Chemical engineering technologies enable the high-value utilization of steel plant exhaust gases

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Chemical engineering technologies enable the high-value utilization of steel industry exhaust gases. Author/Source: Sinochem News Network. Date: August 6, 2019. Clicks: 48. From the much-criticized \"three types of gases\" to valuable raw material resources The exhaust gases that are heavily criticized in the steel industry are regarded as valuable raw material resources by experts in coal chemical engineering. “Promoting the coordinated development of the steel and energy chemical industries, and exploring the use of energy chemical technologies to achieve high-value, environmentally friendly conversion and utilization of industrial exhaust gases from the steel industry, holds great promise. ”At the First National Symposium on Coordinated Development of the Steel and Energy Chemical Industries held recently, renowned scholars and entrepreneurs from the steel and chemical industries reached a consensus. 　　China’s steel production has ranked first in the world for 23 consecutive years. Mao Xinping, an academician of the Chinese Academy of Engineering and deputy director of the Central Research Institute of Baosteel, said, “China is a major steel-producing country, yet as steel production capacity increases, the emissions from the steel industry also keep rising.” Its energy consumption and various waste emissions have become bottlenecks restricting the development of this industry. The exhaust gases produced by steel mills are a major source of greenhouse gases, which is also a key reason why the steel industry faces much criticism. The future trend in the treatment of steel industry exhaust gases is definitely towards high-value and resource-based utilization. ” 　　Steel manufacturing primarily uses iron ore as raw material, and this iron-smelting process generates \"three types of gases,\" commonly known as steel plant exhaust gases. These include coke oven gas, converter gas, and blast furnace gas, whose main components are nitrogen, carbon monoxide, carbon dioxide, and hydrogen. Traditional methods for treating steel plant exhaust gases are mainly heat generation and power production. Due to the high content of nitrogen in exhaust gases, their calorific value is low, making direct combustion economically unviable; moreover, it generates large amounts of carbon dioxide, exacerbating the greenhouse effect. Thus, these “three types of energy” have given Iron Man headaches for decades. 　　However, these “three types of energy” are regarded as valuable resources by Liu Zhongmin, an academician of the Chinese Academy of Engineering and a researcher at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences. “Recently, I spoke with the managers of steel companies and learned that the steel exhaust gases, which they are trying hard to reduce, are actually valuable raw material resources for our coal chemical industry. ”Liu Zhongmin said. 　　In the field of energy and chemical engineering, the main raw materials for chemical synthesis are coal, petroleum, and natural gas. In China, the conditions in coal-producing areas are harsh, there is significant pressure related to coal combustion, and resources of petroleum and natural gas are scarce. Carbon monoxide and hydrogen in steel exhaust are important chemical raw materials. Liu Zhongmin explained, “To produce ethanol from coal, it is first necessary to create syngas, and this process requires substantial investment; its cost accounts for more than one-third of the total cost of the entire project.” By utilizing the existing flue gas resources from steel mills and bypassing the gas generation stage, significant investment can be saved and carbon dioxide emissions can be effectively reduced. ” 　　In recent years, with the support of the Institute of Clean Energy Innovation at the Chinese Academy of Sciences and the CAS Strategic Priority Program A, Liu Zhongmin’s team has developed an efficient and clean conversion method for producing fuel ethanol, utilizing carbon monoxide and hydrogen as the main raw materials. This method is collectively referred to as the DMTE technology – that is, the production of anhydrous ethanol through the carbonylation of methanol/syngas. 　　This is a patented technology in our country that possesses complete independent intellectual property rights. Compared to primary energy sources such as coal, natural gas, and oil, which are used as raw materials in chemical synthesis, carbon monoxide and hydrogen present in steel plant exhaust gases can be purified and then used directly to produce a large quantity of high-value, high-quality chemicals. In January 2017, an industrial demonstration plant for the production of ethanol from syngas with a capacity of 100,000 tons per year was put into operation, utilizing DMTE technology. At the beginning of November of the same year, the E10 ethanol gasoline produced by this plant passed the certification issued by the **Petroleum Fuel Supervision and Inspection Center (Henan)** and met relevant standards. DMTE technology is considered to be the most reliable, stable, and innovative among similar process routes. 　　“In the past, the steel and chemical industries operated independently, each carrying out their activities vigorously on their own. In the future, **the industry must develop in an ecological direction, requiring the establishment of an ecological industrial supply chain with deep integration among related industries. ”Mao Xinping said. But both of these industries are of vital importance; the difficulties and challenges they will face as they integrate more deeply still need to be explored in depth. For example, in terms of the economic efficiency of steel companies, is it profitable or not to convert steel industry emissions into chemical raw materials, as compared to power generation and other exhaust gas treatment technologies? Mao Xinping and Tangshan Company of Hebei Iron and Steel Group conducted an economic feasibility analysis, and the return rate for the latter was about 15% higher than that of the former. “DMTE technology offers advantages in terms of production efficiency, conversion efficiency, and cost, pushing the comprehensive utilization of exhaust gases from steel mills to a new level in the future. However, in the actual process of operation, each steel plant needs to analyze the situation on a case-by-case basis. ”Mao Xinping said. 　　Liu Zhongmin also said that there are many technologies for syngas conversion; enterprises should, based on their own characteristics and taking into account factors such as geographical conditions and market demand, choose appropriate technical solutions carefully. They should not rush to adopt these technologies in large numbers to avoid overcapacity. 　　This conference is supported by the China Petroleum and Chemical Industry Federation, and is organized by the Institute of Clean Energy Innovation of the Chinese Academy of Sciences and the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences.