In September 2020, China presented the "peak carbon dioxide emissions" goal for 2030 and the "carbon neutrality" goal for 2060 to the world. For the steel industry, it is no longer just about quality and output, but also about meeting the requirements of energy conservation, carbon reduction, and environmental protection.
In September 2022, the Ironmaking Branch of the China Society for Metals organized a seminar in Beijing on the energy-saving and emission-reduction technology of hot blast stoves. The conference emphasized the importance of low-pollution and low-emission technologies in the development of energy-saving technologies for hot blast stoves. ANNEC was invited to participate and delivered a report titled "Energy-saving and Environmental Protection Technology of Top Combustion Hot Blast Stove," providing a detailed analysis of the ways and potentials of energy-saving and emission reduction for hot blast stoves. The report also highlighted the technical application and ultra-low emission cases of the cone cylinder rotary cutting top combustion hot blast stove jointly developed by ANNEC and CERI.
A certain steel enterprise in Shanxi has equipped three cone cylinder rotary cutting top combustion hot blast stoves with its blast furnace, which have been in operation for over a year since 2022. Recently, a third-party monitoring agency conducted online tests on the gas emission composition indicators of the hot blast stove system and issued a CMA test report.
The test report showed that the arch top temperature of the hot blast stove was between 1302-1323°C, and the air supply temperature was between 1213-1228°C. The average content of NOx in the flue gas was less than 30mg/Nm³, which is more than 80% lower than the national ultra-low emission standard of 150mg/Nm³, creating significant economic and social benefits for customers.
One of the hot blast stoves of a certain steel enterprise in Hebei adopts a design similar to the Kalugin hot blast stove, with a CO emission level consistently higher than 3000mg/Nm³, exceeding the local emission standard limit of 500mg/Nm³. Under environmental policy control, the plant couldn't operate normally and had to shut down due to immense environmental pressure. After receiving notification from the owner, ANNEC conducted a detailed three-day on-site survey of all hot blast stove of blast furnace, comprehensively understanding various design and operating parameters. Mathematical modeling studies were conducted on the combustion conditions of hot blast stoves under different operating systems, revealing varying degrees of defects in the design of the combustion system. ANNEC formulated a transformation plan for the cool-off, maintenance, and dry-off of the hot blast stove, and under extremely limited conditions, completed the transformation of the hot blast stove burner in 35 days (15 days each for the cool-off and dry-off). The CO content in the flue gas under different operating conditions after the transformation was lower than 350mg/m³, a reduction of 88% compared to before the transformation. Currently, discussions are ongoing with the owner regarding CO transformation projects for several other hot blast stoves, aiming to reduce CO emissions by over 85% in each hot blast stove's flue gas.
Since its inception, ANNEC's cone cylinder rotary cutting top combustion hot blast stove has achieved significant economic and social benefits on nearly 3000 hot blast stoves, making it particularly suitable for global blast furnace construction or renovation projects. ANNEC will continue to focus on the technical innovation of top combustion hot blast stoves and the research and production of supporting refractory materials. By continuously optimizing and upgrading furnace structure and refractory configuration, it aims to achieve ultra-low or even zero emissions of pollutants in exhaust gases, comprehensively promoting the energy-saving, low-carbon emission, and green development of hot blast stoves, and contributing to the smooth realization of the country's dual-carbon goals