Steel pollution reduction and carbon reduction by technological innovation to find a way out


At present, the carbon emissions of the steel industry account for about 15% of the total carbon emissions in the country, and it is the manufacturing industry with the highest carbon emissions in China. Under the "double carbon" goal, reducing pollution and carbon has become the main theme of the steel industry. However, at the recently held 2021 (12th) China Steel Energy Conservation and emission Reduction Forum, Li Xinchuang, chief engineer of the Metallurgical Industry Planning and Research Institute, said frankly, "During the '14th Five-Year Plan' period, the total demand for steel in China's economic development will still maintain a high scale, in the context of the overall scale of steel production is difficult to decline significantly, the total carbon reduction space is very limited. It still takes time for structures to reduce pollution and carbon."

In the view of He Wenbo, executive chairman of the China Iron and Steel Industry Association, the steel industry to reduce pollution and carbon not only rely on comprehensive governance and mechanism guidance, but also need to find a way out in technological innovation.

Great progress has been made in ultra-low emissions. You Yong, deputy director of the Department of Energy Conservation and Comprehensive Utilization of the Ministry of Industry and Information Technology, said that during the "13th Five-Year Plan" period, China accelerated the promotion of green and low-carbon transformation of traditional manufacturing industry, in-depth implementation of green manufacturing projects, and actively cultivated new momentum for green growth, and the green development of industry has achieved positive results and achieved a win-win situation for economic and environmental benefits. For the steel industry, green and low-carbon development such as ultra-low emission transformation has also made great progress. Liu Bingjiang, head of the atmospheric environment department at the Ministry of Ecology and Environment, said China was building the world's largest clean steel production base. Through more than ten years of energy conservation and emission reduction actions, China's steel industry has achieved a double reduction in pollutant emissions and energy consumption with a substantial increase in output and profits, and more and more garden-style factories.

Liu Bingjiang introduced that in 2010, China's comprehensive energy consumption per ton of steel was 640 kilograms of standard coal, sulfur dioxide emissions per ton of steel were 2.89 kilograms, and particulate emissions were 2.2 kilograms. Last year, the steel industry's comprehensive energy consumption per ton of steel fell to 540 kilograms of standard coal, and the emissions of sulfur dioxide and particulate matter per ton of steel were less than 0.5 kilograms, and the indicators were significantly reduced. At the same time, steel production has grown from more than 600 million tons in 2010 to about 1 billion tons in 2020.

According to Li Xinchuang, steel companies account for half of the major air pollutant emissions in the area around Beijing. From 2019 to 2020, by promoting the 50 million tons of steel production capacity in Beijing-Tianjin-Hebei and surrounding areas to fully realize ultra-low emissions, reducing the external transmission of pollutants by about 30%, the PM2.5 concentration in Beijing has achieved "30+" for the first time. In addition, the comprehensive energy consumption per ton of steel in key large and medium-sized steel enterprises in 2020 has also decreased significantly, reaching 545.78 kg of standard coal, down 1.42% year-on-year; Affected by the production structure, technological progress and management improvement, the energy consumption index of single ton steel has decreased significantly.

The steel industry faces new challenges. Although the steel industry has achieved remarkable results in energy conservation and emission reduction, the industry is still the largest source of industrial emissions in China, and it will still face new challenges under the "dual carbon" goal.

First, the steel industry has a high level of ultra-low emission retrofitting standards. Gan Yong, academician of the Chinese Academy of Engineering, pointed out that in China's ultra-low emission standards, the emission of dust, sulfur dioxide and nitrogen oxides per cubic meter of sintered flue gas is 10 mg, 35 mg and 50 mg. In Europe, the above three indicators are 50 mg, 500 mg and 400 mg per cubic meter, respectively. The pollutant standards of each cubic meter of sintered flue gas in Japan and South Korea are also significantly higher than China's ultra-low emission standards.

Secondly, the structural adjustment of the iron and steel industry is also facing new challenges. Li Xinchuang said that the state has not yet issued policies on the total emission indicators of major pollutants and energy consumption indicators with the transfer of steel production capacity indicators, and it is difficult to transfer steel production capacity across regions. At the same time, some places breed local protectionism on steel production capacity due to fiscal and tax pressure, which will also limit the optimization and adjustment of the layout of steel enterprises.

In addition, low-carbon development also puts forward new requirements for the adjustment of the layout of the steel industry. Some areas with insufficient environmental capacity and high pressure of energy consumption reduction will force steel production capacity to be reduced locally, or gradually transferred to areas with better environmental and energy conditions. Li Xinchuang believes that in order to adapt to the green and low-carbon development of the steel industry, while promoting the adjustment of the process structure, it is urgent to rely on the upgrading of process equipment and green and low-carbon technology innovation to solve the problems at this stage. "In the large-scale development of key and cutting-edge technologies that determine the future of China's steel, we must take the road of collaborative innovation, especially in the key low-carbon metallurgical technology, and achieve changes and breakthroughs in the research and development organization." He Wenbo stressed. Li Xinchuang proposed to encourage the demonstration and application of advanced collaborative emission reduction technologies, carry out research on typical industry source and process carbon emission reduction control technologies and equipment, and develop feasible technologies.

In terms of optimization of energy use and process structure of iron and steel, research on advanced process technologies such as efficient pelletizing production process, flux pelletizing production, large proportion of blast furnace pelletizing, and efficient use of block ore in blast furnaces is carried out to reduce the amount of sinter. Research and application of low coke ratio and high coal ratio smelting technology in blast furnace to reduce coke consumption; Carry out research on the use of new and renewable energy such as wind energy, solar energy and biomass energy, and further optimize the energy structure and process structure through multi-energy complementarity.

In terms of strengthening energy conservation and improving energy efficiency, it carries out research on energy efficiency conversion process, equipment and management technology, builds a "trinity" energy management model of equipment, process and system, establishes an energy prediction and scheduling optimization model, realizes the prediction, balance and optimal scheduling of energy generation and consumption, and empowers energy conservation and carbon reduction through lean management.

In addition, it is necessary to strengthen the research and development of innovative environmental protection and low-carbon smelting technology. Li Xinchuang said that the way to achieve deep decarbonization includes hydrogen smelting, electrolytic reduction, oxygen blast furnace and non-blast furnace smelting, and biomass energy utilization. At present, biomass energy does not have the conditions for large-scale utilization, and electrolysis technology is still in the stage of experimental basic research. Therefore, hydrogen smelting, oxygen blast furnace and non-blast furnace smelting will be the focus.