Exploration of the technological pathways for independent coking enterprises to achieve “zero-carbon factories”
Thread Content
According to statistics as of August 2025, there are approximately 500 coking enterprises in China, with a total coking production capacity of 630 million tons; independent coking enterprises account for 59% of this total capacity； The share of coke production capacity held by integrated steel-coking enterprises (including coke plants built by steel companies as part of their operations) is 41%. The average utilization rate of total capacity is around 75%, with a total production capacity for methanol produced from coke oven gas of approximately 14 million tons per year. Recently, five departments including the Ministry of Industry and Information Technology jointly issued the \"Guiding Opinions on Promoting the Construction of Zero-Carbon Factories\", Document No. Lianjie (2026) 13 of the Ministry of Industry and Information Technology. These guidelines state that by 2027, a number of zero-carbon factories should be established in industries such as automotive, light industry, and machinery. By 2030, expansion will be gradually carried out into industries such as steel, non-ferrous metals, petrochemicals, building materials, and textiles, with efforts to explore new pathways for decarbonizing traditional industries with high energy consumption. In accordance with the national standard GB/T32150－2025 \"General Principles for Accounting and Reporting of Greenhouse Gas Emissions in Industrial Enterprises\" ； GB/T32151.13－2023 \"Requirements for carbon emission accounting and reporting – Part 13: Independent coking enterprises\", as well as the standard T/CISA273－2024 and T/CCIAA32－2024 \"Methods and requirements for quantifying the carbon footprint of products – Metallurgical coke\", define the accounting boundaries within the factory premises. Among the total CO2 emissions from independent coking enterprises, the largest share comes from CO2 emitted directly as a result of the combustion of fuel used to heat thermal equipment such as coke ovens, accounting for approximately 80–90% of these emissions ； Indirect CO2 emissions and those from production processes account for about 10–20%.
Adopting the fully dry quenching and double superheat waste heat recovery power generation technology； Utilizing the waste heat from coke oven flue gas and the waste heat from raw gas in the rising pipe to produce steam ； The waste heat from the ammonia water in the coke oven cycle, as well as the waste heat from the gas at the top of the cross-tube pre-cooler, is utilized to generate hot water, which serves as a heat source for refrigeration units to produce low-temperature water ； Using medium-pressure saturated steam as a heat source for the rich oil heater to heat the rich oil, thereby replacing the tubular furnace used for heating crude benzene-rich oil ； Automatic pressure regulation for single-chamber carbonization rooms in coke ovens ； Sealing of coke oven charging hole covers, and automatic sealing technology for quenching coke tanks ； Energy-saving, environmental-friendly measures such as replacing oil-powered loading and transportation vehicles with electric ones within the factory area, converting the desulfurization process that uses carbonates (such as sodium carbonate) as absorbents to other desulfurization methods, can reduce the indirect CO2 emissions of independent coking enterprises to very low levels or even bring them close to zero; any excess heat generated or steam produced within the enterprise can be supplied to areas outside the calculation boundary. The CO2 concentration in the flue gases emitted from the combustion of coke oven gas used for heating coke ovens is 6.25%【1】, which is much lower than that in the flue gases emitted by coal-fired power plants, cement plants, and charcoal kilns. As a result, the devices used to capture CO2 from these coke oven flue gases require more raw materials and electricity, leading to higher operating costs. To date, there are no corresponding carbon capture devices for coke oven flue gas abroad, and the demonstration units for capturing carbon dioxide from coke oven flue gas that have been built and put into operation in China are currently difficult to promote. To address the technical challenges that prevent the widespread application of CO2 capture from flue gases in coke oven chimneys due to various unfavorable factors, efforts are being made to modify the composition of the gas and air used for heating coke ovens, as well as the volume and composition of the flue gases generated during combustion, in order to create a process framework that facilitates the capture of CO2 emitted from the fuel combustion used in coke oven heating.
