enable the reuse of most of the water. Sodium sulfate and sodium chloride crystalline salts are produced as by-products, while the drying of the high-concentration recycled mother liquor yields a small amount of salt sludge (mixed salts) ； The crystalline pure salt of Na2SO4 can meet the qualified product standards of Class III specified in GB/T6009-2014 \"Industrial Anhydrous Sodium Sulfate\", while the crystalline pure salt of NaCl can meet the Grade 2 standards for sun-dried industrial salt as defined in GB/T5462-2015 \"Industrial Salts\"; both can be sold as chemical raw materials. Hazardous waste: Mixed salts, after being properly packaged to prevent leakage, are handed over to qualified entities for disposal ； Given that the fractional crystallization technology used in the \"zero wastewater discharge\" treatment schemes for the coal chemical industry has not yet been applied on a large industrial scale, the proposed project also considers alternative options regarding the disposal of the sodium sulfate and sodium chloride by-products produced through fractional crystallization; that is, if the quality of these crystallized salts does not meet the requirements for comprehensive utilization, they will be disposed of as hazardous waste ； Hazardous waste is collected according to specific categories and temporarily stored in the plant’s hazardous waste storage area. This storage area is designed in strict compliance with the requirements of GB18597-2001, the \"Pollution Control Standards for the Storage of Hazardous Waste.\" Its main purpose is to store temporarily small amounts of waste catalysts that are removed from various process units from time to time, as well as ammonia-containing methanol waste liquid generated by the low-temperature methanol washing unit. General industrial solid wastes that cannot be comprehensively utilized in the proposed project are sent to various slag dumping sites for landfill disposal. Mainly waste molecular sieves and waste perlite generated by air separation units ； Sludge from water purification plants, as well as certain gasification ash and boiler ash that do not meet the quality requirements for comprehensive use in construction materials. 6. Measures for preventing soil pollution: For construction projects that pose a risk of pollution to the soil, the focus of protective measures is on source control; the project owners must implement leak prevention measures within the facility to avoid any leaks. The factory area should implement separate systems for rainwater and wastewater to prevent surface water from flowing into the surrounding environment. Dredging ditches should be constructed around the factory, and an accident containment tank should be built at the lowest point of the facility. Source: Project QuickQuickQuick