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Carbon Emission Information Disclosure of Shaanxi Changqing Energy Chemical Co., Ltd. for 2020 Author/Source: Shaanxi Changqing Energy Chemical Co., Ltd. Date: 2021-05-18 Clicks: 8 The company’s first methanol production project, with an annual capacity of 600,000 tons, uses coal as raw material and employs a water-coal slurry gasification process to produce crude syngas. This crude syngas is desulfurized and decarburized through a sulfur-resistant, wide-temperature shift reaction process and a low-temperature methanol washing process; after compression, it is fed into the IMC methanol synthesis tower to produce crude methanol. The crude methanol is then refined through three distillation towers to yield pure methanol product. The auxiliary utility systems include power generation units, water systems, coal storage and transportation facilities, etc. The power generation units consist of three high-temperature and high-pressure coal powder boilers with a capacity of 180 t/h, operating at 9.8 MPa and 540°C, as well as two 12 MW regenerative waste heat recovery generators. The exhaust gases from these power generation units are treated using ammonia-based desulfurization, SCR denitrification, bag filtration, and wet electrostatic dust removal processes. In 2020, the company paid close attention to the daily operation, inspection, and maintenance of the environmental protection facilities related to its power generation systems. The emission levels were approximately 2 mg/m3 for dust, 13 mg/m3 for SO2, and 27 mg/m3 for NOx – figures that are lower than the emission limits specified in the DB61/1226-2018 standards for air pollutants from boilers in Shaanxi Province (Table 2), where the allowable emission levels are ≤50 mg/m3 for NOX, ≤10 mg/m3 for particulate matter, and ≤35 mg/m3 for SO2 ； The sulfur recovery exhaust emission limit for the process unit is 23 mg/Nm3, which is lower than the 50 mg/Nm3 specified in GB31571-2015 – the emission standards for pollutants in the petrochemical industry (for special areas) ； The wastewater discharged from outside is treated to meet all standards at the park’s sewage treatment plant. The permitted SO2 emission amount for power plant flue gas in 2020 was 132.02 tons, while the actual emission amount was 68 tons, resulting in a reduction of 64.02 tons compared to the permitted level, with a reduction rate of 48.49%. The permitted NOx emission amount from the power plant’s flue gases was 166.96 tons, while the actual emission amount was 143 tons, resulting in a reduction of 23.96 tons compared to the permitted level, or a reduction rate of 14.35%. A total of 4,884 tons of sulfur were recovered throughout the year, and 4,438 tons of sulfuric acid an were produced as a by-product. The energy-saving and efficiency-improving projects implemented by the company in 2020 included: technical upgrades to power boilers to prevent backflow of flue gases and thus save energy; research and implementation of measures to ensure long-term stable operation of the methanol production system; improvements to the pulping system in the gasification unit to enhance its efficiency; upgrades to the methanol distillation process to improve quality and increase output; and modifications to the systems for sampling gases containing sulfur compounds in a sealed manner. As a result of these upgrades, 3.167 million kWh of electricity was saved annually, along with 200,000 yuan in cost savings related to equipment purchases. Our company emits greenhouse gases in the form of CO2; according to calculations, the total amount of carbon dioxide emitted by the company in 2020 was 1,747,282 tons. The company is actively seeking ways to recycle CO2. The first-phase project for supplying 50,000 tons of liquid CO2, carried out in partnership with Lanzhou Yulong Gas Co., Ltd., has been put into operation, and the second-phase project for supplying 100,000 tons of liquid CO2 will be launched at an appropriate time in the future.