Environmental impact assessment approved for Ordos Xinnai Energy Chemical’s new 600,000 tons/year acetic acid production project

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Environmental impact assessment approved for Ordos Xinnai Energy Chemical’s new 600,000 tons/year acetic acid project. Author/Source: Date: 2018-08-09. Clicks: 114. Recently, the environmental impact assessment for Ordos Xinnai Energy Chemical Co., Ltd.’s 600,000 tons/year acetic acid project was approved and made public. The project is located in the Economic Development Zone of Dalaat Banner, Inner Mongolia, covering an area of 13.33 hm2. This project utilizes low-pressure methanol carbonylation technology to synthesize acetic acid from methanol as the raw material. The construction scale is an annual production of 600,000 tons of acetic acid. The main construction components of the project include the core processes such as synthesis, distillation, propionic acid production, absorption, and CO recovery, along with supporting utility systems, storage and transportation facilities, and environmental protection measures. The total investment for the project is 1,160.34 million yuan, of which 7.7 million yuan is allocated to environmental protection measures, accounting for 0.66% of the total investment. The chemical new materials project planned by Ordos Xinnai Energy Chemical Co., Ltd. will have an annual production capacity of 600,000 tons of acetic acid in the first phase, and 400,000 tons of ethyl acetate along with 450,000 tons of vinyl acetate in the second phase. The total investment in the project is 6.8 billion yuan; upon reaching full production capacity, it will be able to generate annual sales revenue of 5 billion yuan and a total profit of 2.5 billion yuan. Main environmental impacts and strategies and measures to prevent or mitigate adverse environmental impacts 1. Measures for air pollution control and main environmental impacts (1) Organized waste gases. The organized emission of waste gases mainly includes the CO2 off-gas from the CO purification unit, the waste gases from the low-pressure absorption tower, and the exhaust gases from PSA units. The main components of these gases are CO, CO2, H2, methane, N2, etc. They are discharged through pipelines for combustion in torches; after combustion, the concentration and emission rate of NOx in the exhaust gases meet the emission limit requirements specified in Table 4 of the \"Emission Standards for Pollutants in the Petrochemical Industry\" (GB31571-2015). (2) Unorganized emissions: During the operation of the facility, the finished acetic acid and propionic acid are loaded onto tank trucks for sale. A top-sealed cap-type submerged loading method is used, with a vapor recovery system that employs condensation and activated carbon adsorption to treat the acid mist generated during loading; as a result, no unorganized emissions occur. The removal efficiency for acetic acid and propionic acid is 99%, and the emissions of these substances in the treated waste gas are 0.079 t/a and 0.0027 t/a respectively. 2. Water pollution control measures and major environmental impacts (1) Production wastewater: The circulating water system of the project discharges 18 m3/h, the desalinated water system discharges 1 m3/h, and the compressed wastewater from the CO purification process discharges 0.9 m3/h; all of this wastewater is sent to the intermediate water treatment system at the industrial park’s sewage treatment plant. (2) Domestic wastewater: After being treated in septic tanks, domestic wastewater is discharged into the biochemical treatment system of the park’s wastewater treatment plant. 3. Solid waste prevention and control measures and major environmental impacts: During the operation period of this project, solid wastes include general solid wastes and hazardous wastes. The waste adsorbent from PSA units, at 20 tons per 5 years, the waste adsorbent from PSA adsorption towers, at 60 tons per 5 years, and the waste molecular sieve from nitrogen production units, at 0.3 tons per 5 years, all fall under the category of general solid waste, which is collected and processed by the manufacturers ； The 100 t/2 years of spent activated carbon from the desulfurization adsorption tower, and the 100 m3/2 years of spent catalyst from the hydrolysis tower, fall under HW49 – other wastes and HW50 – spent catalysts respectively in the **List of Hazardous Wastes**; they are disposed of by qualified entities. 16.7 tons of household waste per year are collected and disposed of uniformly by the sanitation department. The project designs a temporary storage site for general solid waste, located on the east side of the acetic acid plant area. It covers an area of 300 m2, and its construction meets the requirements of the \"Pollution Control Standards for Storage and Disposal Sites of General Industrial Solid Waste\" (GB18599-2001). A temporary storage facility for hazardous waste is to be established on the east side of the acetic acid plant area, adjacent to the temporary storage site for general solid waste. The facility will cover an area of 100 m2, and the hazardous waste within it will be stored in designated areas according to specific categories. Its construction will meet the requirements set out in the \"Standards for Pollution Control of Hazardous Waste Storage\" (GB18597-2001) and its amendments. The main sources of noise in this project are various power equipment such as pumps used in the production facilities. In accordance with the noise pollution control measures outlined in the Report, by optimizing the layout of the plant site, using high-quality, low-noise equipment, applying measures such as base shock absorption and sound insulation to various pump systems, and establishing dedicated pump rooms, the noise level at the plant’s boundary can meet the requirements of Class 3 standards specified in the \"Emission Standards for Environmental Noise at the Boundaries of Industrial Enterprises\" (GB12348-2008). The hazardous substances primarily involved in this project include methanol, CO, and the products such as acetic acid and propionic acid. Based on the identification of major risk sources, both the acetic acid product storage area and the raw material methanol storage area in this project are considered major hazard sources. In accordance with the risk prevention measures proposed in the Report, this project puts forward effective risk prevention measures in aspects such as the storage and transportation of hazardous chemicals, technical operations, safety control of accident-related wastewater discharge, and project management, and formulates emergency response plans. This project includes an accident pond with an effective volume of 2500 m3 and a preliminary rainwater pond of 60 m3, which can meet the project’s requirements.