First, conventional coke oven gas used for heating coke ovens is processed to extract hydrogen, resulting in dehydrogenated coke oven gas, which is then used as fuel for heating the coke ovens. The composition range (%) of dehydrogenated coke oven gas is as follows [2]: H2 3–6 ； CO 9～12 ； CH4 50～52 CmHn 3.5～4.5 CO2－ ； N2 23～26 ； O20.9～1.1, low calorific value 20.92～23.43 MJ/m3. Compared with conventional coke oven gas, dehydrogenated coke oven gas has a lower H/C ratio and a higher carbon content per unit calorific value (tons of carbon/GJ). Dehydrogenated coke oven gas is used as the fuel for heating the coke ovens, and a combined process technology consisting of oxygen-enriched combustion [3,4] + external circulation of flue gas (to counteract certain negative effects of oxygen-enriched combustion on the flame in coke oven heating) + intelligent automatic control of heating (for regulating the heating gas and oxygen-enriched air in single-row combustion chambers) is employed. This combined technology not only helps to control carbon emissions during the coke oven heating process but also facilitates carbon removal from the exhaust gases at the end stage. It can reduce the amount of exhaust gas emitted, thereby decreasing the heat carried away by the exhaust gas, improving thermal efficiency, saving coal gas used for heating coke ovens, and reducing CO2 emissions. Compared with ordinary air combustion, the application of oxygen-enriched combustion increases the CO2 concentration in the coke oven flue gas, which facilitates the capture and utilization of CO2 in the flue gases from coke oven chimneys. The oxygen-containing off-gases emitted by the N2 generation units associated with dry quenching devices or liquid ammonia systems in independent coking enterprises can be considered as a source of oxygen-enriched gas for oxygen-enriched combustion in coke ovens. Applying the above combined process technologies offers advantages in terms of energy savings, carbon reduction, environmental protection, and cost efficiency; it represents a process pathway for independent coking enterprises to achieve \"zero-carbon factories\". By creating conditions favorable for the capture of CO2 from coke oven flue gas, it is possible to use the CO2 obtained through this capture process, along with the hydrogen produced as a by-product of coke oven gas, to produce methanol (there are already examples in China of coking enterprises using CO2 captured from lime kiln flue gas and hydrogen derived from coke oven gas to manufacture methanol).
【Haichuan Spring Festival Tea House: Spreading Good Fortune】On the first day of the New Year, unlock good luck for the whole year! https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5713837 (Source: Haichuan Chemical Industry Forum (Hua Hai Chuan Liu hcbbs))
【3D Process Flow】Summary Post – Useful for learning about the process flow: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5711616 (Source: Haichuan Chemical Industry Forum (Hua Haichuan Liu hcbbs))
【Haichuan Spring Festival Tea House】Old items seen when returning to one’s hometown – do you recognize them? (59) Luxury cars from that era https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5713866 (Source: Haichuan Chemical Industry Forum (Hua Hai Chuan Liu hcbbs))
【Ten Years of Rapid Development in Chemical Processing Equipment】From 2015 to 2026, Yihua will build China’s first project that converts hydrogen sulfide waste gas generated in coal chemical processes into dimethyl sulfoxide of high added value. https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5713557 (Source: Hachuan Chemical Industry Forum (HCHBBS))
【3D Process Flow】Summary Post – Useful for learning about the process flow: https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5711616 (Source: Haichuan Chemical Industry Forum (Hua Haichuan Liu hcbbs))
【HaiChuan Spring Festival Tea House: Spending Money】On the fifth day of the New Year, five blessings arrive. https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5713962 (Source: HaiChuan Chemicals Forum (HuaHaiChuanLiu hcbbs))
【Haichuan Spring Festival Tea House: Spending Money】Happy and joyful on the sixth day of the New Year! ! ! https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5714003 (Source: Haichuan Chemical Engineering Forum (Huahai Chuanliu HCBBS))
【Ten Years of Rapid Development in Chemical Engineering Equipment】From 2017 to 2026, China developed and put into operation the world’s first zero-carbon, regenerative natural gas pressure difference power generation system. https://bbs.hcbbs.com/forum.php?mod=viewthread&tid=5713875 (Source: Haichuan Chemical Industry Forum (HCBBS))